Hi,
Does anyone have a definitive answer as to what causes a transcoder to be invoked, rather than the call failing with a codec mismatch? Just thinking through some recent scenarios I find that it is not invoked on transfer to Unity Connection, if the offered codec is not supported on CUC the call fails. I came across that with G729b (not supported by CUC) and with G711a (not supported by default but can be added). On the other hand if a G711a call is put on hold, the transcoder is invoked for MOH. The difference would appear to be that for MOH CUCM knows it only supports G711u, whereas for external systems it neither knows nor can be told what codecs are supported.
I'm looking now at the CUCM to CUBE connections, ideally I'd like transcoders only inserted when needed, but I'm finding scenarios where a call fails instead, even though transcoding is available and configured in the MRGLs.
So it comes back to what triggers the insertion of the transcoder. For example would it do so in response to the codecs offered by the far end in an outbound slow start or delayed offer call?
Thanks, Tony S
