CUBE as SBC to Office 365

[ajones]

We are currently evaluating Office 365 in our organization and are looking to use Exchange UM in the cloud for VMs (we use it on prem right now).  The basic setup I'm attempting is below:

CUCM-----(SIP Trunk)-------->CUBE-----SIP(TLS/SRTP)------>Office 365

I have configured the CUBE to use the proper 3rd party certificates and the TLS is working normally.  However, when I call the VM Pilot (1922), the phone rings and then hangs up immediately.  It appears to be a codec issue, but its using G711ulaw all the way through.  I've attached my sanitized show run as well as the debugs for ccsip messaging.

[ADAM CRISP]

Hi Alan,

The call is failing since the CUBE can't provide Secure RTP.

The generation of SRTP is done on the PVDM DSP modules, so your ISR router needs to have PVDM resource available.

Assuming you have this, then you need to configure a secure media transcoder on the ISR router to transcode from RTP to SRTP. 

http://www.cisco.com/en/US/partner/docs/ios-xml/ios/voice/cube_proto/configuration/15-2mt/voi-srtp-rtp-int.html

Adam