On Wed, Apr 30, 2008 at 5:43 PM, slashdev <slashdev@xxxxxxxxx> wrote: > > On Wed, Apr 30, 2008 at 5:27 PM, John Heffner <johnwheffner@xxxxxxxxx> wrote: > > > > On Wed, Apr 30, 2008 at 5:13 PM, slashdev <slashdev@xxxxxxxxx> wrote: > > > > > > On Wed, Apr 30, 2008 at 4:34 PM, John Heffner <johnwheffner@xxxxxxxxx> wrote: > > > > > > > On Wed, Apr 30, 2008 at 2:45 PM, slashdev <slashdev@xxxxxxxxx> wrote: > > > > > > > i can provide the tcpdump trace. but that too looks ok. i.e. window > > > > > scale is set to > > > > > healthy "10" and the receiver does endup opening large window. but i > > > > > may be missing > > > > > something. > > > > > > > > > > if you need any other information please do ask. > > > > > > > > > > i am bit puzzled at the moment :-) > > > > > > > > Linux should easily be able to support this "out of the box" these > > > > days. Can you post the binary tcpdump somewhere? > > > > > > http://slashdev.googlepages.com/traces/ > > > > > > i've added traces for 20ms rtt and normal lan rtt (aka 0ms rtt :-) > > > let me know if you have trouble accessing them or want any more > > > information. > > > > > > thanks for your help > > > > Both traces show lots of packet loss -- enough to cause an equilibrium > > cwnd of less than 100 KB. With a short RTT, this window is adequate > > to fill a 100 Mbps pipe, but with even a 20 ms RTT, it's hurting you. > > I'm not sure where the packet loss is coming from. Possibly an > > overloaded switch or bad cable? > > thanks for the insight. will take a look at my setup and see why that > should happen. will report back once i am done fixing things at my > end. got rid of the 100Mbps vlan. and connected the GigE's back-2-back using cross-over cable and with 20ms RTT i am able to fill the pipe nicely. getting ~900Mbps consistently :-) so it was the packet drop/loss at the switch ports. thanks a lot for your help :-) -- To unsubscribe from this list: send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
