Stefanie Tellex
2007-Sep-07 13:48 UTC
Prioritizing VOIP traffic without sacrificing throughput
Hi, I would like to prioritize VOIP traffic when we use the phone, but other times not do traffic shaping at all. Right now I have my openwrt router set up with htb to do shaping. In order to get it to work well I had to set my upload and download speeds much lower than my line speed. With these settings, I get good VOIP reception even while surfing the net and doing a long download. However, even when I''m not using the phone, a long download is more than twice as slow than it is with shaping turned off. Is there some way to configure it to only do shaping when it detects VOIP packets, and otherwise not limit traffic? Thanks, Stefanie
Leigh Sharpe
2007-Sep-09 23:55 UTC
RE: Prioritizing VOIP traffic without sacrificing throughput
Can you post your configs? Essentially, in order to keep the latency as low as possible, you need to make sure that you never exceed the bandwidth of the upstream link. Whilst doing this, you are able to ensure that your VOIP performance is good. If you are not throttling your bandwidth, then just re-prioritising your VOIP traffic will not help. As soon as you do a large download, your link gets saturated and the latency goes up. Once that happens, even if your router is re-prioritising the VOIP traffic, it is still latent, which means that your phone performance will suffer. By setting the upload and download speeds lower than the line speed, you ensure that the line does not get latent, and then your re-prioritising is effective. Most people seem to be of the opinion that around 80% or so of the line speed is a good rule of thumb. -----Original Message----- From: lartc-bounces@mailman.ds9a.nl [mailto:lartc-bounces@mailman.ds9a.nl] On Behalf Of Stefanie Tellex Sent: Friday, 7 September 2007 11:49 PM To: lartc@mailman.ds9a.nl Subject: [LARTC] Prioritizing VOIP traffic without sacrificing throughput Hi, I would like to prioritize VOIP traffic when we use the phone, but other times not do traffic shaping at all. Right now I have my openwrt router set up with htb to do shaping. In order to get it to work well I had to set my upload and download speeds much lower than my line speed. With these settings, I get good VOIP reception even while surfing the net and doing a long download. However, even when I''m not using the phone, a long download is more than twice as slow than it is with shaping turned off. Is there some way to configure it to only do shaping when it detects VOIP packets, and otherwise not limit traffic? Thanks, Stefanie _______________________________________________ LARTC mailing list LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
Stefanie Tellex
2007-Sep-11 14:41 UTC
Re: Prioritizing VOIP traffic without sacrificing throughput
Hi, I''m not sure what the standard way to post configs is, but here is an attempt. I know that I have to limit my bandwidth in order to to traffic shaping. The problem is that in order to get good VOIP calls, I have to throttle the bandwidth by a lot. When shaping is turned on, my download speed drops by more than half. That''s fine when I''m actually making a phone call, but it is also much slower even when I''m not on the phone. So I was wondering if there was some way to turn on shaping only when I''m on the phone, and otherwise don''t do anything. Thanks, Stefanie root@openwrtrouter:~$ tc -d -s qdisc qdisc pfifo_fast 0: dev eth0 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 Sent 80516522 bytes 296966 pkts (dropped 0, overlimits 0) qdisc pfifo_fast 0: dev eth1 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 Sent 134572731 bytes 169287 pkts (dropped 0, overlimits 0) qdisc sfq 8004: dev vlan1 limit 128p quantum 1600b flows 128/1024 perturb 10sec Sent 303188 bytes 3819 pkts (dropped 0, overlimits 0) qdisc sfq 8003: dev vlan1 limit 128p quantum 1600b flows 128/1024 perturb 10sec Sent 11613498 bytes 25012 pkts (dropped 0, overlimits 0) qdisc sfq 8002: dev vlan1 limit 128p quantum 1600b flows 128/1024 perturb 10sec Sent 5074 bytes 21 pkts (dropped 0, overlimits 0) qdisc sfq 8001: dev vlan1 limit 128p quantum 1600b flows 128/1024 perturb 10sec Sent 16443879 bytes 143434 pkts (dropped 0, overlimits 0) qdisc htb 1: dev vlan1 r2q 1 default 40 direct_packets_stat 0 ver 3.17 Sent 28365639 bytes 172286 pkts (dropped 0, overlimits 11574) qdisc red 8008: dev imq0 limit 64000b min 8000b max 32000b ewma 4 Plog 21 Scell_log 11 Sent 6280529 bytes 14541 pkts (dropped 12, overlimits 12) marked 0 early 12 pdrop 0 other 0 qdisc red 8007: dev imq0 limit 64000b min 8000b max 32000b ewma 4 Plog 21 Scell_log 11 Sent 149830593 bytes 145595 pkts (dropped 1893, overlimits 1893) backlog 4476b 3p marked 0 early 1893 pdrop 0 other 0 qdisc red 8006: dev imq0 limit 64000b min 8000b max 32000b ewma 4 Plog 21 Scell_log 11 Sent 28810 bytes 157 pkts (dropped 0, overlimits 0) marked 0 early 0 pdrop 0 other 0 qdisc red 8005: dev imq0 limit 64000b min 8000b max 32000b ewma 4 Plog 21 Scell_log 11 Sent 6794403 bytes 24493 pkts (dropped 0, overlimits 0) marked 0 early 0 pdrop 0 other 0 qdisc htb 1: dev imq0 r2q 1 default 40 direct_packets_stat 0 ver 3.17 Sent 162934335 bytes 184786 pkts (dropped 1905, overlimits 224775) backlog 3p Leigh Sharpe wrote:> Can you post your configs? > Essentially, in order to keep the latency as low as possible, you need > to make sure that you never exceed the bandwidth of the upstream link. > Whilst doing this, you are able to ensure that your VOIP performance is > good. If you are not throttling your bandwidth, then just > re-prioritising your VOIP traffic will not help. As soon as you do a > large download, your link gets saturated and the latency goes up. Once > that happens, even if your router is re-prioritising the VOIP traffic, > it is still latent, which means that your phone performance will suffer. > By setting the upload and download speeds lower than the line speed, you > ensure that the line does not get latent, and then your re-prioritising > is effective. > Most people seem to be of the opinion that around 80% or so of the line > speed is a good rule of thumb. > > -----Original Message----- > From: lartc-bounces@mailman.ds9a.nl > [mailto:lartc-bounces@mailman.ds9a.nl] On Behalf Of Stefanie Tellex > Sent: Friday, 7 September 2007 11:49 PM > To: lartc@mailman.ds9a.nl > Subject: [LARTC] Prioritizing VOIP traffic without sacrificing > throughput > > Hi, > > I would like to prioritize VOIP traffic when we use the phone, but other > times not do traffic shaping at all. > > Right now I have my openwrt router set up with htb to do shaping. In > order to get it to work well I had to set my upload and download speeds > much lower than my line speed. With these settings, I get good VOIP > reception even while surfing the net and doing a long download. > However, even when I''m not using the phone, a long download is more than > twice as slow than it is with shaping turned off. > > Is there some way to configure it to only do shaping when it detects > VOIP packets, and otherwise not limit traffic? > > Thanks, > > Stefanie > _______________________________________________ > LARTC mailing list > LARTC@mailman.ds9a.nl > http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc_______________________________________________ LARTC mailing list LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc