[HN Gopher] Build an SMS Forwarder with Raspberry Pi Zero W and ...
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Build an SMS Forwarder with Raspberry Pi Zero W and Waveshare
SIM7000E Hat
Author : mtrcn
Score : 106 points
Date : 2021-02-21 15:07 UTC (7 hours ago)
(HTM) web link (mete.dev)
(TXT) w3m dump (mete.dev)
| toomuchtodo wrote:
| When would you use this SMS gateway versus something like Twilio,
| Plivo, or Bandwidth.com terminating a DID for SMS service?
| jpollock wrote:
| When you want to have telemetry from somewhere without access
| to a wifi network.
|
| The last I looked, SMS was also cheaper and lower power than
| mobile data.
| tyingq wrote:
| I imagine they mean this specific use case where you need ip
| connectivity to Telegram anyway. If it were bridging to
| something local, it would make more sense.
| ComputerGuru wrote:
| The problem is that fixed part of most plans' pricing make
| the cost prohibitive, not the pay-as-you-go component (eg the
| cost of a sim and phone number).
|
| We were able to use a LoRa-like layer to forward to a base
| station that then uses a VoIP provider to do the brunt of the
| communication work.
| pjmlp wrote:
| I hardly use more than a couple hundred from my 5 000
| monthly budget to external networks, on the same network
| they are free.
| toomuchtodo wrote:
| True, but that's using SMS for telemetry (totally valid for
| use cases where power or connectivity are challenges) or
| remote control, not brokering SMS between another medium;
| this use case is forwarding SMS messages to Telegram. Maybe
| if you had a SIM for a geography that wasn't supported by a
| VoIP provider for programmatic access?
| jpollock wrote:
| Think of this as much about being a learning exercise as
| anything else. The project doesn't need to stand on it's
| own - the creator gets to learn something about both sides.
|
| It's like seeing that M.2 is PCI-E, and wondering if they
| can plug a regular video card into it. :)
|
| Although for this project, I can construct systems in my
| head where this would be useful, centered around non-US
| mobile plans which are "calling party pays", with free on-
| net SMS. The US is "bill and keep", which makes sending SMS
| off-net largely the same as on-net from the carrier's point
| of view.
|
| In "calling party pays", having a device on the same
| network as the controlled device is about avoiding per-SMS
| charges.
|
| Author is in the UK, and UK is CPP.
|
| https://www.researchgate.net/publication/227426633_Mobile_t
| e...
| techsupporter wrote:
| Lots of businesses really, _really_ want a mobile number from
| me for some reason, don't accept VoIP numbers, and I don't want
| to give them my real mobile number.
|
| So instead I have a stack of SIM cards plugged into GSM USB
| sticks (like this mostly is) and get the inbound messages sent
| to me via Pushover notification.
| ta1234567890 wrote:
| Do you have a recommendation for gsm usb sticks? Where do you
| get them?
|
| Do you use just one SIM card at a time, or do you have a usb
| stick that can hold (and operate) multiple SIM cards
| simultaneously?
| techsupporter wrote:
| I look for them on eBay but I don't have any current
| recommendations. In fact, I'm digging around for LTE
| replacements at the moment since T-Mobile is ending their
| GSM-only service rather soon.
|
| I have a few USB sticks plugged into a powered USB hub and
| Gammu watches all of them for inbound messages.
| jandrese wrote:
| Do you have dozens of phone bills to pay every month?
| techsupporter wrote:
| robotmay who also replied to you is correct for what I do,
| I have multiple prepaid US SIMs with PAYGO rate plans. It's
| trivial to get many of these and register them in bulk to
| get "real" mobile numbers.
|
| (This is why I laugh and laugh at people who insist that
| VoIP numbers are more "fraudulent" because of whatever.
| Right now, breaking no rules whatsoever, I can get a
| hundred mobile numbers that any service will accept, and
| they'll go for a year without needing any more money. Stop
| using phone numbers as identity verifiers, people. All
| you're doing is making it harder for the people who aren't
| technically savvy and accomplishing nothing to prevent
| actual fraud.)
| mindslight wrote:
| It's been a while since I looked, but the cheapest US
| paygo plans are still at least $3/mo (eg H2O wireless),
| and probably double that if you want more convenient
| billing. Have you found something better, or are you
| deriving that much utility from scaling to many devices
| or what? I'd think if the goal is signing up a bunch of
| accounts, one would be content with a single plan or
| maybe two, and just periodically swapping their phone
| numbers.
|
| It seems like it would be easy enough to change your
| setup to hide your actual location by locating the
| gateway elsewhere and backhauling with its own IP
| connection.
|
| BTW are there any standard interoperable formats for
| transmitting/presenting/archiving text messages, akin to
| Maildir for email or SIP for voice? If not, maybe Maildir
| is the right answer.
| bquest2 wrote:
| With all those sims, you still have a RSSI from physical
| cell phone tower(s), so its still serving its purpose for
| fraud prevention
| techsupporter wrote:
| How so? None of the fraud prevention APIs I've seen tell
| you if a given number is connected to a base station,
| only whether it's theoretically GSM, landline, VoIP, or
| something else. With the ability to tunnel LTE over an
| unstructured Internet connection ("wifi calling,") I
| don't have to be within range of a single US-based base
| station to "appear" like I am in the US to the mobile
| network.
|
| And everyone tells me that only accepting "real" mobile
| phone numbers means they're just piggybacking on the
| identity checks that mobile carriers do. Which, if true,
| I'd like to introduce you to Constable George Crabtree
| and his nineteen perfectly valid mobile numbers, all of
| them with his name in the CNAM field.
|
| All this does is prevent someone who's not tech savvy and
| who might be trying to save a bit of cash by using a
| Republic Wireless or TextNow or some other "free calls
| and texts!" service from fully participating in this new
| app-based reality we've constructed. Someone who actually
| wants to commit fraud will step right over these dumb
| speed humps and do whatever they like.
|
| I'm not saying don't do fraud detection, I'm saying don't
| do fraud detection that is so _screamingly trivial_ to
| bypass.
| simfree wrote:
| You might check out yoursecretnumber.com as their phone
| numbers show up as Cellular/PCS rather than landline.
|
| That being said short code support is middling, not quite
| as good as VoIP numbers that use Bandwidth.com (Google
| Voice uses them) or Onvoy.
| robotmay wrote:
| In the UK you can get a SIM for free from most networks as
| pay-as-you-go (i.e. you add credit to it instead of getting
| a monthly bill). With most of those you can happily receive
| messages on it without ever spending a penny.
| Jnr wrote:
| I use gammu-smsd and forward it to iOS using Pushover.
|
| For the serial AT modem I use random Huawei LTE USB stick that I
| bought for 15 EUR years ago.
|
| It was so cheap because it was provider locked, but there are
| keygens floating around internet that allow unlocking it to work
| on any network.
| [deleted]
| gsich wrote:
| Nice I guess?
|
| The hat itself is somewhat expensive (for only GSM), especially
| compares to LTE USB sticks which can do the same (and more). But
| of course not as compact and nice looking.
| lifty wrote:
| Does anyone know if you could you this combo to creat some kind
| of VoIP gateway that could forward calls to an app on an iPhone
| over the Internet?
| gsich wrote:
| There is something for Asterisk called chan_dongle.
|
| Then you can use any SIP client on your iPhone to connect to
| that Asterisk and make/recieve calls.
| 8K832d7tNmiQ wrote:
| You could probably develop one if you want. This is exactly
| what ride-hailing app Grab did in their app to make a call
| without exposing their phone numbers by forwarding calls to
| their server instead.
| _joel wrote:
| I'm pretty certain they wouldn't have used a raspberry pi for
| that
| shadycuz wrote:
| I'm not sure I understand. Does this thing do a man in the
| middle. Do you have to configure your phone to use it?
| akx wrote:
| It has a separate SIM card.
| keyme wrote:
| Why isn't there something that turns a rooted Android phone into
| a VOIP <-> Cell network gateway? Something that allows incoming
| calls to be forwarded to SIP, and vice versa?
|
| I haven't found something like that.
| gsich wrote:
| Not possible with most devices. I wanted something similar, no
| result. Seemed like a hardware restriction that phone calls go
| to either the speaker or Bluetooth.
| naivedevops wrote:
| Maybe because nobody had a strong enough use case to feel
| compelled to implement it. There are very cheap GSM to SIP
| gateways, that are way less expensive than a mobile phone.
| Teever wrote:
| Do you have any links for those? I can't imagine them being
| much cheaper than a free used smartphone that many people
| have lying around or the price of a used phone from a
| pawnshop or ebay -- $50.
| naivedevops wrote:
| Maybe not as cheap as an used phone, but close:
| https://a.aliexpress.com/_mK1XuTt
| [deleted]
| danielschonfeld wrote:
| Can someone please explain to me the appeal of telegram (as
| opposed to signal)? Maybe I don't understand something or am too
| old but how is it a safe haven compared to WhatsApp in the wake
| of the WhatsApp debecle. I just fail to understand.
| bayesianbot wrote:
| The APIs for bot programming for telegram are great - good
| documentation, stable, lots of options/libraries for different
| languages, and possible to do much more complex bots than other
| messaging platforms.
| seniorivn wrote:
| telegram is not secure, but it has secure secret chats feature
| it works, but nobody uses telegram for it's secret chats
| telegram is superior in 2 ways, ui/ux polishness and having an
| open api and native open source clients for all platforms the
| only potential competitior in that regard is matrix, but it's
| not there yet
| keyme wrote:
| It feels to me that Telegram is the closest thing to old school
| IRC that we "have"* right now. You can have public/private
| channels, you don't see other peoples phone numbers for no
| reason (you see their chosen nicks), you have bots, broadcasts
| and more.
|
| * That has any reach beyond the people who would scoff at this
| sentence.
| lofi_lory wrote:
| Telegram is not at all secure compared to Signal (in theory).
| However it has an awesome UI and lots of nice features (most of
| which are lost using secret chats).
|
| For the longest time these were exclusive features to telegram
| compared to Signal:
|
| * Delete messages at other party ("undo"), critical for
| deleting accidentally sent nudes. * Username only communication
| * Stickers (silly, but well kinda fun) * Bots (very easy to
| make your computer talk to your phone or a group this way) *
| link preview * Self messages as easy link/file sharing between
| devices. Super useful.
|
| Signal is slowly catching up, but it's so buggy at times, I am
| starting to really hate it/distrust it (I also dislike MM's
| personality/opinions). Matrix seems to move at a better pace,
| with more useful features already (e.g edit, markdown, some fun
| things). I am happy to get rid of telegram for Matrix. One
| feature better then the other already: resync of lost messages
| from the distributed network and no reliance on telephone
| numbers as UID.
| solstice wrote:
| The "note to self" has been there since I started using
| signal I think three years ago. Stickers are available since
| one and a half years, even though discovery could be better.
| Things have improved a lot in the last 2 years and I haven't
| encountered any breaking bugs.
|
| Edit: and now with the New Groups you can send people a group
| link so that they can add themselves. Haven't tried that out
| yet but that seems pretty cool
| z92 wrote:
| If you can't purchase the GNSS HAT, use an old Android phone and
| install Termux on it. Then run some bash scripts on the phone
| that will do the job.
|
| The phone will communicate with your network over wifi, and
| replaces both the Raspberry PI and the HAT.
| cromka wrote:
| I wonder if anyone tried running virtualized Android with an
| eSIM with VoWiFi? This way you could completely give up the
| need of having any hardware at all.
| newhouseb wrote:
| Also important to note that the Android approach is more likely
| to continue to work. In many places (certainly Manhattan, where
| I am), everything but LTE (and I gues 5G) has long been turned
| off such that GSM/Edge/UMTS/etc no longer work.
| efazati wrote:
| For solving a problem always there are millions of ways..
| theodric wrote:
| It's likely that this one is cheaper and more accessible to
| many, many people, including those in developing countries,
| since it doesn't rely on sourcing quasi-obscure hardware like
| the HAT
| pjmlp wrote:
| Back in the day we use to call such devices gateways.
| flemhans wrote:
| They would be hooked up to a Nokia 6110 with a serial data
| cable and use Gammu :D
|
| Edit: I just noticed that Gammu is still a thing and even used
| in this article.
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