<html>
  <head>
    <meta content="text/html; charset=utf-8" http-equiv="Content-Type">
  </head>
  <body bgcolor="#FFFFFF" text="#000000">
    <tt>Hi Rodrigo,<br>
      <br>
      That OPTIONS (even if it is really weird to have that OPTIONS
      inserted between 200OK and ACK) should not affect the cseq
      numbering in ACK as it is in opposite direction.<br>
      <br>
      If you manage to get rid of that OPTION, is the ACK cseq correct ?<br>
      <br>
      With this bogus scenario, can you run in log_level 4 (debug) and
      post the opensips logs (covering the whole call) for inspection ?
      <br>
      <br>
      Best regards,<br>
    </tt>
    <pre class="moz-signature" cols="72">Bogdan-Andrei Iancu
  OpenSIPS Founder and Developer
  <a class="moz-txt-link-freetext" href="http://www.opensips-solutions.com">http://www.opensips-solutions.com</a>

OpenSIPS Bootcamp 2017, Houston, US
  <a class="moz-txt-link-freetext" href="http://opensips.org/training/OpenSIPS_Bootcamp_2017.html">http://opensips.org/training/OpenSIPS_Bootcamp_2017.html</a>
</pre>
    <div class="moz-cite-prefix">On 06/26/2017 03:18 PM, Rodrigo Pimenta
      Carvalho wrote:<br>
    </div>
    <blockquote
cite="mid:DM5PR02MB321231D0EB1BC95154E26CC0B5DF0@DM5PR02MB3212.namprd02.prod.outlook.com"
      type="cite">
      <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
      <style type="text/css" style="display:none;"><!-- P {margin-top:0;margin-bottom:0;} --></style>
      <div id="divtagdefaultwrapper"
style="font-size:12pt;color:#000000;font-family:Calibri,Helvetica,sans-serif;"
        dir="ltr">
        <br>
        <div style="color: rgb(0, 0, 0);">
          <div>
            <div id="divtagdefaultwrapper" dir="ltr"
              style="font-size:12pt; color:#000000;
              font-family:Calibri,Arial,Helvetica,sans-serif">
              <div>Dear OpenSIPS users,<br>
                <br>
                I'm facing a problem related to CSeq numbers in SIP
                messages and maybe it is being caused by SIP OPTIONS
                messages.<br>
                When a caller sends a SIP ACK to the callee, the SIP ACK
                has CSeq = 2. However, after being relayed by OpenSIPS,
                the CSeq number become 3.<br>
                It seems that OpenSIPS decided to change such value on
                its own. But, maybe it was caused by the previous SIP
                OPTIONS message receive before.<br>
                The diagram bellow shows what is happening.<br>
                <br>
                Can the SIP OPTIONS message cause such issue? If yes,
                should I give up of using SIP OPTIONS? Can it be a bug
                in OpenSIPS?<br>
                If not, what is happening here??<br>
                If that CSeq remains like 3, the callee will simply
                discard the SIP ACK and send another SIP OK, will not
                discard?<br>
                <br>
                <br>
                <br>
                Caller                       
                OpenSIPs                          Callee<br>
                |                                         
                |                                        |<br>
                |                                         
                |                                        |<br>
                |       INVITE                     
                |                                        |<br>
                |       CSeq = 2                 
                |                                        |<br>
                |------------------------------->|       
                INVITE                    |<br>
                |                                         |        CSeq
                = 2                |<br>
                |                                        
                |------------------------------->|<br>
                <span>|                                        
                  |                                         |</span><br>
                |                                         |        
                TRYING                 |<br>
                |                                         |         CSeq
                = 2               |<br>
                |      TRYING                   
                |<-------------------------------|<br>
                |      CSeq = 2                  |                     
                                   |<br>
|<-------------------------------|                                   
                     |<br>
                <span>|                                         
                  |                                        |</span><br>
                |                                          |        
                RING                     |<br>
                |                                          |        
                CSeq = 2               |<br>
                |      RING                         
                |<-------------------------------|<br>
                |      CSeq = 2                 
                |                                          |<br>
|<-------------------------------|                                   
                      |<br>
                |                                         |         SIP
                OK                   |<br>
                |                                         |         CSeq
                = 2               |<br>
                |      SIP OK                     
                |<-------------------------------|<br>
                |      CSeq = 2                 
                |                                         |<br>
|<-------------------------------|                                  
                      |<br>
                |                                         |         SIP
                OK                   |<br>
                |                                         |         CSeq
                = 2               |<br>
                |      SIP OK                    
                |<-------------------------------|<br>
                |      CSeq = 2                 
                |                                         |<br>
|<-------------------------------|                                  
                      |<br>
                <span>|                                        
                  |                                        |</span><br>
                |                                         |        SIP
                OPTIONS       |<br>
                |                                         |        CSeq
                = 3                |        <<---- new CSeq<br>
                |                                        
                |<-------------------------------|<br>
                <span>|                                        
                  |                                         |</span><br>
                |                                         |         SIP
                500                  |<br>
                |                                         |         CSeq
                = 3               |<br>
                |                                        
                |------------------------------->|<br>
                |       ACK                         
                |                                        |<br>
                |       CSeq = 2                
                |                                         |<br>
                |------------------------------->|       
                ACK                        |<br>
                |                                         |        CSeq
                = 3                |      <<---- Cseq of ACK was
                changed by OpenSIPS.
                <br>
                |                                        
                |------------------------------->|<br>
                |       ACK                        
                |                                          |<br>
                |       CSeq = 2                
                |                                         |<br>
                |------------------------------->|       
                ACK                        |<br>
                |                                         |        CSeq
                = 3                |<br>
                |                                        
                |------------------------------->|<br>
                <span>|                                        
                  |                                         |</span><br>
                |                                         |         SIP
                OK                   |<br>
                |                                         |         CSeq
                = 2               |<br>
                |      SIP OK                     
                |<-------------------------------|<br>
                |      CSeq = 2                 
                |                                         |<br>
|<-------------------------------|                                  
                      |<br>
                |       ACK                        
                |                                         |<br>
                |       CSeq = 2                
                |                                         |<br>
                |------------------------------->|       
                ACK                        |<br>
                |                                         |        CSeq
                = 3                |<br>
                |                                        
                |------------------------------->|<br>
                <span>|                                        
                  |                                         |</span><br>
                |                                         |         SIP
                OK                   |<br>
                |                                         |         CSeq
                = 2               |<br>
                |                                        
                |<-------------------------------|    <<-------
                This SIP OK never receives a SIP ACK with CSeq = 2...and
                the problem continues.<br>
                <br>
                Any hint will be very helpful!!<br>
              </div>
              Best regards!<br>
              <p><br>
              </p>
              <div id="Signature">
                <div name="divtagdefaultwrapper"
                  style="font-family:Calibri,Arial,Helvetica,sans-serif;
                  font-size:; margin:0">
                  <div class="BodyFragment"><font size="2">
                      <div class="PlainText">RODRIGO PIMENTA CARVALHO<br>
                        Inatel Competence Center<br>
                        Software<br>
                        Ph: +55 35 3471 9200 RAMAL 979<br>
                      </div>
                    </font></div>
                </div>
              </div>
            </div>
          </div>
        </div>
      </div>
      <br>
      <fieldset class="mimeAttachmentHeader"></fieldset>
      <br>
      <pre wrap="">_______________________________________________
Users mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Users@lists.opensips.org">Users@lists.opensips.org</a>
<a class="moz-txt-link-freetext" href="http://lists.opensips.org/cgi-bin/mailman/listinfo/users">http://lists.opensips.org/cgi-bin/mailman/listinfo/users</a>
</pre>
    </blockquote>
    <br>
  </body>
</html>