Content-Type: application/sdp Content-Length: [len] v=0 o=user1 53655765 2353687637 IN IP[local_ip_type] [local_ip] s=- c=IN IP[media_ip_type] [media_ip] t=0 0 m=audio [media_port] RTP/AVP 0 a=rtpmap:0 PCMU/8000 ]]> ;tag=[pid]SIPpTag01[call_number] To: [$2] [last_Call-ID:] CSeq: 2 REFER Contact: Max-Forwards: 70 X-Call-Number: [call_number] Refer-To: Referred-By: Content-Length: 0 ]]> Content-Length: 0 ]]>