I am at the tail end of setting up my Call Manager Express. I am running CME version 9.0 on a 2911. I have the following issues still to resolve:
The phones (SIP) keep trying to register with the SIP Trunk Registrar. When I initially setup the trunk I had trouble with one way audio which was resolved by binding the dial peers to the WAN interface.
The phones keep jumping to not registered every few minutes and then will quickly register again. I'm assuming this is because they are trying to register with the SIP Trunk.
To switch to the SIP Trunk I added an ATA187 for Fax. No matter what I do I cannot get it to register.
I am using Exchange 2010 for Auto Attendant and Voicemail. I cannot get the MWI to work.
I have attached a sanitized config.