On Mon, Oct 03, 2011 at 08:43:37AM -0700, Patrick J. Timlick wrote: > (PLUGers: I am answering Aaron's questions here, but the answers may be of > some general interest. Also, PLUGers like open(ness).)
Always good. It would be very sad if open technical discussion were to be discouraged because someone used it as an excuse for trolling or leeching. > On Wed, Sep 28, 2011 at 2:29 PM, Aaron Burt <aa...@bavariati.org> wrote: > > Echo cancellation can be a bear. Which PCI card? > > I forget, no time to take the skin off my Asterisk Box right now either, > sorry. NP. > > A little QOS goes a long way. Of course, bandwidth restriction at the > > gateway helps a lot. > > > I used a little QOS, to no avail. The worst problem is once in a while I > call someone and they can't hear me. Do you mean bandwidth restriction at > the gateway of everything else except VOIP? One-way audio is a different issue, usually due to NAT issues. Re: bandwidth restriction: It's a good idea to restrict overall bandwidth (including VoIP) at the gateway to keep from saturating your internet link. Even if you are using QoS (which doesn't really help much with UDP protocols like RTMP), your overall link latency goes waaaay up when the link gets saturated. The current buzzword for that problem is "bufferbloat". Saturated links lead to high latency and jitter, dropped packets, and overall call quality degradation. The easiest way to prevent it is to throttle bandwidth to a value JUST BELOW the maximum link bandwidth. So with a 1.5Mbps DSL link, limit it to ~1.4Mbps or so. (Try it out: push a lot of data through the link while pinging the nearest upstream gateway, and watch the ping times go from ~90ms to ~2000ms and back to ~90ms as you tune the throttling) > > I noticed your email address. You go to any IEEE meetings? > > > I haven't for a long time, but should. How about you? I go to the IAS and PES meetings. There's a great meeting tonight at OGI about "highly dynamic robot locomotion". Yes, they're teaching robots to run faster than us! The fools! :) _______________________________________________ PLUG mailing list PLUG@lists.pdxlinux.org http://lists.pdxlinux.org/mailman/listinfo/plug
