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

Fred Baker fred at cisco.com
Tue Jan 30 00:42:44 PST 2007


On Jan 30, 2007, at 12:01 AM, Baruch Even wrote:

> There are cases of asymmetric links that might cause trouble, but that
> will only serve to slow down the payload direction as well since  
> packets
> are released to the network only when acks come back, so a lost ack  
> will
> already slow down the rate of the payload, just not by cutting the  
> cwnd
> to half.

actually, one can argue that it speed the payload up, or that it  
causes it to burst. If I have octets 10000..20000 outstanding,  
receive an ack for 10000-11999, and drop one for 12000-13999, and now  
receive an ack indicating that my peer has received "through 15999",  
that looks to me like an ack for 12000-15999, and I should send a  
burst of that size.


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