[e2e] Some questions about TCP.

rick jones perfgeek at mac.com
Tue Nov 24 13:55:29 PST 2009

On Nov 24, 2009, at 10:01 AM, David P. Reed wrote:

> On 11/24/2009 11:41 AM, rick jones wrote:
>> Since reordering is presumed rare, when three of these duplicate  
>> ACKs have been received, we can presume that three segments beyond  
>> the possibly lost segment were received and be statistically  
>> certain that segment was indeed lost.
> I may have gotten confused by the way this conversation has  
> wandered, but there is no statistical certainty  of loss here.    
> There are lots of ways that three duplicate ACKs can be sent, and  
> then received.  Every time the receiver receives a duplicate of a  
> previously accepted segment it will transmit another ACK with the  
> same content - there need be no "hole" and no segments to the  
> "right" of the hole.

I shouldn't have invoked statistics when recounting my understanding  
of the reasoning behind the fast retransmit heuristic :)

Wisdom teeth are impacted, people are affected by the effects of events

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