<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:x="urn:schemas-microsoft-com:office:excel" 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=utf-8"><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:Aptos;}
@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:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
pre
{mso-style-priority:99;
mso-style-link:"HTML Preformatted Char";
margin:0cm;
margin-bottom:.0001pt;
font-size:10.0pt;
font-family:"Courier New";}
p.msonormal0, li.msonormal0, div.msonormal0
{mso-style-name:msonormal;
mso-margin-top-alt:auto;
margin-right:0cm;
mso-margin-bottom-alt:auto;
margin-left:0cm;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
span.HTMLPreformattedChar
{mso-style-name:"HTML Preformatted Char";
mso-style-priority:99;
mso-style-link:"HTML Preformatted";
font-family:Consolas;}
span.gmailsignatureprefix
{mso-style-name:gmail_signature_prefix;}
span.EmailStyle21
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle22
{mso-style-type:personal-compose;
font-family:"Calibri",sans-serif;
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri",sans-serif;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
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><div class=WordSection1><p class=MsoNormal>Hello Team<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>In most cases PRACK is needed for early audio services like <span style='font-family:Aptos'>Malicious Call Announcement. In those case the presence of 100rel and UPDATE is required. As this is a very well known issue and has already been implemented to few SBC Vendors, I suggest to check the documentation of such feature and implement something similar.<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Here are two links for <span lang=EL style='font-family:Aptos'><a href="https://docs.oracle.com/en/industries/communications/session-border-controller/9.1.0/configuration/sip-prack-interworking.html#GUID-DF953FC6-35D0-4C8B-8812-3D7E72F7795E"><span lang=EN-US>PRACK Interworking</span></a></span><span style='font-family:Aptos'> and </span><span lang=EL style='font-family:Aptos'><a href="https://docs.oracle.com/en/industries/communications/session-border-controller/9.1.0/configuration/update-interworking.html#GUID-17824ABA-36FE-4E50-A6EB-F3BADEA9767E"><span lang=EN-US>UPDATE Interworking</span></a></span><span style='font-family:Aptos'><o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>As these features are prerequisite for a project we are involved, we are willing to contribute in any way to speed up the process.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Regards<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:0cm;margin-right:0cm;margin-bottom:9.0pt;margin-left:1.0pt;line-height:16.5pt'><b><span style='color:#5F5F5F'><o:p> </o:p></span></b></p><p class=MsoNormal style='mso-margin-top-alt:0cm;margin-right:1.0pt;margin-bottom:5.0pt;margin-left:1.0pt'><b><span style='color:#5F5F5F'>Antonis Psaras</span></b><span style='color:#595959'><o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><b>From:</b> Users <users-bounces@lists.opensips.org> <b>On Behalf Of </b>Giovanni Maruzzelli<br><b>Sent:</b> Τρίτη, 25 Νοεμβρίου 2025 13:14<br><b>To:</b> Bogdan-Andrei Iancu <bogdan@opensips.org><br><b>Cc:</b> Giovanni Maruzzelli <gmaruzz@opentelecom.it>; OpenSIPS users mailling list <users@lists.opensips.org><br><b>Subject:</b> Re: [OpenSIPS-Users] PRACK interworking requirements<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal><o:p> </o:p></p></div><div><div><p class=MsoNormal>On Tue, Nov 25, 2025, 11:57 Bogdan-Andrei Iancu <<a href="mailto:bogdan@opensips.org">bogdan@opensips.org</a>> wrote:<o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm'><div><p class=MsoNormal><span style='font-family:"Courier New"'><br>The result here should be a dlg dedicated function to generate a PRACK from the onreply_route, like "dlg_answer_with_prack()" kind of function? or should we look into a more automatic approach, like flagging the dialog at creation to automatically generate the PRACK upon replies flagged with so?</span><o:p></o:p></p></div></blockquote></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>personally I'm a control freak and would like better an explicit function, maybe even with parameters to modify things if needed :))<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>-giovanni<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm'><div><p class=MsoNormal><span style='font-family:"Courier New"'><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" target="_blank">https://www.opensips-solutions.com</a><o:p></o:p></pre><pre> <a href="https://www.siphub.com" target="_blank">https://www.siphub.com</a><o:p></o:p></pre><div><p class=MsoNormal>On 25.11.2025 11:46, Giovanni Maruzzelli wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><div><div><p class=MsoNormal>hello OpenSIPSers,<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>in previous mails has been noticed that various ITSPs are starting to require PRACK support.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>We know that PRACK belongs to endpoints, specifically phones and B2BUAs.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>But...<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>There can be a use case where OpenSIPS will work as SBC (not necessarily using the b2b module)<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>So, we can have a case where we would like to support that the dialogue module insert the 100rel in the Supported: INVITE's header, and manage to send a PRACK method to acknowledge provisional responses<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>If and when 100rel/PRACK are "generated" by OpenSIPS, they will be filtered out (not propagated) to/from the endpoints, even if the endpoint would like to support it<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Reference RFC: <a href="https://www.ietf.org/rfc/rfc3262.txt" target="_blank">https://www.ietf.org/rfc/rfc3262.txt</a><o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I believe this will be enough to make ITSPs happy.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Further developments can be moved to future.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Would be very very nice to have this feature backported to OpenSIPS 3.6, being it the last of the 3.X series, and an LTS<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Please let's gather here your thoughts , requests, corrections and observations on this issue.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Have a nice Monday you all!<o:p></o:p></p></div><div><p class=MsoNormal><span style='color:#888888'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='color:#888888'>-giovanni<o:p></o:p></span></p></div></div><div><p class=MsoNormal><o:p> </o:p></p></div><p class=MsoNormal><span class=gmailsignatureprefix>-- </span><o:p></o:p></p><div><p class=MsoNormal style='margin-bottom:12.0pt'>Sincerely,<br><br>Giovanni Maruzzelli<br>OpenTelecom.IT<br>cell: +39 347 266 56 18<o:p></o:p></p></div></div><p class=MsoNormal><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" target="_blank">Users@lists.opensips.org</a><o:p></o:p></pre><pre><a href="http://lists.opensips.org/cgi-bin/mailman/listinfo/users" target="_blank">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></blockquote></div></div></div></body></html>