Add SDP

sip-manipulation
        name                      addSdp
        description               add an entire SDP if one does 
                                  not exist
        mime-sdp-rule
                name                   addSdp
                msg-type               request
                methods                INVITE
                action                 add
                comparison-type        case-sensitive
                match-value
                new-value              “v=0\r\no=mhandley 
2890844526 2890842807 IN IP4 “+$LOCAL_IP+”\r\ns=SDP Seminar\r\ni=A 
Seminar on the session description protocol\r\nu=http: 
//www.cs.ucl.ac.uk/staff/M.Handley/sdp.03.ps\r\ne=mjh@isi.edu 
(Mark Handley)\r\nc=IN IP4 “+$LOCAL_IP+”\r\nt=2873397496 
2873404696\r\na=recvonly\r\nm=audio 49170 RTP/AVP 0\r\n”