Messages in this thread | | | Date | Tue, 16 Apr 1996 16:46:51 -0400 (EDT) | From | Jauder Ho <> | Subject | Re: 1.3.89+Solaris+PPP - still lots of extra packets |
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I have a copy of tcpdump that can look at PPP :)
On Tue, 16 Apr 1996 cs95rro@brunel.ac.uk wrote:
> -----BEGIN PGP SIGNED MESSAGE----- > > > David Monro <davidm@gh.cs.usyd.edu.au> writes: > > >well, I have upgraded to 1.3.89, and I am still having ppp problems. > > >Interactive response to our Solaris server has improved - I no longer > > >get massive delays when attmepting to type-ahead into a shell. However, > > >I still have the duplicate packets problem with paging text files on > > >large xterms, and ftp transfers on a 68K (gzipped so no modem > > >compressions) file run at 240cps on a 14.4k modem. Below are the dumps > > >from both ends of the link for typing df on our server, which produces > > >85 lines of output. This time I have managed to include time stamps and > > >packet IDs at both ends. > > > > > It seems to me that SUNOS is choosing to retransmit packets much > > to early. Say a 1460 byte packet gets injected into the network by > > staff at time T, which then makes its way to your machine. > > Just counding transmission time over the modem I'd expect there to > > be a 1 second delay between the time staff sends the packet and the > > linux box can see it and ACK it. If the linux box waits another 1/2 > > second to send the ACK (which is about what we are doing now), > > then sends it over the modem, you'd expected pretty much what > > you are seeing for the round trip delay on the ACK. > > Looking at staff's output log, it starts the first resend 1/2 second > > after the first packet is sent. There is no way that fuzzbox can > > even have the packet yet, never mind have responded. > > I've had this problem, going via a Zylogics PPP box, on all versions of the > kernel I've used. (1.2.1, 1.2.13, 1.3.[lots]) I've not gone as far as packet > dumps (Mainly because tcpdump doesn't work on PPP and I haven't got time to > do it any other way) but it seems to me as if SunOS (Both 4 and 5) is overdoing > the source quench a bit. I generally get around 400cps on a good day (At 14.4k) > but for much of the time the transfer goes at full speed but then the CS drops > briefly and it waits for up to 30s. I hacked together a bit of C to spoon-feed > ftp data to the Linux box at 1.2k and it seems to work. > > Hope this helps. > > * cs95rro@brunel.ac.uk ryan@bcs.org.uk * Ryan Richard O'Connell * > * http://www.brunel.ac.uk:8080/~cs95rro * Finger: cs95rro@molnir.brunel.ac.uk * > The modern idiot is here and plain to see. > > -----BEGIN PGP SIGNATURE----- > Version: 2.6.i > > iQCVAgUBMXNrqHaLBcMKBcNNAQHRPAP8D4UdnT/olVLdiPTbPpcd9TmydmRKkRKt > EtYC/gSgoG+zS0DBKx5kQwYDaY3RnSK/zaagmavKExXULCKEJ4x4sHmKBWivcCH9 > 00e0z90GM5z+y7X/Z3xKJRhk1GyBfX3iDBUhA8cZ+bUnmSvC8zOQvBWuyT1nx0mq > K/wJkxSL0Ts= > =l2Bt > -----END PGP SIGNATURE----- > >
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