[cisco-voip] sRTP and RTP in SIP Invite

[Mark Holloway]

I’ve got a non-Cisco SIP device sending SIP Invites to CUCM (SIP Trunk). The SDP from my device includes RTP and sRTP in the SIP Invite. Reading Cisco docs it looks like the way Cisco expects sRTP to work is the SIP Invite should only include sRTP assuming if the call should be encrypted.  If both RTP and sRTP are in the SDP, CUCM will always choose the first one in the list rather than the preferred type (sRTP in this example).  In my case RTP is being listed first then sRTP, therefore CUCM will never choose sRTP even though that is what I prefer.

Has anyone encountered this before and is there a way around it?  

Thanks,
Mark