Messages in this thread |  | | | From | (Christoph Lameter) | | Subject | Re: Slow PPP - caused by duplicate packets? | | Date | 31 Mar 1996 07:59:49 -0800 |
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: > > It _looks_ like the other end is ignoring our first ACK, so it times out, : > > and then sends the packet again. And then we ACK it twice (that's normal : > > linux behaviour - there's the "normal" ACK, and then there is an extra : > > one that comes from the fact that the linux TCP code decides we'd better : > > ack again when we got a packet re-sent). : > > : > > Now, WHY is Solaris ignoring our first ACK? : > : > Is our first ack falling out of the cable, or not being sent or : > something like that. : > : I have been listening to this thread for a while now. I'm running basically : the same setup with no slow-downs seen from 1.3.57 through 1.3.80, which : I am now running. Could you post your exact configuration please? : This sounds like a timing problem at the Solaris. I have seen this kind : of problem over sdlc links before, where one side was always off building : a buffer when the ack came, and missed it, causing an unnecessary retry : of the buffer send. I have the same problem with 1.3.81 dialin to 1.3.57 and 1.3.81.... This must be a linux problem. We dont use Solaris or anything else.
: BTW, did I hear that this is an external modem? It is possible that the : handshaking problem is with your own modem (ie. the modem doesn't sent : the ack because it never received it due to being busy on another task) : and not between you and the Solaris. Have you tried other hosts? I am running an Internal modem here. I tested the serial driver with regular dialin and it works fine at high speeds etc. The problem ONLY exists on a PPP/SLIP link.
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