Call Manager sip trunked to a Mitel 3300 Issue

[drsmith45]

Hello Everyone, we are connecting a 3300 to a Cisco Call Manager with sip trunking we are following the guidelines from the Mitel Interop and the Cisco document
everything is working good but when you call a Cisco extension from a Mitel phone , after the 8 rings when it is rerouting to the Unity voice mail you get a busy signal
immmediately ?
calling from a Cisco phone to a mitel phone you get that person's voice mail
any Ideas ?
Thanks

 

[leftyx]

Check what codec/codec's you use. I had the same issue with my Cisco to Avaya setup.

Once I changed to allow G711 I was able to connect to the voicemail.