2006/4/7, Martin A. Brown <martin-lartc@xxxxxxxxxxxxxx>: > > Hi there Emanuele, > > I realize I'm jumping in a bit late on this item, but I don't quite > understand why HTB as below should not work for you. Have you tried > a configuration like the below? You must know your available > bandwidth for this trick to work, but the following configuration > approximates a PRIO qdisc, but gives you the benefit of shaping. > > class $parent, rate $MAX, ceil $MAX > | > +- class $voip, rate ( 0.95 * $MAX), ceil $MAX > | > +- class $other, rate ( 0.05 * $MAX), ceil $MAX > > Remember that all the shaping and prioritizing in the world will not > help you if you are not the bottleneck. Your shaping/prioritizing > device must be the choke point. I've already tried this way... with VoIP traffic this solution doesn't work very well, because data traffic tries to use as much bandwidth as possible, and it creates some jitter and delay on voice data... > While I don't have any direct experience with VoIP, I can imagine > that you might see an increased latency as a result of queuing delay > in your VoIP class. To limit latency induced by queuing delay, you > could create a child of the $voip class with bfifo or pfifo qdisc of > a specified depth/size. If, however, this is necessary, you may > simply need more bandwidth. don't need more bandwidth, I need that data bandwith is reduced! > And, as an attempt to answer your question above....perhaps you > could try fiddling with the quantum setting on a given class. When > a given class has exceeded its rate, it can only transmit quantum > bytes per dequeue opportunity. I tried changing quantum and r2q parameters of HTB, but I can't solve this problem... setting a low value of quantum results in decreasing real throughput, and it also introduces dependence on packet size... Another test I've done is to create only a prio qdisc (without HTB) and make the phisical layer slower than incoming traffic. It appears to be a problem of prio, because the same problem of queuing in high priority queue happens. Emanuele _______________________________________________ LARTC mailing list LARTC@xxxxxxxxxxxxxxx http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
