SIP/2.0 478 Unresolvable destination (478/SL)
Via: SIP/2.0/UDP asterisk_ip:asterisk_port;branch=z9hG4bK18626d14;rport=50600;received=10.4.1.14
From: "Admin Admin" <sip:some_user@asterisk_ip:asterisk_port>;tag=as09b1f1f3
To: <sip:some_user@kamailio_ip:kamailio_port>;tag=a1384aaeda4d71b5edb13882669b943e.8468
Call-ID: 20e023254f1b3c942a61e47d63badfd6@10.4.1.14:50600
CSeq: 102 INVITE
Server: MS Lync
Content-Length: 0