<div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">Hi,</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">What is the reason that the OPTION requests that are sent as an endpoint  "qualify" messages contain the endpoint IP in the "From" header field even when the endpoint was registered with domain name?</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">In the example below you can see a REGISTER request with "<a href="http://guest130.in.example.com">guest130.in.example.com</a>". But the OPTION request contains the endpoint IP address: 192.168.6.130. </div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default"><div class="gmail_default"><font face="arial, helvetica, sans-serif"><--- Received SIP request (742 bytes) from UDP:<a href="http://192.168.0.178:5060">192.168.0.178:5060</a> ---></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">REGISTER sip:<a href="http://guest130.in.example.com">guest130.in.example.com</a> SIP/2.0</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Via: SIP/2.0/UDP 192.168.0.178;rport;branch=z9hG4bKgtecduov</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Max-Forwards: 70</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">To: "2000" <<a href="mailto:sip%3A2000@guest130.in.example.com">sip:2000@guest130.in.example.com</a>></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">From: "2000" <<a href="mailto:sip%3A2000@guest130.in.example.com">sip:2000@guest130.in.example.com</a>>;tag=bfxca</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Call-ID: <a href="mailto:gnvsodaufttiokp@e540.in.example.com">gnvsodaufttiokp@e540.in.example.com</a></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">CSeq: 106 REGISTER</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Contact: <<a href="mailto:sip%3A2000@192.168.0.178">sip:2000@192.168.0.178</a>>;expires=3600</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Authorization: Digest username="2000",realm="asterisk",nonce="1540725445/cec702219f22cf0348eba188cc630606",uri="sip:<a href="http://guest130.in.example.com">guest130.in.example.com</a>",response="d4d0b238240a3c7c219e5c5b2f3d04d4",algorithm=md5,cnonce="e9c020189d",opaque="1051c93944cc4ec4",qop=auth,nc=00000001</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Allow: INVITE,ACK,BYE,CANCEL,OPTIONS,PRACK,REFER,NOTIFY,SUBSCRIBE,INFO,MESSAGE</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">User-Agent: Twinkle/1.10.1</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Content-Length: 0</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif"><br></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif"><br></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">    -- Added contact '<a href="http://sip:2000@192.168.0.178:5060">sip:2000@192.168.0.178:5060</a>' to AOR '2000' with expiration of 3600 seconds</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif"><--- Transmitting SIP response (445 bytes) to UDP:<a href="http://192.168.0.178:5060">192.168.0.178:5060</a> ---></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">SIP/2.0 200 OK</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Via: SIP/2.0/UDP 192.168.0.178;rport=5060;received=192.168.0.178;branch=z9hG4bKgtecduov</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Call-ID: <a href="mailto:gnvsodaufttiokp@e540.in.example.com">gnvsodaufttiokp@e540.in.example.com</a></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">From: "2000" <<a href="mailto:sip%3A2000@guest130.in.example.com">sip:2000@guest130.in.example.com</a>>;tag=bfxca</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">To: "2000" <<a href="mailto:sip%3A2000@guest130.in.example.com">sip:2000@guest130.in.example.com</a>>;tag=z9hG4bKgtecduov</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">CSeq: 106 REGISTER</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Date: Sun, 28 Oct 2018 11:17:25 GMT</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Contact: <<a href="http://sip:2000@192.168.0.178:5060">sip:2000@192.168.0.178:5060</a>>;expires=3599</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Server: FPBX-14.0.1.24(13.18.4)</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Content-Length:  0</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif"><br></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif"><br></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif"><--- Transmitting SIP request (429 bytes) to UDP:<a href="http://192.168.0.178:5060">192.168.0.178:5060</a> ---></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">OPTIONS <a href="http://sip:2000@192.168.0.178:5060">sip:2000@192.168.0.178:5060</a> SIP/2.0</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Via: SIP/2.0/UDP 192.168.6.130:5060;rport;branch=z9hG4bKPjc71c80bc-ca08-4cf6-8217-acd4efd2a315</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">From: <<a href="mailto:sip%3A2000@192.168.6.130">sip:2000@192.168.6.130</a>>;tag=900097b8-a32d-448e-941f-47d3294d757e</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">To: <<a href="mailto:sip%3A2000@192.168.0.178">sip:2000@192.168.0.178</a>></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Contact: <<a href="http://sip:2000@192.168.6.130:5060">sip:2000@192.168.6.130:5060</a>></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Call-ID: e68ce015-59f1-4608-aab1-d7faa2356752</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">CSeq: 61277 OPTIONS</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Max-Forwards: 70</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">User-Agent: FPBX-14.0.1.24(13.18.4)</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Content-Length:  0</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif"><br></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif"><br></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif"><--- Received SIP response (558 bytes) from UDP:<a href="http://192.168.0.178:5060">192.168.0.178:5060</a> ---></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">SIP/2.0 200 OK</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Via: SIP/2.0/UDP 192.168.6.130:5060;received=192.168.6.130;rport=5060;branch=z9hG4bKPjc71c80bc-ca08-4cf6-8217-acd4efd2a315</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">To: <<a href="mailto:sip%3A2000@192.168.0.178">sip:2000@192.168.0.178</a>>;tag=wjyqq</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">From: <<a href="mailto:sip%3A2000@192.168.6.130">sip:2000@192.168.6.130</a>>;tag=900097b8-a32d-448e-941f-47d3294d757e</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Call-ID: e68ce015-59f1-4608-aab1-d7faa2356752</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">CSeq: 61277 OPTIONS</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Accept: application/sdp</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Accept-Encoding: identity</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Accept-Language: en</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Allow: INVITE,ACK,BYE,CANCEL,OPTIONS,PRACK,REFER,NOTIFY,SUBSCRIBE,INFO,MESSAGE</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Server: Twinkle/1.10.1</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Supported: replaces,norefersub,100rel</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Content-Length: 0</font></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">The interesting points are:</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">*  INVITE and NOTIFY requests are sent with domain name and the IP is used in the OPTIONS requests only<br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">* the same behavior I see in case of chan_sip and pjsip.</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"> Thank you,</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">Leonid</div></div></div></div></div>