<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=Windows-1252">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
pre
{mso-style-priority:99;
mso-style-link:"HTML Preformatted Char";
margin:0in;
margin-bottom:.0001pt;
font-size:10.0pt;
font-family:"Courier New";}
span.HTMLPreformattedChar
{mso-style-name:"HTML Preformatted Char";
mso-style-priority:99;
mso-style-link:"HTML Preformatted";
font-family:Consolas;}
span.EmailStyle21
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-US" link="blue" vlink="purple" style="word-wrap:break-word">
<div class="WordSection1">
<p class="MsoNormal">Bogdan,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Actually I was referring to these parts:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">If the initial offer is in an INVITE, the answer MUST be in a<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">reliable non-failure message from UAS back to UAC which is<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">correlated to that INVITE. For this specification, that is<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">only the final 2xx response to that INVITE. That same exact<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">answer MAY also be placed in any provisional responses sent<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">prior to the answer. The UAC MUST treat the first session<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">description it receives as the answer, and MUST ignore any<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">session descriptions in subsequent responses to the initial<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">INVITE.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">…<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">Concretely, the above rules specify two exchanges for UAs compliant<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">to this specification alone - the offer is in the INVITE, and the<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">answer in the 2xx (and possibly in a 1xx as well, with the same<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">value), or the offer is in the 2xx, and the answer is in the ACK.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">All user agents that support INVITE MUST support these two exchanges.<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<p class="MsoNormal"><span style="color:black">Ben Newlin </span><o:p></o:p></p>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal" style="margin-bottom:12.0pt"><b><span style="font-size:12.0pt;color:black">From:
</span></b><span style="font-size:12.0pt;color:black">Bogdan-Andrei Iancu <bogdan@opensips.org><br>
<b>Date: </b>Wednesday, October 6, 2021 at 2:37 AM<br>
<b>To: </b>OpenSIPS users mailling list <users@lists.opensips.org>, Ben Newlin <Ben.Newlin@genesys.com><br>
<b>Subject: </b>Re: [OpenSIPS-Users] question on call handling.<o:p></o:p></span></p>
</div>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-family:"Courier New"">Hi Ben,<br>
<br>
The paragraph you refer to is this one :</span><o:p></o:p></p>
<pre> o After having sent or received an answer to the first offer, the<o:p></o:p></pre>
<pre> UAC MAY generate subsequent offers in requests based on rules<o:p></o:p></pre>
<pre> specified for that method, but only if it has received answers<o:p></o:p></pre>
<pre> to any previous offers, and has not sent any offers to which it<o:p></o:p></pre>
<pre> hasn't gotten an answer.<o:p></o:p></pre>
<p class="MsoNormal"><span style="font-family:"Courier New""><br>
So the 200 must contain the same SDP as the 180 because there is no SDP replied back between the 180 and 200 ?<br>
<br>
Regards,<br>
<br>
</span><o:p></o:p></p>
<pre>Bogdan-Andrei Iancu<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>OpenSIPS Founder and Developer<o:p></o:p></pre>
<pre> <a href="https://www.opensips-solutions.com">https://www.opensips-solutions.com</a><o:p></o:p></pre>
<pre>OpenSIPS eBootcamp 2021 <o:p></o:p></pre>
<pre> <a href="https://opensips.org/training/OpenSIPS_eBootcamp_2021">https://opensips.org/training/OpenSIPS_eBootcamp_2021/</a><o:p></o:p></pre>
<div>
<p class="MsoNormal">On 10/1/21 5:41 PM, Ben Newlin wrote:<o:p></o:p></p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal">No, this is not allowed by the specification, though some devices do handle it.<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal"><a href="https://datatracker.ietf.org/doc/html/rfc3261#section-13.2.1">https://datatracker.ietf.org/doc/html/rfc3261#section-13.2.1</a><o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<div>
<p class="MsoNormal"><span style="color:black">Ben Newlin </span><o:p></o:p></p>
</div>
<p class="MsoNormal"> <o:p></o:p></p>
<div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal" style="margin-bottom:12.0pt"><b><span style="font-size:12.0pt;color:black">From:
</span></b><span style="font-size:12.0pt;color:black">Users <a href="mailto:users-bounces@lists.opensips.org">
<users-bounces@lists.opensips.org></a> on behalf of johan <a href="mailto:johan@democon.be">
<johan@democon.be></a><br>
<b>Date: </b>Friday, October 1, 2021 at 10:35 AM<br>
<b>To: </b>OpenSIPS users mailling list <a href="mailto:users@lists.opensips.org">
<users@lists.opensips.org></a><br>
<b>Subject: </b>[OpenSIPS-Users] question on call handling.</span><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="margin-bottom:12.0pt">Dears,<br>
<br>
<br>
this is more a general sip question. when establishing a dialog is it<br>
then allowed to change the sdp that you have sent in 183 to somehting<br>
else in 200 Ok ?<br>
<br>
<br>
wkr,<br>
<br>
<br>
_______________________________________________<br>
Users mailing list<br>
<a href="mailto:Users@lists.opensips.org">Users@lists.opensips.org</a><br>
<a href="http://lists.opensips.org/cgi-bin/mailman/listinfo/users">http://lists.opensips.org/cgi-bin/mailman/listinfo/users</a><o:p></o:p></p>
</div>
<p class="MsoNormal"><br>
<br>
<o:p></o:p></p>
<pre>_______________________________________________<o:p></o:p></pre>
<pre>Users mailing list<o:p></o:p></pre>
<pre><a href="mailto:Users@lists.opensips.org">Users@lists.opensips.org</a><o:p></o:p></pre>
<pre><a href="http://lists.opensips.org/cgi-bin/mailman/listinfo/users">http://lists.opensips.org/cgi-bin/mailman/listinfo/users</a><o:p></o:p></pre>
</blockquote>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
</body>
</html>