lkml.org 
[lkml]   [1996]   [Apr]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: PPP is slow (and so is TCP!) [with fixes]
Date
> send not send the next character until it gets the ack for the
> previous one. Since ACKs are delayed this really slows down
> the arrival of the response to interactively typed characters.
> Second, after I fixed the above problem I found that delayed ACKs
> where not being dealt with correctly. In particular we're
> violating RFC1122 in a couple of places:
>
> o It is required that an ACK packet that is delayed be delayed
> by no more than 0.5 seconds. The implementation can be forced
> to violate this easily. The problem is that every time new data
> arrives we reset the timeout for the ACK. An ACK can get delayed
> for as long as we continue to received data packets in order.

Sounds like we have/had another serious oversight too. BSD doesnt delay
acks on frames that are not mss sized (to avoid tripping nagle). We ought
to be doing the same. I hadnt realised the changes that got put in didnt do
that



\
 
 \ /
  Last update: 2005-03-22 13:37    [W:0.034 / U:0.160 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site