Thanks Jim
I have attempted to balance the txgain and rxgain, perhaps to some success. The rxgain is at +8 and the txgain is at -15, have I gone too far with the -15? Should I go further? I don't think I should be echocancelwhenbridged , I tried and it seemed to make things worse. The sound quality is now a more of a reverb than an echo. I am down to 64 taps and echotraining is at 400. I have a 1.8 gig box I can spare, I will have to build this for Asterisk, and yes I am using a clean, minimal build, no x windows, database, ect. _____ From: Jim Van Meggelen [mailto:[EMAIL PROTECTED] Sent: Sunday, July 23, 2006 3:41 PM To: [email protected] Subject: RE: [on-asterisk] Echo on SIP to FXO I would say that you'd want echocancelwhenbridged=yes Set your echotraining to somewhere between 400 and 800. I might be wrong but I doubt that 1400 is going to do anything for you, other than delay dialing. Not sure how may taps you'd need; what is the tail on your echo (does it happen right away, like reverb, or after a half-second or more)? Anyhow, all that aside, let's forget all the echo settings for now and do some work with the levels on your lines. In your /usr/src/zaptel directory is a util called ztmonitor. Make a test call on one of the FXO lines and then run that utility. It's not exactly a carrier-grade application, but it's useful enough to give you a kind of VU meter that will allow you to visualize the levels on your zap channels. If you play with that app for a few minutes you'll get a feel for what it is doing. Not rocket science, but visually it does serve some pupose. The levels should hover kinda-sorta in the middle of each VU bar. This concept will make a lot more sense once you run the app. If the TX is too high (or too low, but I suspect the former), consider adjusting the txgain by a negative value of some sort. Try -3.0, for example. Restart asterisk and try again. Keep doing this until the level seems to sit right in the middle (or whatever you like) In the same vein, the rxgain can also be adjusted. Positive values will gain, negative values will attenuate. Again, your lines may be too hot so you will want to attenuate. You can do a lot of tweaking with the levels on the line, and this can often correct stubborn echo troubles, but ultimately it may be that a hardware echo-can solution is all that you can do. This will require you to replace your card with a product that can perform that task. The asterisk software echo can has it's limits. Which reminds me; that CPU might not be enough to give the echo can the power it needs. You are running a LOT of taps and a long training period. I'm thinking that might be a factor. Also, your system is running nice and clean, yes? No X Windowing system, no databases, no fancy GUIs, no apps like cpuspeed? That's a pretty minimal system to be running heavy echo cancellation, so be sure you are giving it a fighting chance. Good luck. P.S. I am running a pretty old TDM400, and I run calls through it all day long with no echo ever (I also have a 3GHz hyperthreaded CPU, which helps a fair bit). Having said that, I never put new systems into production using analog cards without a hardware echo can. The extra cost is worth it. Jim -- Jim Van Meggelen [EMAIL PROTECTED] http://www.oreillynet.com/pub/au/2177 "A child is the ultimate startup, and I have three. This makes me rich." Guy Kawasaki -- _____ From: Kevin [mailto:[EMAIL PROTECTED] Sent: July 23, 2006 3:01 PM To: [email protected] Subject: [on-asterisk] Echo on SIP to FXO I have a Digium TDM411p (one fxo and one fxs). On the fxs is an Siemens cordless. I also have a couple of Cisco 7960Gs that I have converted to SIP (firmware 3.7.5). The PC is a 933 with 512 mb. I am running fxotune for the TDM400. This is a 2.4 kernel and I am at Zaptel 1.2.7 and Asterisk 1.2.10 SIP to SIP good FXS to FXO good FXS to SIP good SIP to FXO ECHOooo I have been playing with the echocancel (now at 256 taps) and the echotraining (at 1400), echocancelwhenbridged is no. I have also switched to MARK2 ECHO CAN and added Aggressive suppressor. I would describe this echo as not quite good enough. Better than before 70 or 80 test calls, but I would like it a little better. How do I remove the last of the echo, or is it possible? Does anybody have clean SIP on a TDM400 Do I scrap the SIP phones? Is there a better echo cancel than Mark2? Kevin Vieyra [EMAIL PROTECTED] -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.394 / Virus Database: 268.10.3/395 - Release Date: 21/07/2006 -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.394 / Virus Database: 268.10.3/395 - Release Date: 21/07/2006
