[e2e] Stupid Question: Why are missing ACKs not considered as indicator for congestion?

Fred Baker fred at cisco.com
Wed Jan 31 23:32:41 PST 2007


yes, there are cases in which it means congestion in a radio circuit.  
My point is that there are cases in which it means nothing of the kind.

On Jan 31, 2007, at 2:55 PM, Armando L. Caro, Jr. wrote:

> Fred Baker wrote:
>> and in any event, I can think of many networks in which loss is an
>> indicator of nothing more than loss. Just say "radio"...
>
> That might not always be true. For simplicity, let's assume a single
> wireless link in the end-to-end path. If that link does L2
> retransmissions, loss on the radio channel will build up a queue at  
> L2.
> Now if the endpoints are seeing loss at L4, then that means the  
> loss was
> so bad that multiple L2 retransmissions were unsuccessful... which
> implies a larger queue. Thus, the sender should back off, just as it
> would if it experienced a loss on a wired network.
>
> -- 
> Armando


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