Subject: Re: [PATCH][RFC] Re: high latency with TCP connections

From: Rick Jones <[email-masked]>
Date: Mon, 18 Sep 2006 10:11:19 -0700

David Miller wrote:
> From: Rick Jones <[email-masked]>
> Date: Tue, 05 Sep 2006 10:55:16 -0700
> 
> 
>>Is this really necessary?  I thought that the problems with ABC were in 
>>trying to apply byte-based heuristics from the RFC(s) to a 
>>packet-oritented cwnd in the stack?
> 
> 
> This is receiver side, and helps a sender who does congestion
> control based upon packet counting like Linux does.   It really
> is less related to ABC than Alexey implies, we've always had
> this kind of problem as I mentioned in previous talks in the
> past on this issue.

For a connection receiving nothing but sub-MSS segments this is going to 
non-trivially increase the number of ACKs sent no?  I would expect an 
unpleasant increase in service demands on something like a "burst 
enabled" (./configure --enable-burst) netperf TCP_RR test:

netperf -t TCP_RR -H foo -- -b N   # N > 1

to increase as a result.   Pipelined HTTP would be like that, some NFS 
over TCP stuff too, maybe X traffic, other "transactional" workloads as 
well - maybe Tuxeudo.

rick jones