Hi all, I recently installed traffic shaping on my ADSL line with a nominal upload rate of 1MBit. My Modem says it has an upload bitrate of 843 kbits. So I thought, to use a ceiling of 800kbit for the root qdisc is a good idea. But with that setting I only achieved upload rates of around 300kbits whereas I reached around 650 kbits without traffic shaping. Yesterday I played a little with the ceiling value and found that increasing it to 175kBps did the job. Could anybody please explain this strange behaviour? My shaping script looks as follows:
Philipp Leusmann wrote:> Hi all, > > I recently installed traffic shaping on my ADSL line with a nominal upload > rate of 1MBit. My Modem says it has an upload bitrate of 843 kbits. > So I thought, to use a ceiling of 800kbit for the root qdisc is a good idea. > But with that setting I only achieved upload rates of around 300kbits > whereas I reached around 650 kbits without traffic shaping. > Yesterday I played a little with the ceiling value and found that increasing > it to 175kBps did the job. > Could anybody please explain this strange behaviour? > > My shaping script looks as follows:I see nothing :-) DSL usually uses atm and the showtime rate of your modem is at this level. (FWIW 843kbit is not a valid DSL rate (multiple of 32kbit). You can patch (may be mainline eventually) kernel/tc to do atm rates in which case you can set egress rate close to showtime rate. Without this 80% or less will be needed (depends on traffic packet size). As for other wierdness - could be that htb/hfsc sometimes choose lame defaults (3/1 IIRC) for queue length on interfaces with low/0 default Q len - ppp/vlan/br etc. So add some qdiscs to leaf classes so you can choose your own lengths. Andy.