How do you setup QOS to give traffic "A" absolute priority over traffic "B". Difficulty: traffic "A" is time-sensistive.
Posted on 2006-05-11
After reading the advanced routing HOWTO and experimenting, I've been unable to accomplish what I need: to give traffic A (VoIP traffic, in this case) absolute priority over traffic B (all other traffic). Each time I think I've got it, I find I can degrade the audio quality by flooding the uplink with traffic. Because "audio quality" is difficult to describe, I also left a ping going during the flood-test: it would jump randomly between 10ms to 100ms. Anyways.. here's a full list of what I have available:
* the router is a modern machine running Linux 2.4.32 (vanilla)
* CBQ, HTB, CSZ, HFSC and PRIO are available as modules
* connection is DSL, synched at 3000kbps down, 512kbps up
* "traffic A" packets are marked for expedited forwarding (rfc2598) for easy classification
HFSC looks like a promissing solution, but documentation is scarce.
Thanks, and good luck!