I have a 3745 configurad as an IP to IP gateway. I have a SIP trunk with G711ulaw to a Call Manager(5). There is another SIP trunk with GSM codec configured to another device. I can see that the transcoding does not kick in between G711 and GSM codec. For testing sake I tried to configure G729 to the second device and it works fine but not with GSM.
Does anybody have any suggestions/experience/information on this? Please let me know if you need more information aboout the configuration etc.
Thanks in advance for the help.