More an echo algorithm question than a purely asterisk one... I have the following setup: Handset - PAP2 - Asterisk - SPA3000 - Telco And no matter what I do, I get echo on a call routed out via the PSTN when I talk into the handset, in the order of a hundred ms (my estimate, could be wildly inaccurate!). Echo will occur also when I have a handset plugged into the phone port on the SPA3000 (only when the call is routed via SIP of course), but I think it's more noticeable on the PAP2 due to the increased latency. The echo occurs even when I call an automated voice service or something, so I'm thinking that possibly there is a gross impedance mismatch on my side of the telco switch. I believe the following is happening (latency measures are guesses): Handset -(0ms)- PAP2 -(40ms)- Asterisk -(40ms)- SPA3000 -(0ms)- Telco Does an EC algorithm need a measurable delay to work? The EC would have to cope with an almost unmeasurably small echo delay (the delay only creeps in on the other side of the IP link. Is there another way I should be solving this problem, especially as I can keep Asterisk in the loop if I want to? Thanks James
On Thu, 2006-11-02 at 16:08 +1100, James Harper wrote:> More an echo algorithm question than a purely asterisk one... >Well, being the other side of the world my solution may not work for you. I had echo on my SPA3000, I was sure I'd selected the correct impedance for here in France, then one day I saw a setting "Global" in the dropdown for the FXO since then no one has complained about echo on any of the SPA3000 units I've got installed. Give it a try it might or might not help. -- Dave Cotton <dcotton@linuxautrement.com>
check the impedance for the fxo port. I bet it's set to 600. change it to 900 and see what happens James Harper wrote:> More an echo algorithm question than a purely asterisk one... > > I have the following setup: > > Handset - PAP2 - Asterisk - SPA3000 - Telco > > And no matter what I do, I get echo on a call routed out via the PSTN > when I talk into the handset, in the order of a hundred ms (my estimate, > could be wildly inaccurate!). Echo will occur also when I have a handset > plugged into the phone port on the SPA3000 (only when the call is routed > via SIP of course), but I think it's more noticeable on the PAP2 due to > the increased latency. > > The echo occurs even when I call an automated voice service or > something, so I'm thinking that possibly there is a gross impedance > mismatch on my side of the telco switch. I believe the following is > happening (latency measures are guesses): > > Handset -(0ms)- PAP2 -(40ms)- Asterisk -(40ms)- SPA3000 -(0ms)- Telco > > Does an EC algorithm need a measurable delay to work? The EC would have > to cope with an almost unmeasurably small echo delay (the delay only > creeps in on the other side of the IP link. Is there another way I > should be solving this problem, especially as I can keep Asterisk in the > loop if I want to? > > Thanks > > James > > _______________________________________________ > --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 >-- One day at a time, one second if that's what it takes