[Asterisk-Users] Two SIP servers communicating without IAX

[Philipp von Klitzing]

Hi!

> If I call from an MX250 phone to an Asterisk phone, the conversation is
> ok, but there is a noticeable delay in the voice stream.

You will probably want to start by analysing your ethernet network (using 
ping, traceroute, ethereal etc). You might also want to eliminate a 
switch in between and directly link the two systems to see if things 
improve.

> If I call from an Asterisk phone to an MX250 phone, I can talk FROM the
> MX250 phone TO the Asterisk phone, but not the other way around. In
> other words, the Asterisk phone will hear everything that is said from
> the MX250 phone, but if I say anything on the Asterisk phone the MX250
> phone never gets it.

Look at your codec configuration (disallow=all followed byallow= 
statements). Do a "SIP DEBUG" on the Asterisk CLI to learn more about the 
codec negotiation before/during a call. Finally check your phones VAD/ 
silence suppression settings, make sure those are turned off.

Cheers, Philipp