[Asterisk-Users] who changed the codec?

[kpfleming at starnetworks.us]

> Suddenly, 5126800422's legs are ulaw. What is interesting is that BOTH legs
> were changed. The leg from Cell->7206 was changed AND the leg from
> 7206->Asterisk->3035 was changed.

As previously discussed right here on this fancy list <G>, the Cisco
7940/7960 will not 3-way conference when using a low-bandwidth codec.
When you attempt to do so, they will attempt to reinvite the original
call to G.711, and if the SIP server allows that it will proceed. If
the server does not allow that (as ours doesn't), the conference will
fail.

In fact, in our configuration, when the user presses the Conference key
and tries to dial the 3rd party, it will fail because the phone will
only allow that call be completed using G.711, and our SIP peers are
not allowed to use anything but G.729.

As I mentioned to another poster a few days ago, Asterisk is not even
aware that this conference is happening (since it just sees the SIP
peer/user handling two simultaneous calls), so it cannot be held
responsible for making the codec change (nor can it do anything to
affect it).