On Monday 24 November 2003 7:35 am, Defekt wrote: > Hi, > > I'm using traffic shaping on my home 1.5M/256K ADSL connection. The > problem I'm running into is even when I'm shaping upload traffic (web > server/p2p etc...) I run into latency issues with online gaming. This is > of course due to the 256Kb upload and the 1492 MTU (PPPoE) which means a > single large packet will take up to 40ms to transfer. > > What I would like to do is reduce the MSS for low priority traffic using > ipchains based on a fwmark value. Is it possible to do this? > > Appreciate any other suggestions to solve this problem.
One thing to consider - assuming things are the same in your country as mine, is that DSL modems are atm devices an send whole 53 byte cells. So MTU = x+1 may send 53 bytes more than MTU = x, so choose carefully. I can't tell you exactly how to see what is right for you as I use pppoa, I think the overhead on pppoe is either 32 or 40 bytes, so you would find an MTU (MSS+40) add say 32 then divide by 48 (as each 53 byte cell carries 48 data) and change MTU until you get a whole number. If you can get your modem to give you a cell count you could test what the correct pppoe overhead is with ping -s x you could change x until the cell counter varied by 1 between x and x+1. If the overhead is 32 then ping -s 36 should send 2 cells (36 data + 8 ICMP + 20 IP +32 PPP = 96) & 37 three, s = 28 for two cells / 29 for three if it's 40. Andy. Andy. _______________________________________________ LARTC mailing list / [EMAIL PROTECTED] http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
