or TPs," with the aim of checking the mandatory requirements of the INVITE, generated by the SUT. Figure 8.15 shows a well-formed INVITE request. A protocol analyzer, in this case Wireshark, allows checking that the INVITE message passes the ETSI TPs formulated according to the RFC 3261: - the INVITE includes at least to, from, CSeq, call-ID, max-forwards, contact and via headers; - the request-URI is set to the same URI value of the to header; the from header contains a TAG parameter; C 2009 by Taylor & Francis Group, LLC SIP Handbook: Services, Technologies, and Security 7t INVITE client transaction.pcap . Wireshark Bie Edit View Go Capture Analyze Statistics Help Filter: Expression Clear Apply Source Destination Protocol 14.696090 192.168.129.50 192.168.129.165 SIP/SOP Request: INVITE sip:1651120192.168.129.165, 15.106191 192.168.129.50 192.168.129.165 SIP/SDP Request: INVITE sip:1651120192.168.129.165, with 26.15.137459 192.168.129.165 192.168.129.50 Status: 100 Trying 29.15.811817 192.168.129.165 192.168.129.50 status: 180 Ringing 30 15.829482 192.168.129.165 192.168.129.50 Status: 180 Ringing 55 18 232344 192.168.129.165 192.168.129.50 SIP/SDP status: 200 OK with session description 62 18.303490 192.168.129.50 192.168.129.165 Request: ACK sip:1651120192.168.129.165 Frame 21 (596 bytes on wire, 596 bytes captured) Ethernet II, Src: Inte1_19:2f:66 (00:19:d1:19:2f:66), Dst: eltaNet_28:69:3f (00:30:ab:28:69:3f) Internet Protocol, Src: 192.168.129.50 (192.168.129.50), Dst: 192.168.129.165 (192.168.129.165) User Datagram Protocol, src Port: 5060 (5060), Dst Port: 5060 (5060) Session Initiation Protocol Request-Line: INVITE sip:1651120192.168.129.165 SIP/2.0 Message Header SIP/2.0/UDP 192.168.129.50:5060;branch=29hG4bK10000010 From: <sip:2351110192.168.129.165:5060>;tag=Stz0110000009 <sip:1651120192.168.129.165> Call-ID: 972238-100000080192.168.129.50 CSeq: 201 INVITE Max-Forwards 70 Contact: <sip:2351110192.168.129.50:5060> user-Agent: SPT simulator Content-Type: application/sdp Content-Length: 142 Message body 2