Retransmitting #4 (no NAT) to IP LYNC SERVER:5068:
OPTIONS sip:IP LYNC SERVER SIP/2.0
Via: SIP/2.0/UDP IP ISSABEL:5060;branch=z9hG4bK336350d8
Max-Forwards: 70
From: "Unknown" <sip:Unknown@IP ISSABEL>;tag=as1f5f282c
To: <sip:IP LYNC SERVER>
Contact: <sip:Unknown@IP ISSABEL:5060>
Call-ID: 2d8d94186c16e0cd76dd9f56526f1a91@IP ISSABEL***:5060
CSeq: 102 OPTIONS
User-Agent: FPBX-2.11.0(11.25.3)
Date: Thu, 17 Oct 2019 14:03:22 GMT
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO, PUBLISH, MESSAGE
Supported: replaces, timer
Content-Length: 0