Messages in this thread | | | From | Arthur Kelly <> | Subject | Poor PPP performance and txqueuelen | Date | Thu, 06 Jan 2000 18:21:38 -0500 |
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From the archives:
>> If not, wouldn't it be better to keep txquueuelen high and >> just grin and bear the latency for interactive use? > > No you want it smaller, this makes packet loss feedback happen much > more quickly, and thus TCP's heuristics respond to the situation faster. > > David S. Miller
That does not work well here. And it seems to contradict the ethernet default of 100 for txqueuelen.
I have a 2.2.14aa1 box routing between ethernet and dialup PPP interfaces. With the default PPP txqueuelen of 10, or if I set the PPP txqueuelen to a smaller value such as 3, I get dropped packets and poor FTP performance thru the Linux router.
But if I set Linux PPP txqueuelen to 30 or more, there are no dropped packets and FTP performance thru the Linux router is perfect.
In ppp.c, the default value for receive queue length is 32. In my local ppp.c, I've also changed the default transmit queue length to 32, and it works much better now.
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