recv 258 bytes from udp/[208.64.203.141]:5060 at 00:17:26.902356:
   ------------------------------------------------------------------------
   SIP/2.0 503 Service Unavailable
   Via: SIP/2.0/UDP 192.168.1.10:5060
   From: "mike" <sip:mike@192.168.1.10>;tag=m3tK37KUyQ8vg
   To: <sip:1234@conference.freeswitch.org>
   Call-ID: ae9d7586-efd6-122a-db90-0016e3aaf71c
   CSeq: 89782985 INVITE
   Content-Length: 0