Echo on SIP channel


Asterisk 1.2.17
Zaptel 1.2.16 / TDM400P (If that is relevant).

Echo on SIP / IAX2 Channel via 2 different ITSP’s.

Running Asterisk on P4 / 3.2Ghz / 512Mb / TDM400P

5 endpoints (Digium IAXy).

When calling outbound the called party heres their own voice in a strong echo approx half a second.

Ping to ITSP server is averaging 29ms

What I have tried:
2 Different ITSP’s
Both SIP and IAX2 from Asterisk to ITSP
Tried different CODECS (Ulaw / GSM / G729)

I have tried various combinations of following in [general] of sip.conf and iax.conf

echocancel= true / yes / 64 / 128 / 256
echotraining=800 / 1200 / 200
echocancelwhenbridged=yes / no

I have also tried adjusting volume on handset and tried different handset.

I believe HPEC won’t help as Digium site says it is for Zaptel hardware.

I am a bit stressed with this since the echo is so bad, if I can’t fix it I will surely have to take it out :frowning:

It might be worth mentioning that non of the changes I made had any affect at all. Same prominent half / one second delay experienced by called party. (their own voice).

Help will be REALLY appreciated!


Some additional info on this one.

There is a terrible echo when calling from 1 extension to the other within the same office. IAX ext to IAX ext.

It is the first time I have had to provide analogue extensions and used IAXy’s - I believe the IAXy’s could be the cause of this problem.

I have to get this fixed so I am thiking of trying some SIP ATA’s tommorow. What you think?

Comments appreciated.

just for the record, for the benefit of others in similar situation, I swapped out an IAXy with a Linksys Sipura 1001 today.

Echo gone 100%. Crystal clear audio on both internal SIP to SIP, and calls made via ITSP. I have ordered another 4.

Problem was not necessarily with IAXy but possibly a problem between IAXy and the analogue handset customer had chosen. (although I did try another handset which also echoed).

I notice the SP1001 has an option ‘echo cancellation on|off’ maybe that helps I don’t know but at least I can stop pulling my hair out now.