[HN Gopher] Airlines are running out of 4-digit flight numbers
___________________________________________________________________
Airlines are running out of 4-digit flight numbers
Author : jshprentz
Score : 258 points
Date : 2024-08-04 18:46 UTC (1 days ago)
(HTM) web link (viewfromthewing.com)
(TXT) w3m dump (viewfromthewing.com)
| MeteorMarc wrote:
| Give the flights a 128 bit number, so we can give each grain of
| sand on Earth its own flight number.
| gruez wrote:
| Sounds like flight GUIDs.
| poikroequ wrote:
| I'm pretty sure they want to keep flight numbers short because
| that's how passengers identify their flight. As a passenger,
| you wouldn't want to be reading signs with 40 digit flight
| numbers.
|
| Attention passengers, flight
| 3467548742468759027225995322800483168368 to Dallas is now
| boarding.
| netsharc wrote:
| Haha, UUIDs for flights.. that'd be obnoxious.
|
| Maybe use QR-Codes to store/display the UUIDs, and everyone
| should walk around with Apple helmets (what are they called?)
| that scan these codes as you walk around in the airport...
| (Facetious idea)
| karmakaze wrote:
| IPv6 format could at least abbreviate.
| RiverCrochet wrote:
| ::1 is you entering then leaving the terminal
| immediately.
| thaumasiotes wrote:
| > I'm pretty sure they want to keep flight numbers short
| because that's how passengers identify their flight.
|
| That wouldn't describe any passenger I've ever known,
| including myself. We identify our flight by destination and
| departure time. Airport boards are conveniently sorted by
| departure time.
|
| In case of a tie, I'd fall back to airline, also indicated
| separately on the board, but a tie over destination and
| departure time has never happened.
| davchana wrote:
| > Airport boards are conveniently sorted by departure time.
|
| Not true always. Often I see them sorted alphabetically by
| Destination, then time (in west coast US). Or occasionally
| (in middle east) by Airline Name & then Time. All Qatar
| Airlines together. Sometimes even whole LCD Labeled
| (digitally, on screen) as A-E, F-M etc. and a bit
| frustrating way, because often I know my flight
| destination, but not precise time (& sometimes time shifts
| around), sorted by pure time.
| thaumasiotes wrote:
| > Not true always
|
| Except that you go on to describe boards being sorted by
| time? They may also sort by destination or airline, which
| are the other pieces of information that I noted
| passengers already know. You can't use an airport without
| knowing your departure time and airline, and while it's
| technically possible to use the _airport_ without knowing
| your destination (sort of... in point of fact, whenever I
| check in, the clerk invariably asks me where my final
| destination is), that 's not a scenario that's ever going
| to come up.
|
| Nobody knows their flight number, and therefore they
| don't use it for any purpose, including the purpose of
| identifying their flight.
|
| > and a bit frustrating way, because often I know my
| flight destination, but not precise time (& sometimes
| time shifts around), sorted by pure time.
|
| What's the frustrating part? If you don't know the
| precise time, why does that matter? Knowing it to within
| an hour will unambiguously identify the flight.
| aworks wrote:
| In the 1980s, I once boarded a Republic flight from Detroit
| to Houston. Unfortunately, the flight I paid for from
| Detroit to Houston was a different (and direct) one.
|
| In Detroit, there was confusion on the plane as someone
| else had the same seat assignment but they found me another
| seat. They finally figured out I was on the wrong plane
| when we landed in Memphis. I was bounced off a full flight
| and had to wait 8 hours for the next plane to Houston.
|
| Only one of the flight attendants seemed to pay attention
| to the flight number on my boarding pass.
|
| I was also on a flight once to San Jose, California that
| had a passenger who was supposed to go to San Jose, Costa
| Rica.
| wavemode wrote:
| And here I am frustrated because I have a ticket for flight
| 3467548742468759027225995322800483168367 but it took 10
| minutes for me to find out that you weren't addressing me.
| anonfordays wrote:
| This made me chuckle. Some IPv6 zealots are mad!
| Havoc wrote:
| The entire aviation industry feels like it is in need of a tech
| stack 100% rebuild.
|
| Systems like Sabre are 60+ years old.
| tengbretson wrote:
| I don't disagree, but in 2024 where on earth could you staff
| large enough team to do such a task with developers that are
| self-disciplined enough to do it safely?
| gjsman-1000 wrote:
| Heck, where do you get developers who aren't convinced it
| should be rewritten in JavaScript?
| lolive wrote:
| In LLM.
| frumper wrote:
| I wonder if an LLM could write it in JavaScript using a
| blockchain.
| lolive wrote:
| In the Web 3.0, it probably does. In real life, I wonder
| ...
| toomuchtodo wrote:
| A collaboration between the US Department of Transportation
| and the Department of Energy. Lots of solid engineering out
| of Oak Ridge, Argonne, Sandia Labs. Make it a system owned
| and operated by the FAA.
| FireBeyond wrote:
| I'm sure every other country on earth will approve of that.
| This needs to come from IATA, not the FAA.
| toomuchtodo wrote:
| I don't have a strong opinion as to which org owns it, as
| long as it is a neutral non for profit party or other
| consortium arrangement. IATA did not immediately come to
| mind, so I appreciate the correction. Upvoted!
| tengbretson wrote:
| > Lots of solid engineering out of Oak Ridge, Argonne,
| Sandia Labs.
|
| Researchers and academics are quite possibly the last
| people on earth I would ask to deliver safety-critical
| software.
| labster wrote:
| Researchers and academics did pretty well on weather
| models, which are much more important to safety than
| aviation software, because you can't just disable severe
| weather for a few days.
| wenc wrote:
| Weather forecasting is a science problem.
|
| Flight codes -- and making sure they don't break systems
| -- is a software engineering problem.
|
| Different skillsets. I know folks who work at national
| labs. They have neither the skillset nor the interest to
| do this kind of work. (I am a researcher)
| alfalfasprout wrote:
| Strongly agreed. What makes this hard is not something
| novel algorithmically or in squeezing the last little bit
| of performance out.
|
| It's the monumental effort of coordination across many,
| many entities running legacy software and doing so in a
| way that doesn't take down critical infrastructure in the
| process.
|
| It's very, very difficult but in a completely different
| way to building weather modeling systems.
| bollu wrote:
| I am curious why you feel that way.
| alfalfasprout wrote:
| More importantly, they wouldn't be able to pay for the talent
| to pull this off. Also, due to how government contracts work
| it would almost assuredly end up staffed by eg; Raytheon,
| Booz Allen, or some other contractor which would hire bottom
| of the barrel contractors, give them minimal resources, next
| to no flexibility in requirements, and pocket the money.
| gumby wrote:
| Enormous path dependance.
|
| There's a photo in that article that shows the problem: the
| flip-tab sign that has space for four numerical digits. I was
| thinking they could just switch from 0-9 to 0-9A-Z but that
| photo showed why that would be a disaster.
|
| Plus any solution has to be approved for use worldwide.
|
| Fortunately the two-digit IATA codes have already switched to
| 0-9A-Z (e.g. JetBlue is B6) so allowing constrained airlines to
| use two codes should work fine.
| poopsmithe wrote:
| How many airports still have flip-tab signs? Do they need to
| stay? Aren't they adding to an already noisy area? What's
| their maintenance cost vs. a LCD? What's their energy
| consumption vs. a LCD?
| OJFord wrote:
| Same problem on LCD/with the font you use though - those
| displays are dense, and designed around room for 'AB1234'.
| Confusing to have it scroll when it already rotates into
| some other information too.
| selimthegrim wrote:
| I think Russia still does.
| gumby wrote:
| I don't know about the USA but there are likely millions of
| them deployed around the world, and working fine.
| antonkochubey wrote:
| >What's their energy consumption vs. a LCD?
|
| Zero when they're not flipping, and close to zero when they
| are. Even under direct sunlight, to overcome which LCDs
| need >100W / square meter.
| cowsandmilk wrote:
| > I was thinking they could just switch from 0-9 to 0-9A-Z
| but that photo showed why that would be a disaster.
|
| I guarantee those signs could easily be updated for that.
| They're built to allow replacement of each cell and routinely
| do so since cells break. Switching to 0-9A-Z would take one
| night for them.
| eszed wrote:
| To change the physical tabs, sure. What about whatever
| drives the tab-switching? Wouldn't surprise me if it's a
| 1980s solid-state something-or-other with a baked-in 0-9
| constraint.
| prmoustache wrote:
| > Plus any solution has to be approved for use worldwide.
|
| I don't see why for instance you could do a slow roll out by
| using only letters for internal flights of countries that are
| ready for the switch. If you did that at first only for the
| USA that would probably leave enough room for Delta and the 2
| other companies that need them in the short term. And then
| you upgrade the rest of north america: Mexico + Canada, then
| you continue the roll out. I am pretty sure all european
| countries could coordinate to do the switch at a specific
| date in the future as well.
| gumby wrote:
| I thought of this but you need to be able to book flights
| in Europe from, say, Mozambique. Flights from Europe may
| overfly Kazakhstan ATC. And so on. It's a _system_.
| raverbashing wrote:
| True
|
| And that's why they should have started thinking about this
| 20 years ago (or even before that)
|
| Thinking of something like this: every new development and
| maintenance should be done with 5 digits in mind. While
| keeping it backwards compatible for 4 digits
| daemin wrote:
| There was no need to have 5 digit codes or more than 0-9
| for the flight numbers 20 years ago. Arguably there isn't a
| need now. It's 3 airlines in the entire world which have
| this issue because they want to have their own 4000 flights
| plus codeshare more than 6000 other flights from partner
| companies.
|
| This is a problem for people inside those 3 airlines to
| solve within the constraints that the current living world
| has imposed on them.
| pixl97 wrote:
| Ever hear the saying "If you owe the bank 1 million
| dollars it's your problem. If you owe the bank 10 billion
| dollars it's their problem".
|
| You list listed off the largest airlines on the planet of
| which pretty much every other airline has to interoperate
| with. This isn't "AA just has to deal with it", it
| becomes "This is now everyones problem".
| daemin wrote:
| Yes I have heard of that saying.
|
| What I am saying is that "the rest of the world" is
| bigger than AA.
| fellowniusmonk wrote:
| Is this anything other than a problem the big 3 have made
| for themselves for what are essentially marketing
| reasons?
|
| Is codeshare as a "solution" really the best solution or
| is it just the best solution that also meets the
| marketing teams requirements?
|
| Do smaller airlines even care for a solution? Wouldn't a
| global industry wide solution basically be the big 3
| bullying the smaller players to spend tons of money so
| the big 3 can juice their own mindshare?
| slightwinder wrote:
| The problem is more the airlines, IATA and everything else, not
| so much the reservations systems like Sabre. Those airlines are
| annoyingly ignorant with their IT, for whatever reason.
| Sabre&Co. are very active in updating their systems, they could
| probably any time lift the limitations.
| eep_social wrote:
| Been done. You need to put in $100 million to be considered
| serious and get across the table from someone at a carrier.
| Also helpful to have deep relationships with carriers based on
| software for other parts of their business.
|
| And then there's always that risk that some idiotic exec will
| cancel the project to chase a half billion dollar market
| instead. I can't recall where the system needed up being sold
| to but I'm sure it died an ugly death thereafter. Writing the
| core in lisp was a risky move.
| maxsilver wrote:
| Wouldn't the easy solution be to use two sets of letters for IATA
| coded flights for the same airline?
|
| Something like "DL1234" and "DZ1234" for Delta?
|
| I know a lot of the two-letter codes are claimed too, and I'm
| sure there must be some reason this wouldn't work OK, but it
| would seem like they they would each have at least one code left
| over from the various airlines they've acquired over the years?
|
| If an American Airlines regional flight started with "TW1234"
| again, for example, I don't think it would break the world.
| 1970-01-01 wrote:
| This solution is so simple it's what they will do. But only
| after spending millions researching every other solution.
| ronsor wrote:
| And by "researching" we mean overpaying consultants who will
| do absolutely nothing useful.
| Dban1 wrote:
| i wanna be a consultant
| poopsmithe wrote:
| you can be a consultant!
| hiddencost wrote:
| It's honestly really unpleasant spending that much of
| your life hustling people.
|
| I quit after a year because I hated having to hustle to
| make payroll.
| trustno2 wrote:
| You can be, the consultancies are hiring. But you need to
| up your PowerPoint skills.
| xattt wrote:
| Half-serious, but where do I get started?
| trustno2 wrote:
| https://www.mckinsey.com/careers
| jki275 wrote:
| It almost certainly would completely break thousands of
| functions that have those magic letters hard coded into them in
| fortran, cobol, C or whatever. You might even find that clever
| people back in the 70s used other ways of representing those
| letters so you can't even search for them.
|
| I've worked on codebases like this -- I've seen it take a team
| of engineers years to add a single digit to an ID number in a
| multi-million LOC mixed language codebase that was written in
| the 60s.
|
| It's not that it can't be done, it's that it costs millions of
| dollars and takes years and you're never sure it's actually
| done because nobody has ever written a single test for the
| system and if you tried that would take years as well.
| kgen wrote:
| But lots of airlines have come and gone or merged over the
| years and these systems would have already had to deal with
| new airlines codes?
| jki275 wrote:
| Probably true. But their own systems internally almost
| certainly have those magic letters hard coded in thousands
| of places.
| TSUTiger wrote:
| 100% facts. They do.
|
| In prior roles, I've worked at 2 of the largest US
| airlines that have gone through mergers. There are lots
| of hard-coded letters in decades-old code that help
| identify what's mainline, regional, and OA (other
| airline). We're talking everything from reservations
| (booking) to revenue recognition (flight departure).
|
| It would be no simple feat to upgrade the tech stack.
| Hell, some of the mergers are still lingering within the
| systems because airlines wanted to complete it quickly
| for the passengers. The backend, however, has band-aids
| all over the place.
| pixl97 wrote:
| And there is so much functional testing that needs to occur
| on systems boundaries. I'm just thinking of crazy things that
| happen often enough like luggage getting put on the wrong
| flight and shipped via another carrier via agreement.
| jki275 wrote:
| I can start to wrap my head around it a little bit, and if
| I were handed this task I'd run away screaming.
| dataflow wrote:
| That's not such a great solution, it kicks the can down the
| road and it's super confusing to humans to have the same
| airline be represented different ways.
| petesergeant wrote:
| It's common in Asia, with regional affiliates like the
| different AirAsia, LionAir, and VietJet companies having
| virtually identical branding but different flight prefixes.
| konimex wrote:
| I can confirm for AirAsia and Lion Group, and IIRC Ryanair
| also do this with their UK subsidiary with different flight
| prefixes and different aircraft registration numbers.
| kmoser wrote:
| As a traveler, I already know the airline name because it's
| printed on my boarding pass, so I don't really care what two-
| letter prefix they use; to me it's just another part of the
| opaque handle they call a flight number.
| dataflow wrote:
| If only things were always that simple.
| alwa wrote:
| I get the appeal (and the 60 years of accumulated technical
| skeletons, and the business and legal necessity) of keeping all
| of the airline's segments coded as the same carrier and
| notionally able to connect to one another. I do wonder, though:
| in your scheme with a notional "DL" range and a notional "DZ"
| range, would it be feasible to partition the real-world flight
| networks in a way that keeps all the tickets as "same-carrier"
| according to the legacy logic?
|
| That is, could you partition the flight network such that
| nobody has purchased or ever will purchase a single ticket that
| spans flights from both ranges? Assuming maybe that a
| significant number of "backbone" flights (e.g. between hubs)
| can themselves be "codeshared" between the new DL and DZ
| ranges. If so, how much new flight number space could you buy,
| considering the tradeoff between "codeshare all the new DL/DZ
| flights" and "free up the most new flight numbers"?
| sleepytimetea wrote:
| Can they switch to a radix of 36 instead of decimal numbers ?
| tamimio wrote:
| > The computer systems airlines use are built on top of systems
| that are built on top of systems that date back sixty years.
|
| It means it's the time to upgrade the system.
| xena wrote:
| That's like changing the definition of UTF-8. You have no idea
| what is depending on the exact byte order of everything
| spooling out from the core.
| a3n wrote:
| Hexadecimal?
| jbandela1 wrote:
| > Except they don't. American Airlines, Delta, and United are
| running out of flight numbers, and nobody knows what to do about
| it.
|
| All of the above mentioned airlines are the size they are because
| of mergers.
|
| Why don't they use the IATA codes of the airlines they absorbed.
| For example Delta merged with Northwestern. In addition to DL,
| they could also use NW. American merged with USAirways. They
| could use US in addition to AA. United merged with Continental.
| They could use CO in addition to UA.
| nradov wrote:
| That would be a recipe for confusion among pilots and
| controllers. They rely on visual sighting of aircraft for some
| operations and have to maneuver in relation to each other so if
| the livery doesn't match the IATA code then that increases the
| risk of error.
| petesergeant wrote:
| All the baby AirAsias have virtually identical livery with
| different codes (FD, QZ, Z2), doesn't seem to be an issue
| bux93 wrote:
| Since their fleets are based from different home airports,
| the inflight meal selection is different for FD/QZ/Z2. So,
| it actually comes in handy for passengers; no surprises.
| mlyle wrote:
| Here we are talking about running out of codes due to
| codeshares; the planes do not identify themselves this way.
|
| But, similar reasons: mixing branding is going to cause
| confusion (codeshares already do this enough without
| injecting a "third" airline into the mix).
| CPLX wrote:
| That's not really true. The regional carriers like Republic
| and so on have had a variety of different paint jobs (United
| Express, American Eagle) and it hasn't been considered an
| issue. Not to mention the issue of random call signs like
| Brickyard and so on.
|
| And regardless of that we're talking about codeshares
| anyways.
| Dalewyn wrote:
| >For example Delta merged with Northwestern.
|
| Northwest Airlines.
|
| I'm sorry if I'm pedantic, but Northwest was my childhood
| airline flying with my dad on many of his business travels and
| I have many fond memories with them. My Delta SkyMiles account
| hails from Northwest WorldPerks, opened in 1998!
|
| I might also have a soft spot for Delta because of that too.
| pavlov wrote:
| Also immortalized in the Hitchcock classic movie "North by
| Northwest".
| DidYaWipe wrote:
| AKA Northworst.
| lxgr wrote:
| I could imagine many legacy systems identifying "their" flights
| based on the alphanumeric prefix alone (as opposed to doing a
| database lookup).
| globular-toast wrote:
| Yep. Not only a ton of software would make this assumption,
| but a ton of human-based processes too.
|
| Lesson: if you make your IDs easily decodable, people _will_
| decode them and use them directly instead of whatever API you
| intended them to use.
| lxgr wrote:
| According to Hyrum's law, this is an API :)
| Schiendelman wrote:
| That's what happens with requisition numbers for jobs! If
| they're too short (12345), recruiters remember them, start
| building manual processes dependent on them, and then when
| they collide with others on a job board (like Indeed, or if
| the employer hires an agency to help) you end up needing a
| parallel identifier...
| HumblyTossed wrote:
| Switch to hex.
| SoftTalker wrote:
| Or just use letters in addition to numbers in the flight
| number. It woudn't take any more space in the data field, but
| chances are that a lot of them are coded as PIC 9(4) instead of
| PIC X(4).
| linotype wrote:
| 5 digits instead of 4?
| nilram wrote:
| The amount of travel industry software is huge, and a mix of
| ancient and new. Makes sense, but would take years.
| axelthegerman wrote:
| Easy, add a leading 0... Oh wait they probably store them as
| integers, but then it wouldn't matter how many digits... Oh
| wait some places it's fixed length strings
| manquer wrote:
| trailing zero works with integer storage, i.e. old 1234
| becomes 12340 and new flight number could be 12345.
|
| Mentally if the number has significance for sort order etc,
| you can think they are like decimals they would be 1234.0
| and 1234.5, when not set in older systems it can be ignored
| i.e. 1234.0 is same as 1234.
| prmoustache wrote:
| Shouldn't they had started thinking about that 20 years ago
| as to be ready now?
| jcranmer wrote:
| There's a decent chance that several important airline systems
| are storing things in fixed-width fields, so that, e.g., the
| flight number is columns 25-28.
| joshu wrote:
| give the really big airlines some numeric codes that start with
| the right number. For example, give Delta D7 as well. Then they
| can have DL1234 and D71234 etc
| kalleboo wrote:
| I don't even understand the point of code-share flight numbers.
| The first thing I do when I see one is look up the original
| flight number. Most flight search engines will also show you the
| original carrier.
|
| Why not just get rid of them and book on the original flight
| number? Is it needed somehow in their systems to know how a
| flight was booked or what flights are eligible? Can that be fixed
| instead of the flight numbers?
| stephen_g wrote:
| Generally it's easier to book a trip with legs on different
| carriers if they have a codeshare arrangement, because you can
| just do it as a single itinerary through one carrier's web
| site. Otherwise you often need a travel agent to be able to put
| together the itinerary (that's not strictly necessary though,
| just the way they make it work so no technical reason they
| couldn't just offer non codeshare flight numbers)
|
| The other thing is airline points/status - sometimes you get no
| status points/miles on non-codeshare partner flight numbers but
| you do on the codeshare flight numbers.
| kalleboo wrote:
| I guess my question is, is it easier to upgrade the carrier
| website flight booking engines and mileage programs to deal
| with the original carrier flight numbers rather than
| upgrading all of the systems across the industry to deal with
| a larger name space for flight numbers universally?
| bruce511 wrote:
| Also, connections.
|
| If it's a connecting flight, and the incoming flight is
| running late, then the airline "sorts you out". Basically
| they know sboit your connection and make a plan.
|
| I've been on a plane out of Heathrow that waited for a 30-min
| late incoming flight. I've also been on a late flight where
| my connection has been rebooked for me because we arrived
| late.
|
| If you book "2 tickets" you're basically a no-show to the
| first flight, and you're on your own dealing with that
| airline.
| skissane wrote:
| I did that once - book connecting flights on two different
| tickets - and although I ended up actually making the
| connection (despite the first flight running 2-3 hours
| late), the experience was so nerve-racking I swore I'd
| never do that again. It helped that the flight I was
| connecting to ended up running late too.
|
| The reason I did it was it was a personal side-trip (to see
| family) on an international work trip, and although my
| employer would let me mix work and personal travel on their
| booking (provided I reimbursed them for the cost of the
| personal portion), the bureaucracy involved had put me off
| going down that path.
| thaumasiotes wrote:
| > provided I reimbursed them for the cost of the personal
| portion
|
| How does that work, given that the cost of the personal
| portion isn't independent of the rest of the booking?
|
| I was just looking at a flight plan on kiwi.com that they
| could book for $900, with the individual legs costing
| $250, $350, and $500 if booked through the carriers.
| skissane wrote:
| They price two itineraries - one with the work part only,
| the other with both work and personal. They book the
| combined itinerary and then you reimburse them the
| differnce
| RexM wrote:
| Yep, I've done something similar. Flew to a conference
| for work, then had them fly me to my vacation destination
| instead of home.
|
| I basically ended up getting a free one-way flight for
| vacation.
| Pinus wrote:
| I'm not familiar with Kiwi, but I noticed a comment
| thread about them on travel.stackexchange.com recently,
| discussing whether to describe them as "fraud" or just
| "using booking practices that subject the client to
| extreme risks". Be sure to read the fine print on that
| booking!
| thaumasiotes wrote:
| The only problem with them is that they will search for
| and book flights with exactly the maximum luggage
| allowance that you specify, and they don't make this
| clear or really point out that you need to specify an
| amount of luggage corresponding to the amount you'll be
| taking with you.
|
| They will also show you itineraries that result from
| booking separate legs of the flight separately, which I'm
| guessing is what you're referring to. That's not in the
| fine print; you cannot possibly avoid being made aware
| when that's happening.
| kalleboo wrote:
| You don't need to be on a codeshare for that to work
| though, it just needs to be on the same itinerary - the
| flight numbers can be on different airlines and still on
| the same itinerary.
| bsimpson wrote:
| Do you know of any easy ways to book an arbitrary
| itinerary across carriers?
| jachee wrote:
| Sounds like a premium service someone could build. :)
| chx wrote:
| Nope, they can't, either the GDS allows booking it in
| which case it's already possible or the GDS doesn't allow
| booking it and then no app can do it. There are plenty
| services already which allows you to book the craziest
| itineraries. Like, ITA Matrix Powertools can construct a
| clickable link into Orbitz from ITA Matrix searches and
| it doesn't get crazier than that. There's Bookwithmatrix
| too.
| colimbarna wrote:
| Isn't it entirely dependent on the airlines, what counts
| as one itinery? How could I contractually obligate them
| to something they didn't agree to be contractually
| obligated to?
|
| (BTW: I've had multiairline itineraries many times. I
| think a lot of airlines are perfectly happy to do it
| because they can't fly domestic in that country and the
| domestic airline doesn't fly international. Also, there
| have been times when I haven't been able to, and I've
| been worried about it, and I got to the airport for
| manual checkin, and they've said "oh, i see you have an
| ongoing flight to such-and-such, do you want me to check
| you in for the whole journey?")
| kalleboo wrote:
| I don't know about "arbitrary" but most of my travel I
| book with something like Expedia ends up being split
| across carriers without using codeshare numbers. E.g.
| over Christmas I visited my parents in Australia and the
| domestic leg to Tokyo was a JL flight number, and
| international leg was a QF flight number, both on the
| same itinerary/using the same confirmation code.
| lxgr wrote:
| A CRS/GDS locator (PNR, the 6-digit alphanumeric code
| often used to identify tickets, but really only points to
| a GDSs database entry) and a ticket are not the same
| thing, though. A PNR can include non-air travel segments
| like hotels and rental cars too, for example.
|
| That's something very different from a single airline
| issuing a ticket for a complete itinerary, which
| importantly makes them responsible for getting you to
| your final destination in case of missed connections,
| checking your baggage through etc.
|
| If you still have the confirmations or boarding passes,
| you could check for the three-digit numeric e-ticket
| number prefix, which defines which carrier actually
| issued the ticket.
| Dalewyn wrote:
| JAL (JL) and Quantas (QF) are both members of Oneworld,
| so they can share itineraries (and things like frequent
| flyer status and fare class) in a single booking
| regardless of codeshare.
| lxgr wrote:
| Purely speculating, but I always assumed that the
| rationale for code share flight numbers must have been
| something technical, e.g. the airline code indicating
| which airline's database a given record is located
| (ticket, bag tracking code etc).
|
| It's probably not strictly necessary anymore today (as
| you say, I'm pretty sure I've had a ticket across two
| carries without a codeshare number), but maybe it was at
| some point?
| rchowe wrote:
| Generally in order to ticket an itinerary, there needs to be at
| least one flight marketed (e.g. with the airline's flight
| number) by the "plating carrier" whose ticket stock the flights
| are issued on.
|
| I can't buy an itinerary consisting of just BA238 on aa.com but
| I can buy AA6981 which is its codeshare. I can also buy an
| itinerary where I fly AA on BOS-JFK and connect to BA JFK-LHR,
| because there's at least one AA-marketed flight on the ticket.
|
| The marketing carrier also can affect how the operating carrier
| gets paid -- codeshares can have different inventory which
| allows airlines that are partners but not super close to hold
| back inventory for themselves.
| kalleboo wrote:
| Aha! That's a very interesting detail!
| Scoundreller wrote:
| > I can also buy an itinerary where I fly AA on BOS-JFK and
| connect to BA JFK-LHR, because there's at least one AA-
| marketed flight on the ticket.
|
| Dunno if that's a requirement that AA has, but I've totally
| bought 100% Air France metal tickets that don't even touch US
| soil on Delta because Delta sold the same itinerary for way
| less.
| sokoloff wrote:
| You bought them on their DL#### codeshare flight number
| (what [AA or DL]-marketed means in GP's comment).
|
| I fly a lot of "Delta" flights that are entirely KLM or
| Republic metal, often buying the Republic flights with
| Delta points earned on the KLM flights. (NB: the Republic
| airplanes say "Delta" on the side, while the KLM ones say
| KLM.)
| mppm wrote:
| > Why not just get rid of them and book on the original flight
| number?
|
| That couldn't possibly work, as it will make it more difficult
| for airlines to play their bullshit games with inventories,
| differential pricing, status and bonus miles.
| rswail wrote:
| Recently, I flew with gf on Etihad from MEL to CDG, via Abu
| Dhabi. We weren't allowed into the Etihad lounge in Abu Dhabi
| because even though our flight from there to CDG was an Etihad
| code, it was codeshare with Air France.
|
| Believe me when I say I was pissed and made sure everybody
| knew, including the travel agent that booked us that deals with
| high end corporate travellers.
|
| Etihad lost a bunch of business from AU because of that.
| Tor3 wrote:
| That's some particular Etihad setup then? When I travel
| there's often codeshare involved, but as long as the ticket
| (and the boarding pass shows this) is from the airline I
| booked with, then I get lounge access (if my ticket allows
| it) and everything else if there's anything. Doesn't matter
| if the actual flight is with some other company.
| JCharante wrote:
| It sounds like the travel agent's fault for not booking the
| flight properly. Delta Skyclubs have the marketed and
| operated by rule, meaning that if you buy and get the ticket
| issued by Air France then you would have a flight marketed by
| Air France but Operated by Delta. Of course if this was on a
| business class ticket you'd have access to any SkyTeam
| lounges anyways.
|
| Basically your travel agent is incompetent
| zeagle wrote:
| Clearly the successor solution is to use eight groups of four
| hexadecimal digits each, separated by colons. Then each
| individual seat and peanut could be addressed to it's final
| destination.
|
| More seriously the solution suggested of giving the 3 companies
| other unused prefixes like D* U* and A* to use with their
| codeshares and non rev flights to start seems the easiest.
| guardiangod wrote:
| Done forget to have a secondary identifier to further divide
| the seat. I recommend using a short to represent the 65536
| possible slices a seat can split.
|
| Then on the ticket, there would be an extension section that
| tells you the alias of the person that is about to board. We
| can call it SNI or Sitter Name Indicator. Another section could
| be an indicator if the rider is alive when boarding. We can
| call the extension a heartbeat extension.
| Charon77 wrote:
| Given the history of airlines I'm not quite sure if you're
| joking or not. Sounds plausible ngl
| jachee wrote:
| I know explaining a joke always makes it _super_ funny,
| but... this is a NetEng joke about IPv6 being overbuilt.
| dotancohen wrote:
| IPv6 is seen and used directly by professionals, not the
| general public. Overbuilding it in the sense being mocked
| made sense.
| CookieCrisp wrote:
| Which explains why professionals have so eagerly adopted
| it over the last two decades
| dbdoskey wrote:
| Reminds me of the line that network engineers love
| implementing IPv6 so much they have been doing it for
| years
| rvnx wrote:
| We could also have bumped 255.255.255.255 to
| 999.999.999.999 = 1 trillion IP addresses, easy-to-
| remember and backward compatibility with legacy devices.
|
| Modern clients and servers get IP addresses in these new
| whole IP ranges and can communicate together.
|
| Relatively easy to adapt the code of modern software also
| since it's about removing a restriction from a client-
| perspective.
|
| Load-balancers and legacy clients use IP addresses from
| the old pool.
|
| If you have Windows XP you can communicate only to legacy
| IPv4 (in practice only loadbalancers from Cloudflare,
| GCP, AWS and co) and your other legacy stuff. Others
| happily communicate together.
|
| But no, we got this wonderful IPv6.
|
| Sad because it was really doable, theoretical maximum
| below 512 GB of memory for routers to store the whole
| routing table, it's manageable, versus the 2.176x10^22
| exabytes (!) of IPv6.
| davrosthedalek wrote:
| Bad idea, then all the fake IP addresses on Law&order and
| co would suddenly be valid.
| SonOfLilit wrote:
| I'm guessing everyone downvotes you for the very strange
| implication that most software stores IP addresses in
| ASCII. All networking APIs I'm aware of expect IPv4
| addresses as a DWORD.
| rvnx wrote:
| This is the point, instead of rewriting a full stack, I
| would rather change the prototype of these APIs.
|
| To store 999.999.999.999, then you are totally fine with
| a 64-bits INT (QWORD), and there is no struggle to
| backward-compatibility store a 32-bits INT (DWORD) into
| it.
|
| It's more of a matter of doing #ifdef IPV4_EXTENDED
| #define DWORD QWORD #endif
|
| and add an extra IP field inside the IP header packet
| itself that says, "this is the IPV4_EXTENDED DESTINATION
| 5-bytes IP", and the previous field is marked a
| legacy/deprecated.
|
| In fact, it's quite convenient, since we are all INT64,
| sockaddr_in would largely fit in an INT64 for both IP
| itself and the other elements that are in the struct.
|
| https://man7.org/linux/man-pages/man3/sockaddr.3type.html
|
| 5 bytes for the sin_addr field is enough to store until
| 999.999.999.999.
|
| Gives you 3 bytes to store the port etc.
|
| The networking APIs guys could be drinking cocktails at
| the bar by now, if they would change these types.
|
| There is backward compatibility and smaller effort for a
| great impact, and this is beautiful.
|
| It's actually beneficial for the majority of developers.
|
| From the developer of Windows, to the developer of Age of
| Empires, to the developer of a CRUD app on the web (who
| stores IP addresses as a string or as an int), they
| wouldn't see too much struggle to port to int64.
|
| Less than having to build a full new IPv6 experience.
|
| In practice, client apps, at the time you open a new
| socket, if your lib says it wants an INT32 or an INT64 it
| doesn't matter for the developer of that app, since type
| is automatically casted.
|
| time() had a similar situation.
|
| We migrated by adding new bytes, we didn't redefine the
| concept of time.
|
| From a developer-experience, "link to the latest version
| of the network library, oh btw, connect() accepts an
| int64" and remove the UI restriction of 255.
|
| It could even be possible to give compatibility to very
| old software that we lost source-code from by overriding
| the network layer with LD_LIBRARY_PRELOAD or equivalent,
| and patch these softwares by manually NOP the right JGE
| instruction (the asm code for " >= " ) that checks if we
| are over 255.
| immibis wrote:
| and what about the protocol bytes that go over the wire -
| you know, the most important and hardest to change part?
|
| There've been several proposals to make "IPv4 but bigger
| addresses". All of them are just as hard to deploy as
| IPv6. You still need to upgrade all your routers and you
| still need to run two parallel networks.
| Macha wrote:
| So you need to send a message from your host 5.6.7.8 to
| one of these newly enabled hosts 500.600.700.800. You
| update the software on your host, and your target's ISP
| is updated, and your target updates, and we'll even hand
| wave and assume your ISP is updated despite apparently
| having enough legacy addresses to allocate you one.
|
| The message goes out to your ISP router, who then sends
| it to their upstream ISP, who looks at the IP message,
| doesn't understand whatever header you've shoved the
| extended address in, and discards it. Then what's in your
| standard, backwards compatible 32 bit field? The start of
| the address? Does your packet go to some other random
| host on the internet? A placeholder address like all 0s?
| Does your message get discarded?
|
| How do you convince that middleman to update their
| hardware? They have no benefit from it? This is the
| situation IPv6 was in for decades until their literally
| were not enough IPv4 addresses which finally lit a fire
| under companies to start enabling it.
| rvnx wrote:
| (I'm not pushing this idea to the max, I mean, now IPv6
| is here so we'll just go with it, but this is for the
| mental and engineering exercise).
|
| To answer your question, in my model, the legacy IPv4
| field contains the IP addresses of "IPv4 to IPv4 Extended
| bridges".
|
| Let's imagine you want to connect to [example.com]:
|
| Clients who speak IPv4 Extended and their ISP is
| compatible, get the IPv4 Extended answer:
|
| 425.223.231.123 A+ example.com
|
| and directly to it
|
| Clients who speak IPv4 Extended but don't have an IPv4
| Extended compatible ISP, add that extra IPv4 Extended
| header and speak to the bridges.
|
| 425.223.231.123 A+ example.com
|
| 34.23.12.2 BR example.com (the bridge)
|
| Clients who speak IPv4 only but don't speak IPv4 Extended
| don't have to think about IPv4 Extended at all, since
| they will go through the usual layer-7 (typically HTTP)
| reverse-proxy, or a routing based on rules (ip/port
| pair).
|
| Cloudflare does search large scale reverse proxies, it
| works fine in practice.
|
| If someone has an incentive to run such bridges or
| reverse proxies solution, first it's yourself, to save
| your preciouses IPv4.
|
| To the end user the promise is "you will connect faster
| to the internet if you are in native IPv4 Extended
| (because you skip these intermediate bridges)"
|
| We actually have a nice mechanism that we could reuse for
| knowing which bridges to use, it's reverse DNS lookup.
|
| https://www.cloudflare.com/learning/dns/glossary/reverse-
| dns...
|
| In reality this intermediate state with the bridge, is
| not even necessary, so the migration could be even
| easier.
| everforward wrote:
| > In practice, client apps, at the time you open a new
| socket, if your lib says it wants an INT32 or an INT64 it
| doesn't matter for the developer of that app, since type
| is automatically casted.
|
| A lot of networking gear is far closer to an ASIC than a
| general-purpose CPU, so you can't "just change it to
| int64". They were built to process 32-bit addresses, and
| are unlikely to be able to swap to 64-bit without
| enormous performance penalties.
|
| E.g. routing tables would balloon in size, which in
| practice means that you can store far fewer routes.
| Ignoring changes in the size of the netmask, it's 4x the
| size to store 64-bit address pairs, so your route tables
| are a quarter the size they used to be.
|
| The hardware refresh requirements are a big part of the
| reason why IPv6 rollout is so slow, and your proposal
| doesn't avoid that. Getting the software side of things
| to play nice has always been the easy part of this, even
| in IPv6.
|
| > It could even be possible to give compatibility to very
| old software that we lost source-code from by overriding
| the network layer with LD_LIBRARY_PRELOAD or equivalent,
| and patch these softwares by manually NOP the right JGE
| instruction (the asm code for " >= " ) that checks if we
| are over 255.
|
| In IPv6 land, you just encapsulate IPv4 in IPv6 [1]. It's
| a lot cleaner than jankily trying to override
| instructions, especially when the relevant code may run
| on your NIC rather than your CPU and require kernel
| firmware patches (or, god forbid, custom NIC firmware) to
| implement.
|
| 1: https://en.wikipedia.org/wiki/6to4
| chippiewill wrote:
| IPv6 hasn't failed to be adopted due to being over
| engineered. Its failed to be adopted because breaking
| changes are hard.
| nottorp wrote:
| > IPv6 is seen and used directly by professionals, not
| the general public
|
| Yes, that's the problem. It's unusable on your fucking
| home network.
|
| Please, don't post again the 10 "concise" 50+ page
| documents that you "just" need to read to set up ipv6...
| FeepingCreature wrote:
| I don't really understand. My router gives me an IPv6
| address...
| nottorp wrote:
| Do you understand on what basis? Do you know enough to
| assign addresses in a way that you, not your router,
| wants?
|
| Can you ssh/other forms of remote into any machine that
| accepts ssh on your local network using only ipv6?
|
| Can you redirect ports to specific local machines using
| only ipv6 (that implies they keep constant addresses)?
|
| Can you easily switch between two internet connections
| going through different routers that are plugged into the
| same switch for any machine on your local network using
| only ipv6?
|
| Speaking of which, since the ISP decides on the addresses
| behind your NAT, can two separate ipv6 internet
| connections even exist on a local network?
|
| This is all easily doable with ipv4 in like two
| afternoons without setting up anything beyond perhaps a
| dhcp server and some firewall rules. How many additional
| services do you need to do that with ipv6? And how
| enterprisey are they?
| vel0city wrote:
| > Do you know enough to assign addresses in a way that
| you, not your router, wants?
|
| If I want to manually assign addresses it's still pretty
| simple, but in the end I normally just don't care. I
| don't want to know what IP my printer is, I just want to
| reach it. Which isn't a challenge at all. Even for things
| at my home that are IPv4 only they're practically all
| DHCP. Because there's little reason to ever really care
| about something's address.
|
| > Can you ssh/other forms of remote into any machine that
| accepts ssh on your local network using only ipv6?
|
| I have no problems reaching any host on any of my
| networks even if they're running only IPv6. It's nice too
| because I can trivially reach any port I want globally as
| well with a basic firewall change. Even better I can have
| one host have many IP addresses with different services
| bound to each address if I want.
|
| > Can you redirect ports to specific local machines using
| only ipv6 (that implies they keep constant addresses)?
|
| Why do any port redirection at all? Just set the firewall
| rule and things can hit it. And yeah, they can keep
| constant addresses. They can have dozens, hundreds of
| static host addresses if I want.
|
| > Can you easily switch between two internet connections
| going through different routers that are plugged into the
| same switch for any machine on your local network using
| only ipv6?
|
| If that's something you're really wanting, Network Prefix
| Translation can be done pretty easily. But the vast
| majority of home users aren't using dual WAN anyways.
|
| > This is all easily doable with ipv4 in like two
| afternoons
|
| Sounds like your setup with IPv4 took more work than mine
| with IPv6, as mine only took me an hour or so while yours
| took multiple days.
| nottorp wrote:
| > as mine only took me an hour or so while yours took
| multiple days.
|
| Yeah, because the first time I had no idea what I was
| doing, except vague feelings about ipv4 works. Did you
| factor in your pre existing ipv6 knowledge when you
| counted just an hour?
|
| > Network Prefix Translation can be done pretty easily.
|
| What's "easily"? How many services do I need to setup?
| Some other helpful HNer tried to explain to me once and
| the list was like 2 or 3 daemons in addition to dhcp,
| firewall etc.
|
| Do you set up complex ipv6 networks at work?
| vel0city wrote:
| > Do you set up complex ipv6 networks at work?
|
| Your standard was "It's unusable on your fucking home
| network."
|
| I've set up and managed IPv6 at work before, yes. I don't
| know if I'd call them "complex" networks though. Either
| way I set it up at home several years before. And I had
| been running IPv6 at home before I even bothered setting
| it up in a way I wanted, as my ISP's box previously had a
| decently competent SLAAC and IPv6 firewall setup in their
| CPE router. So that took me 0 minutes of time past
| plugging it in.
|
| As for this disdain of running such complicated systems
| like "DNS", so many things support mDNS these days and
| plenty of home routers will automatically update their
| local DNS with DHCP entries. I didn't have to manually
| configure a DNS entry for my printer, I just gave it the
| hostname "brother" when I first set it up and now when I
| need to add it, I just do "brother" on a new computer and
| boom it finds it wherever it is. If I want to check the
| toner level, I open a browser and go to http://brother
| and its there. And even though I've radically changed my
| networking setups over the years, all my configurations
| pointing to "brother" still just work.
|
| > What's "easily"?
|
| https://docs.netgate.com/pfsense/en/latest/nat/npt.html
|
| There's seven configuration options here including the
| Disable/Enable checkbox and a description field.
|
| If you're using ip6tables on your router, it is just two
| commands for a POSTROUTING and PREROUTING nat rules.
| ip6tables -t nat -A POSTROUTING -o eth0.99 -j NETMAP --to
| 2607:xxx::/64 -s fd12:3456::/64 ip6tables -t nat -A
| PREROUTING -i eth0.99 -j NETMAP -d 2607:xxx::/64 --to
| fd12:3456::/64
|
| But hey just complain about how it's just impossible and
| takes so much work instead of actually learning new
| things.
|
| From the sibling comment:
|
| > No, with ipv4 i can just change the default route :)
|
| Are you suggesting you're running around and changing the
| default route on all the devices on your network when a
| gateway goes down? What a nightmare. Just have your
| router have multiple WAN connections and have it do the
| failover for you.
|
| > I have absolutely no problem remembering the last byte
| of any machine on my network
|
| If you want, you can do the same with IPv6. You could set
| your stuff to have your IP addresses be fd12:3456::1,
| then fd12:3456::2, then fd12:3456::3, then fd12:3456::4,
| then fd12:3456::5, etc. Remembering 123456 as your home
| ULA prefix isn't too challenging, is it? You can then set
| up an NPT rule like the one above on your router to
| translate this prefix fd12:3456::/64 with whatever your
| public prefix is from your ISP. Most wouldn't do this
| though, as its essentially the Fisher Price of networking
| designs.
| nottorp wrote:
| > As for this disdain of running such complicated systems
| like "DNS"
|
| Disdain? I run a few bind instances for my own domains.
| On rented servers where they belong. I'm just opposed to
| having one required for my local network.
|
| > https://docs.netgate.com/pfsense/en/latest/nat/npt.html
|
| "NPt makes perfect sense for SOHO IPv6 Multi-WAN
| deployments." Wait, they agree with me. That there are
| SOHO IPv6 Multi-WAN deployments. Who would have thought?
|
| > running around and changing the default route on all
| the devices on your network when a gateway goes down?
| What a nightmare. Just have your router have multiple WAN
| connections and have it do the failover for you.
|
| It used to be that but I don't think any of my internets
| has failed since like 2010... mostly keeping them out of
| inertia. So I've never felt the need to fix the manual
| failover. It's not all devices anyway, just the one I'm
| using at the moment.
|
| > But hey just complain about how it's just impossible
| and takes so much work instead of actually learning new
| things.
|
| Too many new things to be exact. Most of them needless.
| However either people have figured out by now how to work
| around the ipv6 commitee to simplify things, or they were
| always there but whoever tried to explain ipv6 to me
| before had a fetish for enterprise solutions. I
| distinctly remember being told I need to set up at least
| 2-3 extra services for my dual wan setup.
|
| Your answers are almost devoid of acronyms and "helper"
| services that i need to set up and learn because it
| sounds professional. You almost only included firewall
| rules :)
|
| This was not my opinion of ipv6 before. Maybe I'll give
| it a chance in the future. My current setup still works
| "just fine" though so I need to be very bored to fuck it
| up.
| vel0city wrote:
| > "NPt makes perfect sense for SOHO IPv6 Multi-WAN
| deployments." Wait, they agree with me.
|
| Well yeah, without implementing BGP and controlling your
| public prefixes its the only way to have multi-WAN
| deployments, and chances are home users aren't messing
| with BGP. Most users will get by fine just adopting their
| WAN-issued prefixes.
|
| > I don't think any of my internets has failed since like
| 2010... mostly keeping them out of inertia.
|
| So next time you do some big network maintenance just
| drop your redundant WAN connection, sounds like you
| haven't really needed it in _14 years_ (imagine the
| thousands of dollars you 'll save not keeping it another
| decade and a half!). Just adopt whatever public prefix
| you have, and life will be simple.
|
| > Your answers are almost devoid of acronyms and "helper"
| services
|
| Largely because there aren't really many "helper"
| services needed if you're willing to adopt some pretty
| basic network designs. Add DNS/mDNS, and suddenly you
| don't need to care about the specific numbers of things.
| Just accept SLAAC, which comes with any Linux/BSD
| distro/MacOS/Windows/whatever IPv6 embedded stack you've
| got comes out of the box for the last decade+, and
| suddenly you'll get publicly routable IP addresses. If
| you want to access SSH on a box, add a firewall rule for
| its IP and register its IP in a public DNS, and suddenly
| its accessible anywhere. You can make _any_ host in your
| network accessible if you want to. Its nice.
|
| > This was not my opinion of ipv6 before. Maybe I'll give
| it a chance in the future.
|
| I get there's a lot of new acronyms with it digging deep
| in docs. I get it sounds like there's a million ways to
| deploy it. There's a lot to know, if you want to get deep
| in it. Honestly, if you just kind of loosen your reins a
| little bit, accept the things that are already shipping
| on the things you've been running for a decade will just
| work with the newer dynamic stuff, _and adopt DNS_ ,
| it'll probably be perfectly fine. You probably don't need
| to install/configure dozens of additional things.
| nottorp wrote:
| > imagine the thousands of dollars you'll save not
| keeping it another decade and a half!
|
| Uh well, i'm in eastern europe and the fiber i would give
| up on is in a package with the cell phones and the tv
| channels, so i think i wouldn't even notice it missing
| from the bill. And it's all iptv so I don't think I can
| have tv without the fiber.
|
| The other pipe is business ish (symmetrical, no
| restrictions on servers) so I'm not giving up on it, I'm
| using it to give stuff to customers etc.
|
| > I get there's a lot of new acronyms with it digging
| deep in docs. I get it sounds like there's a million ways
| to deploy it.
|
| As i said, last time I asked on some forum (maybe hn,
| maybe ars technica) i got drowned in acronyms. Most of
| them for extra daemons to handle ... some config for a
| larger network, i guess.
|
| And believe it or not, I didn't know until today that you
| can ignore your ISPs prefix and do address translation
| with ipv6 :) I thought you use what you get and that's
| all. Because that was the promise of ipv6 wasn't it? No
| more NAT.
| belorn wrote:
| Do not "ssh/other forms of remote" using ip addresses.
| Use domain names or local domain. It is easier to
| remember, is more secure (if configured in DNS), and less
| prone to errors.
|
| > Can you redirect ports to specific local machines using
| only ipv6 (that implies they keep constant addresses)?
|
| Yes. Use domain names in configuration files. It more
| robust, easier to read, and is better protected against
| network changes on the local network.
|
| I have been part of multiple ISP changes and searching
| through configuration files for ISP specific IP address
| ranges is never fun. It wastes time and is prone to
| errors. In enterprise settings domain names rarely
| changes and even when they do, the old primary name are
| usually retained for backward compatibility. An ISP can
| get replaced fairly quickly if an alternative is cheaper
| or provide a better service.
|
| > Can you easily switch between two internet connections
| going through different routers that are plugged into the
| same switch for any machine on your local network using
| only ipv6?
|
| Are you talking about BGP? BGP is a fairly complex
| protocol and uses some archaic configuration syntax, but
| even so there are generally no differences between ipv4
| and ipv6. It is the same pain making sure both ipv4 and
| ipv6 switch between the two routes correctly.
| nottorp wrote:
| > It is easier to remember
|
| I have absolutely no problem remembering the last byte of
| any machine on my network. Because that's all it takes
| with ipv4 on a sorta complex home network, no need for
| extra services.
|
| > Are you talking about BGP?
|
| No, with ipv4 i can just change the default route :)
|
| Everything is NATed behind the two routers so changing
| the default route changes which connection that machine
| uses. You're thinking enterprise, and then ipv6 becomes
| ... fine. I just have a hack that works fine for me.
| immibis wrote:
| Do you do all this stuff with IPv4? No... especially not
| at home.
| nottorp wrote:
| Yes actually. Think multiple machine home office because
| i WFH, not consumer "just netflix terminals, 3 phones and
| a console".
| vel0city wrote:
| Lots of machines at home and yet having DNS tied to DHCP
| or running mDNS is too much of a hassle.
|
| I would hate to have to remember even the last octet of
| all my machines in my house. Instead it's just the simple
| names. The numbers underneath can all change whenever, it
| doesn't matter. Until I start calling my kids by an octet
| a name will be easier to remember instead of "is that
| north camera 101 or 105 or 113 or..." versus "north-
| camera.my.net" or "is my pool controller 10.7 or 10.8
| or..." Instead it's just pool-pump.my.net.
| nottorp wrote:
| > Lots of machines at home and yet having DNS tied to
| DHCP or running mDNS is too much of a hassle.
|
| Yes. I have no problem remembering the numbers. Illegal?
| vel0city wrote:
| I bet you probably go to this website by visiting
| https://209.216.230.207 since that's way easier to
| remember than https://news.ycombinator.com
|
| I mean why would anyone really care to deal with DNS
| anyways, just a bunch of fluff. Real IT admins just
| memorize IP addresses. Why would I bother dealing with
| all that DNS hassle?
|
| If its easier to remember this site by its name, why
| wouldn't it also be easier to remember what your file
| share's host is by just remembering its name instead of
| some collection of digits? Do you remember people by
| their phone numbers or by their names?
|
| Having functional local DNS is not complicated these
| days. On tons of systems it comes out of the box, you
| almost have to go out of your way to _not_ make it work.
| You need to actively try to _not_ use it.
| nottorp wrote:
| > I bet you probably go to this website by visiting
| https://209.216.230.207
|
| What you forget is on your average home network only the
| last byte matters. The first 3 don't change. It's always
| 192.168.x.y, x is fixed so you only need to remember the
| y.
| vel0city wrote:
| Your average home network has a functional mDNS stack
| already running.
| pasc1878 wrote:
| Mine does not
| everforward wrote:
| Do your devices behind the router get IPv6 addresses, or
| just the router itself?
|
| I wouldn't be super surprised to see routers getting IPv6
| addresses and doing a 6in4 NAT, so devices behind the
| router get IPv4 addresses.
|
| I would be surprised and impressed if your devices were
| actually getting public IPv6 addresses.
|
| IPv6 can be kind of unwieldy, but the bigger issue to me
| is that old and/or very cheap clients (like bargain-bin
| AliExpress IoT stuff) may not support IPv6 at all.
|
| I believe you can run DHCP for both and let the client
| pick one, but then you're into running dual-stack
| routers, and I would be very surprised if ISPs had any
| interest in supporting them for home use.
|
| I may well be wrong, though. I haven't looked into it in
| a few years, because my ISP doesn't support it.
| ianburrell wrote:
| The funny thing is that IPv6 is used more by general
| public more than professionals. Public doesn't notice
| that their mobile network is IPv6, or that there home
| internet also supports it. It is the professionals that
| are dragging feet upgrading the business networks.
|
| More people access Google with IPv6 on weekends,
| currently 46%, than on weekdays, 43%. Presumably because
| mobile and home networks are more likely to be IPv6 than
| offices.
| dotancohen wrote:
| No, IPv6 is the underlying technology behind the general
| consumers' internet connections, but the general public
| is not using IPv6. The general public has no idea what
| IPv6 is.
|
| I.e. IPv6 is used by the general public, but the general
| public is not using IPv6.
| ArchOversight wrote:
| By that same token the general public is also not using
| IPv4. The general public doesn't care, so long as TikTok
| and Facebook appear on their mobile devices.
| dotancohen wrote:
| When you are driving are you using a throttle body?
| Thedarkb wrote:
| When I drive my work van I use a throttle body, when I
| drive my car I use a carburettor. From my point of view
| as a user, I'm just driving a vehicle. The point is that
| users see a holistic system and neither know nor care
| about the underlying implementation details.
| dotancohen wrote:
| > The point is that users see a holistic system and
| neither know nor care about the underlying implementation
| details.
|
| Yes, this is my point too. End users are not "using IPv6"
| even if that protocol is in use to transfer their data.
| pixl97 wrote:
| Router: Do you want to hear an IPv6 joke
|
| IPv4_Device: Yea
|
| Router: I'm sorry, you wouldn't get it.
| nottorp wrote:
| It's ipv6 :)
| immibis wrote:
| Where do zone identifiers come into the picture?
| lxgr wrote:
| Having multiple prefixes per airline doesn't seem trivial,
| given that this historically wasn't a thing. I could imagine a
| bazillion code snippets of if
| flightNumber.startsWith(OUR_AIRLINE_CODE)
|
| that might be incredibly painful to fix on short notice.
| charrondev wrote:
| At least the pain only has to be dealt with by the companies
| that wrote code like that?
| drdaeman wrote:
| Searching a large codebase for a constant (like "DL", plus
| tracing all related variable use if something is assigned
| this or related value), and replacing the logic is a
| relatively easy kind of change. Especially in the modern day
| when we got all those nice semantic analysis and code
| transformation tools.
|
| Especially if they got proper tests.
|
| Certainly way easier than replacing use of a deprecated API
| (and people do this kind of stuff all the time).
| kelnos wrote:
| I think you have an unreasonably optimistic view of the
| current state of most of these code bases.
| rob74 wrote:
| > _the solution suggested of giving the 3 companies other
| unused prefixes like D* U* and A* to use with their codeshares_
|
| That would have the additional benefit of being able to tell at
| first glance if your flight is actually flown by the airline
| you are booking or by someone else. But I'm not sure airlines
| actually want this to be that obvious...
| roshankhan28 wrote:
| No but wasn't this issue was really obvious? like 4 digits
| number ending? could be a technology issue if this was invented
| in the 80's but as time progress the engineers should have seen
| coming this. and why cant we just use the same set of numbers
| again? like a flight from toronto to brazil or any part of the
| world , the flight will always be the same, there will always
| be a set of people that would want to go brazil from toronto.
| it will be easier that way to find the flights online and
| people can even memorize.
| raverbashing wrote:
| > More seriously the solution suggested of giving the 3
| companies other unused prefixes like D* U* and A* to use with
| their codeshares and non rev flights to start seems the
| easiest.
|
| That's exactly it. And what happens in merger situations where
| they keep operating some of the flights with the letters of the
| old companies
|
| The A* space seems full, the D* space is almost full though, U*
| has some space
| https://en.wikipedia.org/wiki/List_of_airline_codes
| ginko wrote:
| Why do airlines even need separate flight numbers for codeshare
| flights? Why not just use the flight number of the operating
| airline in the booking? IMO it's just confusing for passengers
| as well.
| xattt wrote:
| I feel the real reason is also why badge engineered cars also
| exist: market capture.
| ginko wrote:
| I mean sure, but all that branding will fall apart once you
| board the plane and the livery, and everything else is
| branded by the operating airline anyways.
| HPsquared wrote:
| An application for AR goggles, perhaps.
| HPsquared wrote:
| More jobs for everyone.
| mbreese wrote:
| I think the answer is due to money and pride. My guess is
| that the issue is billing and international relations. Code
| shares aren't (often) between airlines that are from the same
| country. So, if you have a requirement to fly a particular
| flag carrier, you have greater flexibility. For example if
| the ticket is funded by the US gov't, you can still take an
| Air France flight, but get billed by Delta. Or, for frequent
| fliers (whom airlines love to target with rewards), you can
| have miles accumulate with United even if you are taking an
| Air Canada flight.
|
| But I would think that this change could be made on the
| backend much easier than trying to add another number to the
| flight IDs.
| delfinom wrote:
| The marketing carrier, aka the one with the airline code on
| the ticket becomes liable for certain things in most
| countries. Codeshare is one way who is responsible is known
| to outside parties immediately. It also impacts automatic
| luggage transfers for layovers.
|
| Not to mention, there are bits where if I buy a JAL ticket
| for AA internationally, I get 2 free checked bags while the
| same AA sold and operated flight has no free checked bags.
| The JAL code lets the airline systems quickly determine they
| can't force you to pay up at the luggage drop-off because you
| are under the other carrier's rules for the flights.
|
| A lot of this is based on the pre-smartphone age but I don't
| think there's better solutions that are both computer, person
| and policy friendly either.
| account42 wrote:
| Most airlines already have vastly different baggage rules
| for different seat classes so I doubt this really needs to
| be determined by the flight number.
| kelnos wrote:
| I feel like you have it backwards: that's exactly the
| point. You buy the flight under the code share flight
| number, and you buy the seat class based on the code
| share airline's (not the operator airline's) seat class
| name. Then the code share airlines baggage rules for that
| seat class flow into that.
| nolok wrote:
| If you think it takes a long time for ipv6 to "take over" in
| the old back bone infrastructure of the internet, trust me you
| have seen nothing compared to making that kind of change in air
| travel back bones.
| belorn wrote:
| The even more simpler solution is to just give up on unique
| identifiers within an airline and simply give each airplane its
| own name space. The existing system of a 4 digits can then
| continue, and all that is required is to use a bunch of
| translation layers to figure out which airline and which plane
| corresponds to a specific flight.
|
| Adding a prefix would mean that all software need to change at
| the same time in order to include the prefix. Adding
| translation layers can be done on top of existing old software.
| eek2121 wrote:
| IPv6 was the worst idea ever and no one can prove me wrong.
|
| The folks that invented it must've never had to deal with a
| mission critical task during a DNS outage, for example.
| ReptileMan wrote:
| Roughly 20 years ago a network engineer I worked with said -
| "We took a look and IPv4 had everything we want and need but
| the address space". Why the committees didn't just made it 128
| bit and be done with it is beyond me.
| immibis wrote:
| They basically did. All the other changes are minor cleanups
| like getting rid of fields nobody uses, and realigning header
| bytes.
|
| Except SLAAC, but that wasn't part of the original design
| anyway. That was an accident when some major vendor
| implemented SLAAC before it implemented DHCPv6. The plan was
| to keep DHCP.
| kelnos wrote:
| The idea that IPv6 is basically just "IPv4 with more
| address bits" is so wildly incorrect I'm not even sure
| where to start.
| immibis wrote:
| You could start with one of the ways it isn't, apart from
| minor cleanups, and apart from SLAAC because it was
| already mentioned.
| drdaeman wrote:
| Just do it right please and make sure every flyer gets at least
| four last groups and two last digits of the fourth group to
| themselves. ;)
| nxobject wrote:
| Record-oriented storage and SABRE strikes again!
| gentle wrote:
| I love that so many people here think they can think about the
| problem for 10 seconds and come up with a solution that hasn't
| already been considered a thousand times and discarded.
| Grimblewald wrote:
| But have they considered 5 digit numbers :^)
| colimbarna wrote:
| I can't believe they haven't started using three digits and
| an emoji.
| Scoundreller wrote:
| No checksum???
| dayjaby wrote:
| The emoji is the checksum
| throwaway2037 wrote:
| Agree. This type of article is classic nerd-snipe fodder for
| the HN masses.
| DidYaWipe wrote:
| Any well-written article should anticipate, ask, and answer the
| obvious questions. For example: Why not use alphanumeric
| characters?
|
| And if the answer isn't known by the sources the writer quotes,
| the writer should say so.
| layer8 wrote:
| Answered in this comment by "hagbard celine" under the
| article: https://viewfromthewing.com/airlines-are-running-
| out-of-flig...
| nailer wrote:
| Very obviously: do not display the hexadecimal code to end
| users.
| bhelkey wrote:
| So now you have three codes, the old code, a new internal
| and a new external code.
| klyrs wrote:
| Don't forget typos
| DaiPlusPlus wrote:
| Two codes.
|
| A competently designed system should be able to convert
| between "internal" and "external codes" using only
| trivial string manipulation (e.g. no external
| dependencies, nor any databases to load at runtime; while
| adding or removing the code type magic-prefix is trivial;
| and computing/veriftying/concatenating/trimming any
| check-digits should also be straightforward, like a CC or
| VIN check-digit.
|
| ...basically, copy what Stripe does (except I wish Stripe
| would announce a far smaller and reasonable length-limit
| for their Object-Ids instead of handwaving around a vague
| reference to needing as 255-char database column -
| because it messes-up all of my RDBMS query-plans' memory
| grants because it allocates (N rows * 255 bytes) whereas
| in reality all of my Stripe Object-Ids are well-under 32
| chars in length, _le sigh_.
| namibj wrote:
| Just set a reasonable limit and set up a column type
| change for if you ever have it exceeded?
| conductr wrote:
| That comment explains the issue but exaggerates the impact.
| Sure, a change can be made and alphanumeric may not be
| right. No it won't be anything like the recent Crowdstrike
| issues. The impact of making a change on downstream systems
| is solved by planning it out. Communicating the intent and
| setting a switch over date. Some people may not heed the
| notices and their systems will crash. That's unfortunate,
| but just like Y2K or other mandatory updates, it must be
| done and when a crash happens it will suddenly become very
| important for that downstream app to issue a patch and at
| least they will know where/why the break happened.
|
| In terms of datatypes, I like the idea of just going with a
| 5 digit integer. It seems fairly straightforward to change
| in most databases/systems. And while having a much smaller
| upper limit, it's 10x bigger than the limit that's taken us
| 60 years to reach.
|
| Also, he mentioned no Alphanumeric datatype in Excel Format
| Cells. It's called General, because it's the default and
| most of that apps user's don't know what VARCHAR is.
| kelnos wrote:
| > _Some people may not heed the notices and their systems
| will crash_
|
| Some of these systems are indirectly responsible for
| keeping people safe and alive. This "oh well, you should
| have paid attention and taken care of it" attitude won't
| fly.
| ksec wrote:
| But then at the bottom of the article it said
|
| >They also still have fun with flight numbers for instance
| running flight 1776 between Philadelphia and Boston; flight
| 1492 to Columbus; _AAA777_ to Las Vegas;
|
| AAA777.
|
| Am I missing something?
| flicken wrote:
| The "AAA" is a typo, they probably mean "AA777" for
| American Airlines 777[1].
|
| A far as why the number 777 is amusing, it's gambling.
| The combination 777 is a jackpot on a slot machine,
| Additionally AA777 is a great hand (full house) in poker.
|
| [1] https://www.flightaware.com/live/flight/AAL777
| partomniscient wrote:
| Interesting. I thought he was more of a submarine guy.
| josu wrote:
| >Why not use alphanumeric characters?
|
| Someone hardcoded that field 50 years ago and it's impossible
| to change the type. It would be easier to just abandon planes
| altogether, and set up a parallel transportation system.
| AnimalMuppet wrote:
| I understand that database conversions (especially
| industry-wide) are hard, but:
|
| > It would be easier to just abandon planes altogether, and
| set up a parallel transportation system.
|
| Yeah, that might be overdoing it _just_ a bit.
| kelnos wrote:
| > _Why not use alphanumeric characters?_
|
| This suggestion is also obviously trivially discarded: it is
| safe to assume that many, many, many systems expect only
| numbers in those fields, and will blow up if they encounter
| letters.
| 1123581321 wrote:
| Still, the speculation is more interesting than the mockery of
| it. If someone is interested in the topic and wasn't invited to
| the airlines' internal discussions, they are necessarily going
| to repeat some of those internal discussions.
| vasco wrote:
| Yeah, I really don't understand the point of coming to a
| commenting website where people comment on stories and not
| expect comments about how they'd do it. Everyone does it at
| least in their mind, and the speculation as a group is the
| most fun about reading the news.
|
| What's the point of reading the news if not to muse about
| "what happens next" or "how we should deal with this" in the
| story of the humans.
|
| Should we sit there going "Welp, I guess someone knows more
| about this than me". If we took that attitude you'd never
| speak about anything.
| TeMPOraL wrote:
| You're no fun. _Obviously_ any such 10-second solution is
| unlikely to work in practice. The interesting part is _why,
| specifically_ a proposed solution won 't work; proposing some
| and having more knowledgeable commenters shoot them down is a
| way to map out the complexities of the real problem quickly.
| It's a very good way to learn.
| ComplexSystems wrote:
| There aren't that many solutions. You can go to 5 digit
| numbers, or use 4 characters with an expanded alphabet, or do
| nothing. What other solutions could there possibly be?
| JCharante wrote:
| Change the way you use the numbers
| indigoabstract wrote:
| Yes, programmers typically like to do that. Btw, how about
| using colors?
| hammadmajid wrote:
| https://en.wikipedia.org/wiki/Law_of_triviality
| slightwinder wrote:
| It's because people don't understand that the problem is not
| finding a solution, but implementing it. This space is simply a
| mess, much more than even your normal messy IT.
| JCharante wrote:
| My solution:
|
| Stop codesharing with marketing flight numbers that are
| useless. Airlines do perfectly fine selling tickets without
| having the flight marketed by themselves and they can handle
| inter-airline agreements without it.
| rhplus wrote:
| Customer behavior is key here. There's perceived risk with
| the dreaded "Multiple airlines" option when booking tickets,
| especially for international flights. No-one wants to find
| out the hard way that there weren't agreements or reciprocal
| status or matching luggage allowances, etc. The code-share is
| shorthand for "we're responsible".
| AnimalMuppet wrote:
| It's also shorthand for "yes, you'll get miles in our plan
| for this flight".
| darylteo wrote:
| If you like a similar problem to scratch that itch there is
| also the 37 dogs problem.
| https://www.youtube.com/watch?v=jMxoGqsmk5Y - a database whose
| primary id had a maximum of 6 digits, but the id was encoded as
| roman numerals.
| david422 wrote:
| Haha nice, entertaining watch.
| alexpotato wrote:
| I think people forget that problems like these have two parts:
|
| - a technical solution that is generally somewhat obvious or at
| least is picking which of 2 or 3 proposed solution makes the
| most sense
|
| - a co-ordination problem that will require hundreds of
| different entities to agree on timelines, rollout plans etc etc
|
| Now, this does happen (Sweden switching traffic side of the
| road [0] an Y2K) every so often but it's a LOT of work.
|
| 0 - https://en.wikipedia.org/wiki/Dagen_H
| dagmx wrote:
| It's the age old problem with software developers.
|
| A problem posited without sufficient solutions is an invitation
| to them to provide a solution for that problem solving dopamine
| hit.
|
| Nevermind that nobody has asked for such a thing or whether
| they're familiar with the problem space themselves.
| alentred wrote:
| Haha, yes. There are always assumptions to make or constraints
| to consider. But they are also often not obvious, so...
|
| A quote by Fry from Futurama comes to mind:
|
| > Zoidberg: All 6,000 hulls have been breached! > Fry: Oh, the
| fools! If only they'd built it with 6,001 hulls! When will they
| learn?
| Cthulhu_ wrote:
| Obviously, the solution is a blockchain and matching
| cryptocurrency where miners can generate flight IDs which the
| operators can then buy off of an exchange. I've already pre-
| mined all convenient and vanity flight IDs for a smooth launch,
| each ID will be sold at an automated blockchain auction with
| prices starting at $1000 each. IDs cannot be reused.
| notfed wrote:
| Aaaaaaand it's gone.
| alfalfasprout wrote:
| Yep. Of course there are ton of solutions that seem better at a
| glance. More digits! Alphanumeric!
|
| Problem is decades and decades of software with the assumption
| of 4 digit flight numbers baked in.
|
| My hunch would be an additional airline code would probably be
| the easiest solution.
| 404mm wrote:
| I have one that I bet the airlines didn't think about: split
| them init multiple smaller companies and restore competitive
| market /s
| angled wrote:
| Obviously the solution is airline code + iata source airport +
| iata dest airport + airline scheduled flight # for the day/week
|
| UA-LGA-LAX-001
|
| LH-LHR-FRA-012
|
| /obviously/
| angled wrote:
| This also doesn't take up any more data, the pnrs have this
| info anyway, it's just reordering it
|
| UA001 from LGA to LAX
|
| LH012 from LHR to FRA
| usr1106 wrote:
| I remember my wife was on a charter flight with 3 initial letters
| many years ago (in Europe). And when I tried to look up the
| arrival, many systems could not handle the flight number.
|
| Now slightly unsure whether I did not dream up the whole episode,
| I did a web search and found
| https://travel.stackexchange.com/questions/157429/what-is-th...
|
| So IATA seems to have formally introduced that in 1994. (Whether
| they have abandoned it again later I don't know.) So big airlines
| could just get a additional 3rd letter(s). The first 2 would not
| have to change, which makes it easier for humans.
| cett wrote:
| It's more likely that the flight in question was using the
| three letter ICAO code in its passenger facing flight number. I
| have never known a three character IATA code to be used despite
| it technically being within the specification.
| Kon-Peki wrote:
| > So for us, and other two big competitors, we found workarounds
| for it. And I think the technology investment would be too
| great...
|
| The is where we all say "not my problem" and don't give it
| another thought. Don't waste your time on these guys.
| edward wrote:
| This is the tipping point that will make the world switch from
| passenger flights to high-speed rail.
| akira2501 wrote:
| I've taken Amtrak. It's honestly not bad service wise. It is
| slow, has the lowest priority on a lot of track, has almost no
| backup options if something goes wrong on the train, and has
| some very old equipment in service.
|
| If it were just twice as fast, was given priority or had it's
| own tracks, and had enough trains that a following one could
| pick you up in a disaster, and without random bedrooms that
| just smell like the 1970s, I would take it almost exclusively.
|
| Otherwise.. sadly.. Amtrak is for when I don't actually care if
| I arrive at my destination or not. If I'm lucky I get where I'm
| going and most of the time I get a steak on the way.
| ars wrote:
| Maybe when a train costs less than an airplane ticket. But
| right now the train costs more and takes longer. Why would I do
| that?
| prmoustache wrote:
| You usually need to factor the whole trip as most trains
| start and stop in city centers while airports are sometimes
| very remote from the cities.
|
| YMMV but where I live, I need to either pay for the parking
| at the airport, have someone shuttle me or take a
| taxi/regional train/bus to the airport.
|
| For domestic use in my country, plane is competitive on
| paper, meaning some flights are much cheaper than train
| tickets. However the cheapest flights are the early and late
| flights which means regional train/bus to go to the airport
| are not an option. Usually you don't want to annoy
| friend/family very late in the morning/night because...well
| that's kind of rude. So you have to either use your own car
| and pay more for the parking than the actual plane ticket, or
| take a taxi that will also cost more than the plane ticket.
| Congratulations! The cost of your trip has already doubled or
| tripled from the advertised price! Now if you haven't thought
| of making your own sandwich add the aditionnal cost of buying
| food + drink at the airport and you will be adding again more
| than the original price of the one-way plane ticket! And that
| is without even mentionning the shady tactics of some cheap
| companies. Take a ryanair flight for instance, and once in a
| while they will ask you to check your luggage in one of their
| bagage check gauge and charge you whenever you have a bag
| that cannot stand upright on its own even if it fits the
| gauge and will force you to pay an aditionnal 70EUR fee.
|
| As for the time, it is also something where you have to
| consider the sum of all. My rule of thumb is regardless where
| I am flying, I know I will lose pretty much half a day. When
| doing sub 3h flights you are usually spending as much or more
| time commuting in/out of the airport and in the airport than
| flying.
|
| On the other hand the train station will allow you to take
| your own drinks, and even if you didn't have time to make
| yourself a good sandwich, and don't want to pay for the more
| expensive options at railway station you will always find
| some cheap takeaways or supermarket close to it. The railyway
| station is usually in a city center as well which may be more
| convenient in many situations and you can reach the railway
| station 5 minutes from the departure time and you will still
| be fine.
|
| Once you have factored all that, the train can often end up
| being the cheaper option, as well as the fastest one if this
| is an high speed train and you don't have to change train.
| ars wrote:
| > as most trains start and stop in city centers while
| airports are sometimes very remote from the cities.
|
| You write that as a negative, but for me that's just an
| even bigger bonus. The only thing I want from a city center
| is how to get _out_ of the city center. I never actually
| want to go there.
|
| I have not personally noticed much difference in commute
| costs plane vs train. Car trips, taxis, and public
| transport, have all been around the same time and cost to
| both. And the plane tickets I've looked at have been at all
| kinds of hours, early, middle of the day, and late. Exactly
| the same with the train, there's no specific pattern.
| (Obviously this is very specific to the location.)
|
| You have a point with the food, it's easier to bring on a
| train - luggage as well, but then again the plane is so
| much faster you don't need to bring as much food.
|
| And I do factor in wait time for an airport, very short
| trips are faster and cheaper in your car, longer trips are
| better in a plane. The train just doesn't really fit in
| anywhere - it's the same speed, or slower, than a car, and
| less convenient. (Even if the train is physically faster,
| getting to/from the station adds so much time the car works
| out faster.)
|
| I book a lot of Spirit flights, and not only are they
| cheaper than a train, they are even cheaper than a bus!
| Every one in a while I go back and check all 3 options, and
| the plane and (occasionally) car win every time.
|
| If you want people to take more train trips they need to
| cost 1/10 of what they currently do, or at least be 5 times
| faster. Without that, well, people just aren't going to use
| them.
| userbinator wrote:
| Then we'll see "Railroads are running out of 4-digit train
| numbers" or similar before long.
| Scoundreller wrote:
| More and more airlines _are_ selling plane+train (or
| plane+bus) itineraries and giving the train system its own 2
| letter value + "flight" number. Might happen.
| Ozzie_osman wrote:
| I hate out-and-back flight numbers (where they reuse the same
| flight number for a flight and for its reverse). It makes it
| really confusing to actually find the flight status and such.
|
| Separately I also find code-sharing slightly confusing,
| especially if you're trying to find out who's actually operating
| your flight for things like checkin counter, etc.
| Animats wrote:
| Yeah, it's like the time the NASDAQ first had more than 65535
| tradeable things.
| hans_castorp wrote:
| The headline is a bit misleading. Because it's not "airlines" in
| general, but:
|
| > and it's really only a problem for three airlines in the world.
| daemin wrote:
| It's 3 airlines in the USA that have this problem because they
| want to add more codeshare flights that other airlines are
| running.
|
| I don't think there will be enough motivation from the rest of
| the world to solve this problem any time soon.
| pixl97 wrote:
| American Airlines has the most flights of any airline on the
| planet. It's kinda like saying "The person that spends $1 a day
| and the person that spends $1 million a day have the same
| standing to a business".
| fareesh wrote:
| Can they have another prefix in addition to "AA"?
| Ekaros wrote:
| Too much consolidation? Time to split up them again?
| bobthepanda wrote:
| Code shares are between airlines that generally operate in
| different markets.
|
| Delta code sharing with Air France may limit direct competition
| on the few international routes they share, but in general it
| is also good for passengers because Delta cannot operate
| flights wholly within Europe and Air France cannot operate
| domestic US flights. Code sharing allows a passenger to buy one
| itinerary complete with rescheduling for missed connections and
| correctly handled baggage.
| rurban wrote:
| They already have a better solution. Did you see AAA777 to Las
| Vegas. So they are able to add alpha to numerics, when needed.
| Return flights sharing the number? Why not.
| lxgr wrote:
| Are you sure that's a real flight number, and you're not
| confusing it with AAL777 (which would be AA's ICAO code, AA
| being IATA)?
|
| I don't think alphanumeric flight numbers are a thing
| currently.
| chgs wrote:
| AF296Q was a flight which crashed in 1988
|
| They are rare though
| the_mitsuhiko wrote:
| They are not very rare. Letter suffixes are very common in
| Europe to avoid potential ambiguity. However they do not
| change the actual flight number portion.
| https://www.flightradar24.com/blog/clearing-up-call-sign-
| con...
| schoen wrote:
| Is that meant to be a slot machine reference? "May all your
| slot machines come up sevens"?
| blahedo wrote:
| I'm remembering the ISBN switch, which I thought would throw off
| some older systems--and it probably did, but it took so long to
| happen that the transition ended up being pretty smooth. The key
| element was that for a solid ten years or so, every book had both
| an old-style and a new-style ISBN (and possibly some still do).
|
| I'm _hoping_ that behind the scenes they really are looking at a
| better plan than just "work around it", but the workaround can
| buy them time; and if their operations plan is strong, they'll be
| able to roll it out very slowly in parallel while all their back-
| end stuff gets upgraded. (This would require some aspect of the
| new system to make it immediately distinguishable from the old
| one, e.g. three-letter airlines or whatever, but that's a minor
| detail compared to all the other stuff they'd have to work out.)
| Bonus points if knowing the "old" number lets you algorithmically
| derive the new one somehow, and vice versa, to make the
| transition period easier. :)
| philjohn wrote:
| I still love the bit of book trivia that since 13 digit EAN's
| start with a country code, you can convert an ISBN-10 into an
| ISBN-13 by prepending it with the code for "book land" - 978.
|
| (I worked on Library Management Software for 6 years).
| bloak wrote:
| You also have to recompute the check digit, of course, for
| example: 0131103628 -> 9780131103627
| slightwinder wrote:
| > I'm hoping that behind the scenes they really are looking at
| a better plan than just "work around it",
|
| Airline-IT is mostly just a big pile of workarounds to cope
| with limitations from 40+ year old systems. I've worked with
| reservation systems and seen their modernizations through the
| years. Modern xml-formats shoving megabytes of data for every
| reservation. They are very wasteful, generously designed with
| redundant fields, long feature-lists and all kind of annoying
| shit. But at the end, your whole booking can still drip on the
| passenger's name being one character too long. Even after
| decades and multiple iterations of interfaces, at the core the
| systems today still depend on whatever someone in the 1960s
| considered as good enough for the US-market.
| NeoTar wrote:
| I wonder if I see an earlier version of this problem - I take the
| flight BA988 from London to Berlin a few times a year, and in
| some systems it will appear as BA0988 - possibly because some can
| handle 3 digit and some neee 4 digit flight numbers.
| roshankhan28 wrote:
| as you are a person who takes the same flight frequently , wont
| it be easier having the same flight number ? the flight
| companies should just make the flight numbers fixed for a fixed
| route, like local buses.
| NeoTar wrote:
| I'm a little confused by your comment - Airlines do re-use
| flight numbers - BA988 is always the BA flight from LHR to
| BER at around 19:30 (i.e. there will be a BA988 today, there
| was one yesterday, and there will be another tomorrow).
|
| But to be honest, I'd also say it's not that useful for me
| personally. It's a lot easier to remember your destination
| and fight-time - (i.e. I'm on the 19:30 to Berlin) than a
| flight-number, and only once do I think there was ever the
| potential for confusion).
|
| [You experience may vary, especially if you are are used to
| flying a busy flight corridor.]
| blitzar wrote:
| I have carefully read the entire thread and nobody has said the
| answer yet.
|
| Blockchain Ai.
| xipix wrote:
| The biggest challenge here isn't the tech/standards problem.
|
| It's what this signals for the future of the planet's climate.
| tgv wrote:
| Indeed. Just reduce the number of flights already. That should
| give room in your 4-digit space.
| pmontra wrote:
| If it's a problem for only 3 airlines in the world, give them a
| new two letter code, if there are any of those codes left. So
| airline AA will start using also code ZZ for some of their
| flights. Travelers will be a little puzzled at first but they'll
| stop noticing soon.
|
| I sorted the airlines by two letter codes [1] and the list is
| pretty busy but hex 20 for Space is still available.
|
| [1] https://en.wikipedia.org/wiki/List_of_airline_codes
| yread wrote:
| You can do it like Easyjet. They have normal easyJet EZY, easyJet
| Switzerland S.A. EZS, easyJet Europe Gmbh EJU. Problem solved. OK
| they have a lot fewer planes than United but 99% of their flights
| are short (<3h) so they probably need similar number of flight
| numbers
| deanc wrote:
| Anyone who's worked doing any kind of IT for the aviation
| industry knows how much of a clusterf*ck the spec for PNR is.
| Flight codes are the least of the limitations there.
| amelius wrote:
| Why are they bothering passengers with flight numbers?
|
| If computers were like airplanes, programmers would show pointers
| to users.
| 11235813213455 wrote:
| Maybe the opportunity to raise price really high and save the
| planet
| jillesvangurp wrote:
| A lot of the software used to coordinate this stuff is very
| ancient at this point. The fix is straightforward from a
| technical point of view but super complicated to implement
| because it involves replacing/fixing half a century old software
| systems in use in thousands of companies across the industry.
| Probably a lot of cobol and other crap that is still in use for
| this.
| pantulis wrote:
| And if you thought flight numbers are complicated, wait until
| you see what is in the future for PNR codes:
|
| https://www.iata.org/en/programs/airline-distribution/retail...
| heisenbit wrote:
| Maybe, just maybe the solution is to stop flight code sharing.
| Having one flight under different numbers is confusing at best
| and feels misleading. Just imagine giving airlines more space to
| spam everyone with a magnitude more numbers. Just picture
| announcement boards at airports...
| jll29 wrote:
| > Here's the full answer, along with how they triage the problem
| - for instance by assigning the same flight number to more than
| one flight a day (although that means they need for it to be
| flights that would never both be in the air at the same time,
| such as where the same plane is used and can't reasonably be
| substituted)
|
| This sounds like it's calling for trouble!
|
| Whenever I hear that any IDs could be "recycled", I make a mental
| note to replace the person making such a proposal from all teams
| that I am involved in.
|
| The worst is I once was put to work on a system where they even
| recycled GUIDs... I thought "which part of GUID do you not
| understand, the G part or the U part?" (from which it follows
| they also don't really understand what ID means)...
| snapcaster wrote:
| >Whenever I hear that any IDs could be "recycled", I make a
| mental note to replace the person making such a proposal from
| all teams that I am involved in.
|
| Couldn't agree more, not even interested in debating it
| regular_trash wrote:
| The misconception here is that Flight numbers are not treated
| as IDs. A unique key to any flight is the composite of
| number/origin/departure date.
|
| And it's mostly a holdover from legacy systems airlines are
| entrenched in, so there isn't much else anyone can do here
| short of completely reinventing the mainframe reservation
| systems and heavily refactoring all the pieces that depend on
| it.
| RaftPeople wrote:
| > _Couldn 't agree more, not even interested in debating it_
|
| Given that the industry has rejected the natural but very
| expensive solution, and that airlines exist in a connected
| space, this information is shared with partners and external
| parties so they can't just change their internal systems, it
| doesn't seem like there are too many solutions.
|
| One solution could be to assign multiple airline codes per
| airline, but I'm not sure of the downsides.
|
| Do you have a solution you think would work?
| zwily wrote:
| Flight numbers are already recycled (sometimes on the same
| day). The proposal is just changing the recycling frequency.
| drivers99 wrote:
| This whole argument reminds me of something. Found it. (Can't
| believe that was only 2 months ago.)
|
| You'll regret using natural keys
| https://news.ycombinator.com/item?id=40580549 (554 comments)
| iicc wrote:
| Last year the UK ATC system crashed when it "encountered an
| extremely rare set of circumstances presented by a flight plan
| that included two identically named, but separate waypoint
| markers outside of UK airspace".
|
| https://www.nats.aero/news/nats-report-into-air-traffic-cont...
| eknkc wrote:
| Hey they are inventing NAT. Nice.
| zaphoyd wrote:
| NAT for airline flight numbers would fix this problem and
| improve security to boot!
| kqr wrote:
| Wait, how are they doing that? My mental idea of NAT is that
| it dyanmically links (address x port) pairs to local
| addresses. What would be the "port" in the case of flight
| numbers?
| kevin_thibedeau wrote:
| origin,destination tuples.
| BillTthree wrote:
| UTC Date + Time of flightplan takeoff
| kqr wrote:
| If that would be usable and could be assigned at
| sufficient precision the flight number would not be
| necessary at all!
| mschuster91 wrote:
| > This sounds like it's calling for trouble!
|
| It is, and from what I hear it's routinely causing hiccups in
| the German freight train network with its sometimes really
| ridiculous delays that sometimes can add up to > 24 hours.
| tyingq wrote:
| >Whenever I hear that any IDs could be "recycled", I make a
| mental note to replace the person making such a proposal from
| all teams that I am involved in.
|
| I understand the sentiment, but in this case, someone is trying
| to solve for constraints they didn't invent.
|
| Flight number was fixed to 4 digits long ago and propagates out
| to a lot of different systems, many not in the same company as
| the airline, also many being government entities.
|
| So they don't have a lot of great choices.
| whizzter wrote:
| Seems to me like an ego issue honestly since the article
| points out that a large part of the bloat is from
| codesharing, using the actual operators code feels like an
| obvious solution unless egos are too fragile.
| kelnos wrote:
| It's not ego, it's marketing, loyalty, and customer
| comfort.
|
| Passengers don't want to see "multiple airlines" in their
| itinerary. They wonder if the baggage allowances are the
| same, and if those bags will make it all the way to the
| final destination. They wonder if they'll get miles on
| their "main" airline for the whole trip, or if it will be
| broken up between different loyalty programs. They wonder
| if the connection is actually doable time-wise, and if
| there's a delay, will the airlines work together to either
| hold the next leg for some amount of time, or rebook
| without hassles and fuss and each airline pointing at the
| other, claiming it's not their responsibility.
|
| Codeshares solve all these problems.
| cobbzilla wrote:
| Have you ever changed the static IP address of a computer? You
| just "recycled" a "globally unique" ID.
|
| Recycling unique IDs (more precisely: changing the underlying
| thing the ID points to) is not impossible; there's lots of
| pathological failure modes; for certain ID-spaces it's kinda a
| required use case; so we have to deal with it.
| vel0city wrote:
| IP addresses (especially IPv4) are not even supposed to be
| globally unique.
|
| How many 192.168.1.1 devices are out there? How many
| different distinct physical boxes respond to traffic going to
| 1.1.1.1?
| cooljacob204 wrote:
| You're right but for the wrong reason. You are referencing
| the private blocks that are designed for private use. The
| vast majority are not designed for private use.
|
| The reason it's not unique (using my rudamentry
| understanding of networking) is because multiple routers
| can broadcast the same IP so devices can use the closest
| router.
|
| However I think it's fair to say IP address are intended to
| be unique to an org while private ips are not.
| vel0city wrote:
| > You are referencing the private blocks that are
| designed for private use.
|
| Sure, but the person I'm replying to wasn't making a
| distinction here. They're just saying, "Have you ever
| changed the static IP address of a computer", where does
| that exclude RFC1918 IP addresses? I'm right for the
| right reasons IRT to the person I'm replying to. There
| are IP addresses which are _absolutely_ not globally
| unique in any way, shape, or form _by design_.
|
| > I think it's fair to say [public] IP address are
| intended to be unique to an org while private ips are
| not.
|
| "Unique to an org", that's massively different from
| "globally unique" which is what the person I replied to
| suggested.
|
| > multiple routers can broadcast the same IP so devices
| can use the closest router.
|
| 100% correct here, that's the biggest reason why you'd
| have an IP address shared among a lot of different
| devices.
| crmd wrote:
| Real talk.
|
| I've been working in tech for 20 years, am coming off a
| year-long sabbatical, and for the past couple of months
| have been struggling with the feeling that the joy is
| gone and I should consider a radical career change.
|
| Reading (what feels to me as) the aggressive pedantry of
| parent commenter in this thread is giving me a straight
| up anxiety attack. I'm not sure I have it in me anymore
| to be in meetings with people whose brains work this way.
|
| Is it like this in every industry or is it more
| concentrated in tech? I don't know who's going to see
| this, but if you have any perspective or feedback you'd
| like to share, I'm all ears.
| vel0city wrote:
| If someone says, "Tom Hanks played Jon Snow in Game of
| Thrones", and then you reply "that's incorrect, it was
| Kit Harrington", and then people say "well it's really
| Tom Hank's cousin that played him", which is _still
| incorrect_ , is it aggressive pedantry to point out
| that's still wrong?
|
| IP addresses are not globally unique. IP:PORT is not
| globally unique. Kit Harrington played Jon Snow in the
| HBO series Game of Thrones. These are just cold, hard,
| facts.
|
| Looking for real feedback here, as I don't really want to
| give anyone panic attacks, but what would you suggest I
| say to posts attempting to correct me saying I'm wrong
| when I know they're factually incorrect? Just accept the
| falsehoods?
| averageRoyalty wrote:
| I've had hyper-pedantic arguments in many workplaces, but
| they're usually focused in tech or other "intellect
| driven" fields.
|
| A lot of people (Americans especially, I guess due to
| their Silicon Valley) think you need to work in tech to
| work in tech. There are tech jobs in every industry, both
| IT and other types of tech. I recommend not being in the
| tech industry - working for a manufacturer with embedded
| systems or doing IT for a finance company is a lot better
| for your mental health.
| rand_r wrote:
| Because of NAT, it's actually "IP + Port#" that is globally
| unique, and ultimately associated with a single physical
| network interface on a device (e.g an ethernet port on a
| PC).
|
| There's exceptions like broadcast IPs, but the point is
| that it is a system for uniquely locating devices and
| listening OS processes with IDs routinely shifting around.
| vel0city wrote:
| > it's actually "IP + Port#" that is globally unique
|
| So which globally unique box is 192.168.1.1:443? Can you
| point to exactly _one_ device out there with that IP:PORT
| combo? There 's probably hundreds of millions of that
| IP:Port combination currently running and listening.
|
| Which globally unique box is 8.8.8.8:53? You think
| there's seriously just _one_ network adapter listening
| for traffic at 1.1.1.1:53? These aren 't "broadcast IPs".
|
| https://en.wikipedia.org/wiki/Broadcast_address
|
| And even then, "ultimately associated with a single
| physical network interface on a device" isn't correct
| either. You can have multiple physical interfaces
| listening on the same IP and end up with the same ports.
|
| https://en.wikipedia.org/wiki/Link_aggregation
| rand_r wrote:
| Well the 192 case would probably have an external IP +
| Port uniquely mapped to it in the router's NAT table. I
| think you're missing the larger point though. No one said
| IPs are exclusively used as GUIDs. Just that they are
| used as GUIDs, which they are in the majority of cases,
| and those GUIDs are re-assigned over time.
|
| My Macbook Pro currently has unique IP + Port, associated
| with a single process listening to it over NAT and
| packets you send are routed to its network interface.
| Next week, someone else's laptop could have that same IP
| + Port. That's the main idea here, not these exceptions.
| vel0city wrote:
| > would probably have an external IP + Port uniquely
| mapped to it in the router's NAT table.
|
| Only on really crappy NAT implementations. My home router
| can have hundreds of thousands of NAT states, and yet
| there are only ~61k high number ports. How do you think
| that works?
|
| Because it is not just "external IP at this port goes to
| this LAN host". Its the whole session information,
| SRC_PORT, DEST_PORT, SRC_IP, DEST_IP, all get figured
| into it.
|
| At this moment there are several NAT states in my home
| router that share the same public IP:PORT combination,
| going to different LAN IP:PORT combinations.
|
| An IP address is not globally unique. An IP:PORT is not
| globally unique. Treating them as globally unique shows a
| misunderstanding of networking concepts. They're _often_
| unique to a single host, but that 's not a requirement.
|
| Once again, do you really think there's a _single_
| network adapter out there that has 8.8.8.8:53?
| BillTthree wrote:
| there are a handful of ranges in IPv4 that are NOT globally
| unique. You're describing a much smaller set of IP ranges
| that are designed to be used+reused but not routable.
|
| if you take someone elses public IPv4 address and they're
| using it, neither one of you will be functional, and they
| will come knocking on your door.
| vel0city wrote:
| > if you take someone elses public IPv4 address and
| they're using it, neither one of you will be functional,
| and they will come knocking on your door.
|
| Sure, but if I have the IP address 1.2.3.4 I can have
| _lots_ of unique physical things have that publicly
| routable IP address and have them all work if I do it
| right.
|
| https://en.wikipedia.org/wiki/Anycast
| immibis wrote:
| They are most definitely designed to be globally unique,
| and we fucked it up.
| vel0city wrote:
| If that was supposed to be the case it's been fucked up
| since they first gave 19.0.0.0/8 to a car company in
| 1988, or when IPv4 was originally designed with such a
| small address range.
| kzrdude wrote:
| The neat thing is that the replaced person frees up their ID
| which can be reused by the new employee coming in, just easier
| that way.
| xhkkffbf wrote:
| Isn't this what Southwest essentially does? I've been on a
| Southwest flight that makes four or five stops, all with the
| same number. But I'm sure no person took more than one stop on
| the same plane.
| berti wrote:
| It works well enough for trains too. On those you get to stay
| onboard for multiple legs though, and I believe that's quite
| rare for flights.
| vel0city wrote:
| No, that's still one flight path just with several stops. So
| there's not more than one plane in the air with the same
| number. There's a difference between a flight "continuing on"
| and an entirely different flight plan. And I dunno, there's
| probably _some_ percentage of riders who might continue on
| past a single stop. It 's not impossible.
|
| For example:
|
| https://www.southwest.com/air/flight-
| status/path.html?depart...
|
| There won't _also_ be a SW981 today that say takes off from
| HOU to OKC.
| ryukoposting wrote:
| I'm certain each flight has its own completely unique ID buried
| somewhere in a database. But, shorter codes can be spoken into
| a radio faster and with lower probability of misinterpretation
| - both critical features for air traffic control.
|
| Those shorter codes will necessarily be reused, it's just a
| question of the time interval between re-uses of any particular
| code.
|
| I faintly recall seeing two Southwest flights from ORD to BWI
| that had the same code a couple years ago, so I decided to look
| it up. And yes, it's a thing: Flight 1555 from ORD to BWI
| departs at 4PM today, and flight 1555 from ORD to BWI departs
| at 4:20PM tomorrow.
|
| I'm curious, can anyone find a re-used code on a shorter time
| interval than that? It seems like 24 hours is perfectly
| reasonable, but how narrow can the window be? 12 hours? 6?
| SirMaster wrote:
| I thought that airlines that fly the same origin to
| destination daily at the same time always use the same flight
| number for that flight each day.
|
| At least that's what I feel like I normally see.
| DiggyJohnson wrote:
| Not always but often.
| SirMaster wrote:
| Yeah, always was being generous. Often is probably an
| accurate qualifier.
| regular_trash wrote:
| There are usually flights from hub to spoke, and spoke to
| hub, and each one will have the same number. This is within a
| 24 hour period. 3934 is one such flight between PHX and SEA.
| cameronh90 wrote:
| Tangentially, train 'headcodes' in the UK are not unique for
| various historical and convenience reasons. They're supposed
| to be unique within a given 'area' and period of time, but
| it's not very well specified what either of those are.
|
| It rarely causes problems, but very occasionally does.
| 0xffff2 wrote:
| This is true in the US as well. For example, all northbound
| trains on Amtrak's Coast Starlight route are train 14 and
| all southbound trains on the same route are train 11.
| There's currently a train 14 west of Los Angeles that
| originated this morning. Meanwhile train 14 that originated
| in Los Angeles _yesterday_ is a couple hours from pulling
| in to Eugene, Oregon. Likewise there 's a train 11 that
| just departed Seattle and another train 11 that's just
| about to pull in to San Jose.
|
| I assume that in theory any given train #/station/date is
| unique, but given Amtrak's notorious delays, I'm sure that
| theory has been disproven at least once.
| delta_p_delta_x wrote:
| > I'm certain each flight has its own completely unique ID
| buried somewhere in a database
|
| There is. It's called the Globally Unique Flight Identifier
| (GUFI), and it's essentially a UUIDv4[1].
|
| [1]: https://docs.fixm.aero/#/general-
| guidance/flight_identificat...
| rappatic wrote:
| This line made me chuckle:
|
| > The `Aircraft Identification` is NOT an identifier of an
| aircraft. It is an identifier of a flight.
| tivert wrote:
| >> I'm certain each flight has its own completely unique ID
| buried somewhere in a database
|
| > There is. It's called the Globally Unique Flight
| Identifier (GUFI), and it's essentially a UUIDv4[1].
|
| Great, step one cleared.
|
| Now have _all_ the legacy systems everywhere that use
| 4-digit flight numbers been updated or replaced?
| trueismywork wrote:
| 4-digit flight numbers are for humans, not computers
| andrewstuart2 wrote:
| Humans write the code that makes those computers do
| things, though. And humans don't always read the
| standards, docs, or manuals before doing so.
| zeeZ wrote:
| But humans, who interface with computers, are known to
| cause trouble.
| taneliv wrote:
| Like the mechanical displays at various airports across
| the world pictured in the article?
|
| Overall seems like a project of huge size and somewhat
| unknown reach. Not my domain, but I would imagine all
| kinds of ground support systems to have the four letter
| flight numbers baked deep into their assumptions. And not
| only direct support like fuel, cleaning, work shift
| scheduling, but also logistics systems for cargo,
| military systems, myriad of ticketing systems etc.
| andrewstuart2 wrote:
| Please tell me it's pronounced "goofy."
| madcaptenor wrote:
| Short flights out-and-back from a hub can have the same
| number on the two legs. An example is AA 1992, which today
| departs PHL 3:06 PM, arrives ATL 5:17 PM, departs ATL 5:57
| PM, arrives back at PHL 8:05 PM. (All times US Eastern.)
|
| My mother recently had an itinerary where both her flights
| were this flight - the PHL-ATL leg on a Sunday and the ATL-
| PHL leg on the following Saturday.
|
| (It looks like as of Tuesday AA 1992 becomes a DFW-SEA-DFW
| flight, but it's the same sort of thing.)
|
| I figure this isn't a problem as long as the two legs are
| flown by the same plane. But what if the PHL-ATL flight were
| delayed and American decided to fly the ATL-PHL flight as
| scheduled with a different plane (say because lots of people
| booked on that flight had connections at PHL?) That seems
| like it could create trouble.
| zwily wrote:
| I recently flew SLC-CLT and CLT-SLC, and both flights were
| DL2070.
| madcaptenor wrote:
| I've also seen this on Delta on ATL-PHL. I had guessed it
| was limited to relatively short flights - because why
| waste a number on a short flight, and because there's
| less room for irregularity where you end up with both
| flights in the air at the same time - but it looks like
| at least SLC-CLT on Delta and DFW-SEA on American do it.
| zrobotics wrote:
| If they had to switch to a new plane, wouldn't they also
| need to refile the flight plan? From what I understand that
| would be the case, so either a new number would be assigned
| or the details would be updated in the system. I'm not a
| pilot, I know a few instrument rated pilots but they're
| private, not commercial so this may not be the case.
| arcticbull wrote:
| Flight numbers get changed when airlines re-do their
| scheduling. It's still a fairly manual process as sometimes
| the numbers are symbolic.
|
| Either way, when they talk about re-using flight numbers on
| the same day, what they mean is they create multi-stop
| flights to use the same number for each segment instead.
|
| So you'll see flights like, hypothetically...
|
| > AA 1325 ORD-LGA
|
| > AA 1351 LGA-YUL
|
| > AA 1352 YUL-LGA
|
| > AA 1326 LGA-YUL
|
| Getting converted into a single flight number.
|
| > AA 1325 ORD-LGA-YUL-LGA-ORD
|
| Basically converting this to a flight from Chicago to Chicago
| via New York and Montreal nets them a 4:1 reduction in
| numbers used.
|
| You can still book each segment separately, and if they
| generally book the same plane, say some Envoy Air regional
| jet, for all four segments, there's little risk that
| irregular operations will lead to two planes in the air at
| the same time with the same number. Worst case they can give
| that one segment a new flight number for that day.
|
| They've been doing this a lot in the last few years,
| especially on regional flights, and especially in the
| northeast where there's a ton of short hops.
|
| [edit] If they want a bunch of their flight numbers back they
| can stop codesharing and switch back to relying on interline
| ticketing and sell the operating carriers flight number. I
| can't really think of anything good that's come of
| codesharing to individual passengers.
| lisper wrote:
| > Flight 1555 from ORD to BWI departs at 4PM today, and
| flight 1555 from ORD to BWI departs at 4:20PM tomorrow.
|
| Why do you find that remarkable? That's just the same flight
| departing at slightly different times on two different days.
| lazide wrote:
| Flight # of Theseus?
| madeofpalk wrote:
| > although that means they need for it to be flights that would
| never both be in the air at the same time
|
| It's interesting that this is called out, because there are
| frequently at multiple flights in the air with the same flight
| number
|
| QF1 / QF2 is now over 24 hours, and has daily flights. It seems
| pretty feasible to have the SIN-LHR leg be delayed just enough
| so there's two SIN-LHR QF1s in the air at the same time.
|
| Singapore Airlines has some 19 hour flights. Qantas hopes to
| have a 22 hour flight 'soon'. Very feasible that these can be
| delayed just long enough so there's two of the flights in the
| air at the same time.
| the_mitsuhiko wrote:
| I think you do not need 24 hour flights for that. Some flight
| numbers are used multiple times throughout the day. If one
| gets delayed too much, then two planes can be in the sky at
| the same time with the same flight number.
| Scoundreller wrote:
| It's gotta be a big YMMV thing. I wonder if US airlines
| might do that domestically only but not for international.
|
| Air Canada will renumber a daily flight if the delay goes
| past midnight (to avoid having two departures with the same
| number on the same day). I doubt it's just a courtesy, but
| an incompatibility with their (or enough airports'
| systems).
| the_gipsy wrote:
| Last call for passenger jll29 for flight seven dee eff eff
| eight two nine one, three eff eight nine, four zero four zero,
| bee eight see three, bee two zero zero seven six see zero dee
| dee ee ee.
| anoncow wrote:
| >Whenever I hear that any IDs could be "recycled", I make a
| mental note to replace the person making such a proposal from
| all teams that I am involved in.
|
| Mental note to not work for you.
| ViktorRay wrote:
| _Whenever I hear that any IDs could be "recycled", I make a
| mental note to replace the person making such a proposal from
| all teams that I am involved in._
|
| This sounds pretty messed up to me. Someone makes a suggestion
| or throws out an idea you don't like so you're gonna
| essentially cut them out of your professional life or even fire
| them? Am I reading this right?
| petsfed wrote:
| You're gonna hate the e.g. Southeast Alaska route names, where
| the plane arrives from one location, unloads some passengers,
| loads others, then takes off for another destination entirely
| (specifically Anchorage->Juneau->Petersburg-
| Wrangell->Ketchikan->Seattle), and yet it's the _same flight
| number_ the whole way.
|
| They've competing constraints here: they need all flights to be
| uniquely identified while in the air, but also all flight
| identifiers need to be easily expressed over audio. So, even
| switching to e.g. hexadecimal could be difficult, because "A"
| can sound like "8". So maybe we use phonetic alphabet for those
| digits?
|
| Oh but wait, this is to say nothing of the devices actually
| tasked with transmitting/receiving this info. If the software
| engineers correctly identified the risk here, then the flight
| numbers are being stored as two 16-bit integers inside the
| firmware, so there's plenty of headspace. But if not (say, they
| only gave 14 bits to the flight number, and 10 bits to the
| airline designator), then the firmware has to be updated. The
| FAA lists 648 air traffic control installations in the US,
| covering 19,000+ _American_ airports. For what are probably
| obvious reasons, the lions 's share of the equipment is not set
| up for firmware updates via a simple push mechanic, if its
| setup for remote update at all.
|
| All of this to say, I agree, its dumb, but when this stuff was
| invented, the prospect of almost 20,000 airports in the US (so,
| probably on the order of 100,000 globally) likely seemed
| impossible. Future-proofing has a physical cost, and at the
| time, it may have been literally impossible to calculate the
| true cost.
| sigwinch28 wrote:
| Reuse of identifiers seems to be a theme in aviation
| https://news.ycombinator.com/item?id=37401864
| burnte wrote:
| > Whenever I hear that any IDs could be "recycled", I make a
| mental note to replace the person making such a proposal from
| all teams that I am involved in.
|
| There's an EMR/EHR we use at my employer that reuses UUIDs. If
| an appointment is moved/rescheduled, the UUID is reused for
| that appointment meaning the UUID is no longer UU. It causes
| major issues with other apps that interact with the EMR/EHR, to
| the point we have to educate users to cancel and create new
| rather than rescheduling appointments.
| kelnos wrote:
| That seems... fine... to me? It's not a different
| appointment; the time has just been changed. It feels like
| that's a bug with the other apps: they are assuming that they
| can cache all metadata associated with an appointment and
| that nothing will ever change, but that's a bad assumption.
| pasc1878 wrote:
| Well that would depend on what the written specification of
| that id is.
|
| Is it the id of the appointment at that time or is it the
| id for the appoint meant.
|
| Seems like the originator chose the latter and the others
| the former.
| tyleo wrote:
| I work on a system where id reuse was necessary due to memory
| constraints. We were identifying hundreds of thousands of
| objects using GUIDs and referencing the GUID of course cost the
| whole 128-bits. All this data also had to be networked.
|
| We moved the system towards using arrays which are filled with
| object data and the index of the object in the array is now the
| id... the 32-bit ids were of course 4x smaller.
|
| All this being said, we do not claim the objects to be
| "globally unique".
|
| Edit: if I could go back in time though, I still might give
| this pattern consideration
| https://lucassardois.medium.com/generational-indices-guide-8...
| bongoman42 wrote:
| I'm currently working on some airline code. It is amazing how
| much legacy code written in TPF is there and how restrictive it
| is. A lot of stuff is designed for straight up screen scraping.
| fishywang wrote:
| I don't think that's even new for the big N us airlines. I
| noticed about 10 years ago that there were some united flight
| number used by not really related flights, or for both outbound
| and inbound for the same city pair.
| andix wrote:
| What would stop the airlines to use more than one airline code?
| For example for American Airlines not only to use flight numbers
| like AAxxxx but also ABxxxx. AB is assigned to Air Berlin, which
| went out of service in 2017.
|
| Edit: A1 seems to be unassigned, which might be even better, to
| not create confusions.
| alfalfasprout wrote:
| That's my hunch too (since you can basically forget anything
| like 5 digit numbers of alphanumeric due to old DBs that can't
| be migrated easily).
|
| Probably the issue is that lots of assumptions around AA
| exclusively being American Airlines is baked in somewhere. That
| said, it seems easier than any of the alternatives (and
| recycling seems excessively risky and confusing).
| wtcactus wrote:
| I get constantly baffled at the amount of technical debt that
| goes on in civil aviation.
|
| The fact that no one just overhauls the system with backward
| compatibility and sets a deadline for the migration, is just
| insane for me. All these specific problems are solved, and in
| production (in freight for instance) for more than 2 decades now.
| But aviation just goes on with their 70s system.
| pixl97 wrote:
| Trucks are perfectly fine with waiting outside the freight hub
| if the transportation management software goes down and loses
| track of everything. A plane in the air is a ticking time bomb
| that needs to get on the ground before the fuel runs out. Two
| trucks being just feet away from each other at speed is
| perfectly fine. Two planes being within half a mile of each
| other when they shouldn't be is a critical emergency.
|
| Problems in 2D space are amazingly forgiving compared to those
| that occur in 3D space. The caution civil aviation has is
| because of the history of flying that is written in blood.
| alexpotato wrote:
| Many years ago, I worked on a trading floor.
|
| The legacy trading system (X Windows/Solaris/C++ based) was
| originally written in a time where market volumes were low so you
| couldn't have more than 10,000 orders (due to a limit on the size
| of the order id field).
|
| As volumes increased in the late 2000's, there were days where we
| were in danger of running out of orders ids.
|
| The fix? The system generated order ids 7 days a week even if
| trading only happened 5 days so we "borrowed" order ids from
| Saturday.
| tremon wrote:
| Sounds like a great opportunity to limit the size of an airline
| and promote competition: each airline can't have more than 10,000
| registered flights.
| NoMoreNicksLeft wrote:
| I generally know better than to read the native comments on
| articles like this, but I've not really woken up yet. Are those
| merely stupid when they suggest using alphanumeric, or are they
| abominably stupid because the backend only allows numeric codes?
| willhackett wrote:
| Code-sharing is a headache for customers. Trying to find your
| flight on a rotating screen is frustrating, and having a
| different flight number on your ticket compared to the actual
| flight is just confusing. We should do away with code-share
| numbers and use the operating airline's flight number instead.
| yarrowy wrote:
| how about they help jumpstart the economy and hire engineers to
| fix the problem?
| itchyouch wrote:
| I wonder if they have enough 2 digit letters to expand their
| usages.
|
| Perhaps American Airlines could have both AA & AB, so they would
| then have 20k flight numbers to use?
| indus wrote:
| In 2010, Indian railways switched from a four-digit numbering
| system to five digits.
|
| They were running out of train numbers.
|
| Indian railways today operates 13,000 trains daily.
|
| There is a PDF that talks about the problem, the solution,
| exceptions, and a rollout plan.
|
| One fine day, IT systems seamlessly transitioned---took some time
| to wipe the old numbers from passengers memories.
| akpa1 wrote:
| Do you have a link to the PDF?
| Green-Man wrote:
| I looked up the nickname of the author of the commentary. Now I
| feel recursion is still running inside my brain
| josephcsible wrote:
| > assigning the same flight number to more than one flight a day
| (although that means they need for it to be flights that would
| never both be in the air at the same time, such as where the same
| plane is used and can't reasonably be substituted)
|
| I thought this was already common on a lot of airlines. For
| example, tomorrow, Southwest flight 1861 goes from MDW to DAL
| from 1:55pm to 4:10pm, then from DAL to SNA from 4:50pm to
| 5:55pm, then from SNA to PHX from 6:30pm to 7:50pm. I was on two
| legs of a similar flight a few years ago, and I didn't even have
| to get off the plane at Love Field.
| pixl97 wrote:
| One should note, this is why SW completely falls apart when
| mass weather delays or computer systems crashes occur. They
| have any number of 'serialized' components in their system that
| are efficient in optimal situations but degrade poorly.
| FerretFred wrote:
| It won't be a problem soon as airlines worldwide will obviously
| be scaling back flights due to climate change, right? ;)
|
| /s (just in case)
| todd8 wrote:
| Time for hexadecimal.
| lozf wrote:
| Using Hexadecimal instead gives over 6.5 times as many
| possibilities in the same 4 characters - should be more than
| adequate.
|
| I know airline systems have a lot of legacy code so it might be
| difficult, but at least logistically (having adequate space to
| print / display them), and for humans to deal with it's not too
| difficult.
| ASUfool wrote:
| Not sure if I'd want the flight number DEAD.
| laweijfmvo wrote:
| Just give each airline another prefix UA1234 -> UN1234.
| whalesalad wrote:
| IPv6 is the answer: now boarding to Salt Lake:
| DAL:1050:0:0:0:5:600:300c:326
| quijoteuniv wrote:
| Stupid here, but how hard is to change it to alphabumerical?
| jmpwat wrote:
| they're going to have to NAT them
| mise_en_place wrote:
| Part of the problem is codesharing, you have to use two flight
| numbers for the same flight. The whole practice is confusing and
| I don't think it should be allowed, except in the rarest of
| circumstances. The seat quality is also suspect at best, when
| you're not directly buying from the operating carrier.
| wooptoo wrote:
| They need NAT!
| surfingdino wrote:
| "Four digits ought to be enough for everybody!" ... looks down at
| his hands...
| deniz_tekalp wrote:
| if they re-use the flight number maybe they can add a letter
| suffix to it. e.g. 1555B?
| Am4TIfIsER0ppos wrote:
| That's easy: fork the airline. Or have you run out of 2 letters
| too?
| dangoodmanUT wrote:
| "Oh no"
|
| * adds a 5th digit
| _def wrote:
| ... to every codebase, flip display and whatelse not in the
| world
| franky47 wrote:
| I like how everyone is looking for technical solutions, where the
| trivial one is to reduce the number of flights.
|
| It's not like we're not in a climate crisis after all.
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