Communication Manager behavior with SRTP Capability Negotiation

Last Updated : Oct 04, 2016 |

If SRTP Capability Negotiation is enabled, the capability negotiation call flow is as follows:

  • Communication Manager sends out INVITE with SDP Capability Negotiation.

  • Communication Manager accepts incoming INVITE with SDP Capability Negotiation.

If SRTP Capability Negotiation is disabled, the capability negotiation call flow is as follows:

  • Communication Manager sends out INVITE with null SDP on the Callee leg and negotiates based on the SRTP or RTP returned from remote. In case of SRTP, Communication Manager follows the SDES SRTP grammar.

  • Communication Manager does not accept any SDP capability proposed in the capability negotiation format. For example, if RTP is proposed in the regular SDP format and SRTP is proposed in the capability negotiation format, Communication Manager considers it as RTP. However, if SRTP is proposed in the regular SDP format and RTP is proposed in the capability negotiation format, Communication Manager considers it as SRTP.