Frame 20 (287 bytes on wire, 287 bytes captured)
Internet Protocol, Src Addr: 10.250.250.201 (10.250.250.201), Dst Addr: 10.250.250.101 (10.250.250.101)
User Datagram Protocol, Src Port: 5060 (5060), Dst Port: 5060 (5060)
Session Initiation Protocol
    Status line: SIP/2.0 401 Unauthorized
        Status-Code: 401
    Message Header
        Via: SIP/2.0/UDP 10.250.250.101:5060
        To: <sip:5550101@vocal2.engdomain.com>;tag=25836
        From: <sip:1017@vocal2.engdomain.com>;tag=2c18069
        Call-ID: call-1042670570-91@10.250.250.101
        CSeq: 1 ACK
        Content-Length: 0