[Asterisk-Users] Reproducible echo on IAX calls to -some- destinations.

[Ken D'Ambrosio]

I'm very, very confused.  Dialing out, through VoicePulse, with both gsm 
and ulaw CODECs, most of my calls are great.  However, calling my 
(non-Asterisk) voicemail at my job, and calling my cell phone both 
produce horrendous (~ 1/3-second delay) echo.  I've tried with different 
phones (Polycom and Grandstream), different IAX CODECs (as described, 
above), different network connections... but those two destinations are 
always horrible, and all my other victim..., errr, test numbers work 
just fine, all the time.

Any idea where to even start troubleshooting?

Thanks,

-Ken