McDewey

Incoming (to Unified CM) Outgoing (from Unified CM) Variable Message Lines Unified CM- generated string from the initial INVITE Endpoint-generated string from the initial INVITE string Call-ID: string Called Party Number Called Party Number userpart Contact:<sip:userpart@ip:port > Endpoint IP address Unified CM IP address ip Endpoint port Unified CM port port Sequence number from initial INVITE Sequence number from initial INVITE number Cseq: number INVITE None 0 and variable local-access-level Confidential-Access-Level: local-access-level SEMI reflected-access-level [SEMI access-display] None 0 and variable reflected-access-level None PENDING Access-display Endpoint SDP Unified CM SDP sdp SDP [sdp] 183 Session Progress The 183 message establishes early media. Unified CM will include SDP in a 183 message that is sent to an endpoint. The Remote-Party-ID header may have changed as well. Otherwise, a 183 carries the same values as a 180. 2xx Most 2XX values match the 180 message; 200 carries SDP. Also, the Remote-Party-ID may have changed after a 18x message was sent. Note Table 15: 2XX Message Fields, on page 22 provides the fields of 2xx SIP Response message. Table 15: 2XX Message Fields Incoming (to Unified CM) Outgoing (from Unified CM) Variable Message Lines SIP/2.0 200 OK SIP Line Messaging Guide (Standard Edition) for Cisco Unified Communications Manager 22 SIP Standard Line Interface 183 Session Progress