[HN Gopher] Understanding computer networks by analogy (2000)
___________________________________________________________________
Understanding computer networks by analogy (2000)
Author : asicsp
Score : 61 points
Date : 2023-03-10 12:45 UTC (10 hours ago)
(HTM) web link (memo.mx)
(TXT) w3m dump (memo.mx)
| orsenthil wrote:
| Good analogy. I had started to think ip-addresses as phone
| numbers, and it had started to make sense for me. Using Building,
| Floors, and providing analogies for interfaces, switches and
| routers were good.
| zamadatix wrote:
| I use a very similar analogy except it's either a meeting room
| with many people or an open floor that is the subnet. It helps
| explain BUM (Broadcast, Unknown Unicast, and Multicast) traffic
| in a more natural way e.g. ARP is you walking into a cube farm
| and shouting "is Jeff here?" and then he raises his hand so you
| can deliver the latest printouts directly to him without
| disturbing the others. In that case the individual is the IP, the
| cube floor is the subnet, and the higher level analogies are the
| same.
|
| The BAS relation for SDN is interesting. I've always avoided any
| analogies with SDN since different people have different ideas on
| what qualifies as SDN or what SDN is going to do but that's a
| really good choice given the rest of the analogies.
| zokier wrote:
| To me the thing that is difficult to wrap my head around is how
| congestion control, back pressure, and buffering at various
| levels work. It feels almost magical that somehow I can download
| stuff from various places and the bandwidth of different streams
| work out efficiently without much explicit coordination. And then
| there are things like bufferbloat.
| sophacles wrote:
| > To me the thing that is difficult to wrap my head around is
| how congestion control, back pressure, and buffering at various
| levels work.
|
| Snarky answer: that's because they don't.
|
| Attempts at humor aside: It really helps to understand a bit
| about queuing theory to wrap your head around these things.
| Each packet being an independent event has some unintuitive
| consequences. Each switch or router or etc (middlebox) in the
| path from one endpoint to the other adds the packet to a queue
| (which is what the buffers are), and that queue may be filled
| by other flows coming into the middlebox from different ports.
| suprjami wrote:
| All analogies eventually break down and end up doing more harm
| than good. Just teach the topics well. Part of knowing something
| is being able to communicate it effectively to others.
___________________________________________________________________
(page generated 2023-03-10 23:01 UTC)