> Nice response. > > I just wanted to let you know that we do provide a tool to debug echo. > > We send a unit impulse and record the Finite Impulse Response (FIR) so it > can be plotted and analyzed. The code that does this is the release at > ftp.sangoma.com/linux/custom/2.3.4. Instructions on using it are in the wiki > in http://sangoma.editme.com/wanpipe-linux-asterisk-debugging.
Excellent, I'll give it a try. I'd love to see some tools that would help those that are not necessarily familiar with the issues. > Although the code is wanpipe, all the interaction is at the zaptel level, so > I am pretty sure it will work on Digium or other cards as well. > > Just being able to see what the echo looks like on a troublesome line gives > quite a lot of info. You can see if the echo is delayed, or markedly > non-linear. > > The FIR plots look like the ones in > http://www.linuxjournal.com/article/8424. > > BTW, a small correction: The "echocancel=128" defines how large of an echo > canceller to use in taps (1/8 milliseconds) not milliseconds. echocancel=128 > gives you a 128 tap (16ms) tail. Telco echo cancellers give a full 128ms = > 1024 taps. Ops, that's what I get for slamming a few beers while doing email. ;) I'd really love to contribute to the cause by documenting many of the pstn interface issues, but adequate tools to help the less knowledgable assess the environment tends to be a shortcoming. Rich _______________________________________________ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
