Frame 16 (793 bytes on wire, 793 bytes captured)
Ethernet II, Src: 00:60:49:80:19:72, Dst: 00:40:ca:64:4d:b6
Internet Protocol, Src Addr: XXX.XXX.XXX.XXX (XXX.XXX.XXX.XXX), Dst Addr: ZZZ.ZZZ.ZZZ.ZZZ (ZZZ.ZZZ.ZZZ.ZZZ)
User Datagram Protocol, Src Port: 5060 (5060), Dst Port: 5060 (5060)
Session Initiation Protocol
    Request-Line: INVITE sip:12345@ser-proxy.company.com SIP/2.0
        Method: INVITE
    Message Header
        Via: SIP/2.0/UDP XXX.XXX.XXX.XXX:0;branch=z9hG4bK49034757
        From: "5555551212" <sip:5555551212@XXX.XXX.XXX.XXX:0>;tag=as179a9554
            SIP from address: "5555551212" <sip:5555551212@XXX.XXX.XXX.XXX:0>
            SIP tag: as179a9554
        To: <sip:12345@ser-proxy.company.com>
        Contact: <sip:5555551212@XXX.XXX.XXX.XXX:0>
        Call-ID: 1a81835f546befdf79e855e33c6dc21b@XXX.XXX.XXX.XXX
        CSeq: 102 INVITE
        User-Agent: Asterisk PBX
        Date: Fri, 16 Jul 2004 01:00:21 GMT
        Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER
        Content-Type: application/sdp
        Content-Length: 265
    Message body
        Session Description Protocol
            Session Description Protocol Version (v): 0
            Owner/Creator, Session Id (o): root 14720 14720 IN IP4 XXX.XXX.XXX.XXX
            Session Name (s): session
            Connection Information (c): IN IP4 XXX.XXX.XXX.XXX
            Time Description, active time (t): 0 0
            Media Description, name and address (m): audio 13824 RTP/AVP 0 3 8 101
            Media Attribute (a): rtpmap:0 PCMU/8000
            Media Attribute (a): rtpmap:3 GSM/8000
            Media Attribute (a): rtpmap:8 PCMA/8000
            Media Attribute (a): rtpmap:101 telephone-event/8000
            Media Attribute (a): fmtp:101 0-16
            Media Attribute (a): silenceSupp:off - - - -

Frame 19 (474 bytes on wire, 474 bytes captured)
Ethernet II, Src: 00:03:e3:0c:cc:d3, Dst: 00:40:ca:64:4d:b6
Internet Protocol, Src Addr: YYY.YYY.YYY.YYY (YYY.YYY.YYY.YYY), Dst Addr: ZZZ.ZZZ.ZZZ.ZZZ (ZZZ.ZZZ.ZZZ.ZZZ)
User Datagram Protocol, Src Port: 5060 (5060), Dst Port: 5060 (5060)
Session Initiation Protocol
    Status-Line: SIP/2.0 400 Bad Request
        Status-Code: 400
    Message Header
        Via: SIP/2.0/UDP ZZZ.ZZZ.ZZZ.ZZZ;branch=z9hG4bK7dfd.2d50a291.0,SIP/2.0/UDP XXX.XXX.XXX.XXX:0;branch=z9hG4bK49034757
        From: "5555551212" <sip:5555551212@XXX.XXX.XXX.XXX:0>;tag=as179a9554
            SIP from address: "5555551212" <sip:5555551212@XXX.XXX.XXX.XXX:0>
            SIP tag: as179a9554
        To: <sip:12345@ser-proxy.company.com>
        Call-ID: 1a81835f546befdf79e855e33c6dc21b@XXX.XXX.XXX.XXX
        Date: Fri, 16 Jul 2004 01:00:21 GMT
        Warning: 399 Bad Request - 'Malformed/Missing FROM: field'
        CSeq: 102 INVITE
        Content-Length: 0