Messages in this thread | | | From | Alan Cox <> | Subject | Re: PPP is slow (and so is TCP!) [with fixes] | Date | Fri, 12 Apr 1996 16:02:56 +0100 (BST) |
| |
> 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
| |