SDP Insertion for SIP ReINVITEs

The section explains SDP insertion for ReINVITEs, using a case where SIP session has been established with an initial INVITE containing SDP. In the diagram below, you can see the initial INVITE results in a negotiated media stream. But after the media stream is established, Endpoint B sends a ReINVITE without SDP to the Oracle® Enterprise Session Border Controller. In this case, the Oracle® Enterprise Session Border Controller inserts the negotiated media information from the initial INVITE as the ReINVITE's SDP offer. For subsequent ReINVITEs with no SDP, the Oracle® Enterprise Session Border Controller inserts the negotiated media information from the last successful negotiation as the ReINVITE's SDP offer. It then sends this ReINVITE with inserted SDP to the next hop signaling entity.