From: ;tag=[pid] Call-ID: [call_id] CSeq: [cseq] SUBSCRIBE Max-Forwards: 70 Event: presence Accept: application/pidf+xml Contact: Expires: 30 Content-Length: 0 ]]> ;tag=[pid] To: [peer_tag_param] Call-ID: [call_id] CSeq: [cseq] ACK Contact: Max-Forwards: 70 Content-Length: 0 ]]> From: ;tag=[pid] Call-ID: [call_id] CSeq: [cseq] SUBSCRIBE Max-Forwards: 70 [field2 file="callee.csv" line=1] Event: presence Accept: application/pidf+xml Contact: Expires: 30 Content-Length: 0 ]]> Content-Length: [len] ]]> From: ;tag=[pid] Call-ID: [call_id] CSeq: [cseq] SUBSCRIBE Max-Forwards: 70 Event: presence Accept: application/pidf+xml Contact: Expires: 0 Content-Length: 0 ]]> ;tag=[pid] To: [peer_tag_param] Call-ID: [call_id] CSeq: [cseq] ACK Contact: Max-Forwards: 70 Content-Length: 0 ]]> From: ;tag=[pid] Call-ID: [call_id] CSeq: [cseq] SUBSCRIBE Max-Forwards: 70 [field2 file="callee.csv" line=1] Event: presence Accept: application/pidf+xml Contact: Expires: 30 Content-Length: 0 ]]> Content-Length: [len] ]]>