[asterisk-users] B410P and echo
Hi, Where can I find some tools, such as ztmonitor for zaptel devices, to adjust rxgain and txgain correctly on this card? I've some troubles with finding the optimal configuration for the echocancellator. Thanks in advance, Stefano Arata ___ --Bandwidth and Colocation Provided by http://www.api-digital.com-- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] b410p + fax (echo cancellation)
I really don't get it From several emails in this list archive, I had clearly understood that it is important to switch Echo Cancellation off for fax-channels, or faxing would not work properly. However, faxing (B410P ISDN bridged to TE410P PSTN) seems to work fine with EC at 256 taps on the B410P. I am confused; can anyone enlighten me? Thank you! Z. == Zoilo Gomez wrote: We have recently purchased a B410P Digium 4* ISDN-2 card with hardware EC. On the same server, I also have a regular Digium 4-channel PSTN-card (TDM410P ?), used to interface to some analog devices, a.o. 2 fax machines. For faxing, EC needs to be off (or so I understand from the archives). How can I switch EC off for an ISDN B-channel if a fax is coming in? Z. ___ --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 ___ --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
Re: [asterisk-users] b410p + fax (echo cancellation)
Zoilo Gomez wrote: I really don't get it From several emails in this list archive, I had clearly understood that it is important to switch Echo Cancellation off for fax-channels, or faxing would not work properly. However, faxing (B410P ISDN bridged to TE410P PSTN) seems to work fine with EC at 256 taps on the B410P. I am confused; can anyone enlighten me? Echo cancellation does not necessarily break faxing. However, depending upon how it is implemented it can. In general fax does not care about echo (as long as it is, indeed, more of a sidetone than an actual echo), and so it's generally good advice to tell people to disable echo cancellation on ATAs and other things when faxing is being used on them simply as a preventative measure. Lee. ___ --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
Re: [asterisk-users] b410p + fax (echo cancellation)
On Friday 23 February 2007 8:35 pm, Zoilo Gomez wrote: However, faxing (B410P ISDN bridged to TE410P PSTN) seems to work fine with EC at 256 taps on the B410P. Generally speaking all modems (this includes POS machines and faxes) emit a tone which echo cancellers recognize and disable themselves for that call. -A. ___ --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
Re: [asterisk-users] b410p + fax (echo cancellation)
Zoilo Gomez wrote: I really don't get it From several emails in this list archive, I had clearly understood that it is important to switch Echo Cancellation off for fax-channels, or faxing would not work properly. However, faxing (B410P ISDN bridged to TE410P PSTN) seems to work fine with EC at 256 taps on the B410P. I am confused; can anyone enlighten me? With EC on, modems might work, or they might not. If you have little or no echo, the EC actually does very little, so it won't significantly affect the one way at a time modems used for faxing. If you have a lot of echo, then having the EC switched on will degrade the modem signal. Things might still work, as a modem adapts itself to line conditions. You probably get more bit errors, but the fax will still get through. However, it doesn't take too much echo before the modems are pushed beyond the limits of what they can compensate for, and the receive side cannot extract the bit stream at all. So, the bottom line is it is not black and white, but EC off is more reliable. Regards, Steve ___ --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
[asterisk-users] b410p + fax (echo cancellation)
We have recently purchased a B410P Digium 4* ISDN-2 card with hardware EC. On the same server, I also have a regular Digium 4-channel PSTN-card (TDM410P ?), used to interface to some analog devices, a.o. 2 fax machines. For faxing, EC needs to be off (or so I understand from the archives). How can I switch EC off for an ISDN B-channel if a fax is coming in? Z. ___ --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
