[2016-05-10 21:45:35] VERBOSE[2359] res_pjsip_logger.c: <--- Received SIP request (758 bytes) from UDP:10.8.0.3:5060 --->
REGISTER sip:10.8.0.1:5060 SIP/2.0^M
Via: SIP/2.0/UDP 10.8.0.3:5060;branch=z9hG4bK36399200^M
From: "2012" <sip:2012@10.8.0.1:5060>;tag=8c29f5359ea247b^M
To: "2012" <sip:2012@10.8.0.1:5060>^M
Call-ID: b0980da127386ff@10.8.0.3^M
CSeq: 262 REGISTER^M
Contact: <sip:2012@10.8.0.3:5060;transport=UDP>^M
Authorization: Digest username="2012", realm="asterisk", nonce="1462927534/be783b2629f98665a395e0a8bafa4ae1", uri="sip:10.8.0.1:5060", response="769740057936ca7d04062ff3a02efced", algorithm=MD5, cnonce="0a4f113b", opaque="1544a2fb0aff9103", qop=auth, nc=00000001^M
Max-Forwards: 70^M
Supported: path^M
User-Agent: Sangoma S300 V2.0.4.9^M
Expires: 900^M
Allow: INVITE, ACK, UPDATE, INFO, CANCEL, BYE, OPTIONS, REFER, SUBSCRIBE, NOTIFY, MESSAGE, PRACK^M
Content-Length: 0^M
^M

[2016-05-10 21:45:35] VERBOSE[30265] res_pjsip_logger.c: <--- Transmitting SIP response (412 bytes) to UDP:10.8.0.3:5060 --->
SIP/2.0 200 OK^M
Via: SIP/2.0/UDP 10.8.0.3:5060;rport=5060;received=10.8.0.3;branch=z9hG4bK36399200^M
Call-ID: b0980da127386ff@10.8.0.3^M
From: "2012" <sip:2012@10.8.0.1>;tag=8c29f5359ea247b^M
To: "2012" <sip:2012@10.8.0.1>;tag=z9hG4bK36399200^M
CSeq: 262 REGISTER^M
Date: Wed, 11 May 2016 00:45:35 GMT^M
Contact: <sip:2012@10.8.0.3:5060>;expires=899^M
Expires: 900^M
Server: FPBX-13.0.115(13.9.0)^M
Content-Length:  0^M
^M

.....

900 sec = 15 mins, so expiry should be at 22:00:35

However, it's expiring 32 seconds too early.


[2016-05-10 21:59:03] VERBOSE[8503] res_pjsip/pjsip_configuration.c: Contact 2012/ has been deleted
[2016-05-10 21:59:03] VERBOSE[8503] res_pjsip/pjsip_configuration.c: Endpoint 2012 is now Unreachable
[2016-05-10 22:00:03] VERBOSE[2359] res_pjsip_logger.c: <--- Received SIP request (494 bytes) from UDP:10.8.0.3:5060 --->
REGISTER sip:10.8.0.1:5060 SIP/2.0^M
Via: SIP/2.0/UDP 10.8.0.3:5060;branch=z9hG4bK3558fe2a^M
From: "2012" <sip:2012@10.8.0.1:5060>;tag=8c29f5359ea247b^M
To: "2012" <sip:2012@10.8.0.1:5060>^M
Call-ID: b0980da127386ff@10.8.0.3^M
CSeq: 263 REGISTER^M
Contact: <sip:2012@10.8.0.3:5060;transport=UDP>^M
Max-Forwards: 70^M
Supported: path^M
User-Agent: Sangoma S300 V2.0.4.9^M
Expires: 900^M
Allow: INVITE, ACK, UPDATE, INFO, CANCEL, BYE, OPTIONS, REFER, SUBSCRIBE, NOTIFY, MESSAGE, PRACK^M
Content-Length: 0^M
^M