Re: Why was hop by hop flow control eventually abandonded?

so most systems in the world do hop by hop as well as end to end
e.g. 
transportation systems  (traffic lights, stacks of planes, semaphores to
control trains entry/exit from track sections etc etc)
power systems (elec ant gas)
water systems (valves etc)
eco-systems (food chains/feast/famine etc)
political systems (you switch from feudal to democract, btut you still
have periodic elections - you switch from city states to countries,
but still have border and immigration/emigration controls...:)

so why do we think comms should be different?

in fact, I suggest we do some flow control inside nets - its called
traffic engineering and operates on aggregates - when we do 
multipath routing, we also select a modest number of routes (obviously
more than 1 but a lot less than actually would give connectivity or
even some additional capacity)....

so i think the design decision to throw out all hop by hop flow
control was probably an error (not a disastrous one: as many people
have pointed out, it simplified early router design a lot to be
completely stateless - but you don't need to keep per-5-tuple based
e2e state to do hop by hop flow control if its on aggregates, right?)

In missive <1374014873.23736.140661256474709.49B0CF90@webmail.messagingengine.c
om>, Mark Handley typed:

 >>It's before my time, but I'd always assumed it was also influenced by
 >>the NVP work, which would not have wanted hop-by-hop flow control.
 >>
 >>Mark
 >>
 >>On Tue, Jul 16, 2013, at 02:24 PM, Bob Braden wrote:
 >>> I believe that hop-by-hop flow control only works with per-flow state in 
 >>> the routers (see X.25 for example). Once the decision was made that the 
 >>> routers should be stateless, end-to-end flow control was the only 
 >>> option. That is what the end-to-end principle is all about.
 >>> 
 >>> Bob Braden
 >>> 

 cheers

   jon