<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<font face="monospace">Thanks Antonios for sharing the links - give
me a bit of time to dig into and extract some info; to be honest I
find such docs quite useful as they provide real life examples -
the best you can get in order to understand how it should work.<br>
<br>
Regards,<br>
</font>
<pre class="moz-signature" cols="72">Bogdan-Andrei Iancu
OpenSIPS Founder and Developer
<a class="moz-txt-link-freetext" href="https://www.opensips-solutions.com">https://www.opensips-solutions.com</a>
<a class="moz-txt-link-freetext" href="https://www.siphub.com">https://www.siphub.com</a></pre>
<div class="moz-cite-prefix">On 25.11.2025 18:10, Antonios Psaras
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:1b7701dc5e26$10084d60$3018e820$@microbase.gr">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta name="Generator"
content="Microsoft Word 15 (filtered medium)">
<style>@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;}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;}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]-->
<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
style="font-family:Aptos" lang="EL"><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"
moz-do-not-send="true"><span lang="EN-US">PRACK
Interworking</span></a></span><span
style="font-family:Aptos"> and </span><span
style="font-family:Aptos" lang="EL"><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"
moz-do-not-send="true"><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
<a class="moz-txt-link-rfc2396E" href="mailto:users-bounces@lists.opensips.org"><users-bounces@lists.opensips.org></a> <b>On Behalf Of </b>Giovanni
Maruzzelli<br>
<b>Sent:</b> Τρίτη, 25 Νοεμβρίου 2025 13:14<br>
<b>To:</b> Bogdan-Andrei Iancu <a class="moz-txt-link-rfc2396E" href="mailto:bogdan@opensips.org"><bogdan@opensips.org></a><br>
<b>Cc:</b> Giovanni Maruzzelli <a class="moz-txt-link-rfc2396E" href="mailto:gmaruzz@opentelecom.it"><gmaruzz@opentelecom.it></a>;
OpenSIPS users mailling list <a class="moz-txt-link-rfc2396E" href="mailto:users@lists.opensips.org"><users@lists.opensips.org></a><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"
moz-do-not-send="true" class="moz-txt-link-freetext">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" moz-do-not-send="true"
class="moz-txt-link-freetext">https://www.opensips-solutions.com</a><o:p></o:p></pre>
<pre> <a href="https://www.siphub.com" target="_blank"
moz-do-not-send="true" class="moz-txt-link-freetext">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" moz-do-not-send="true"
class="moz-txt-link-freetext">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" moz-do-not-send="true"
class="moz-txt-link-freetext">Users@lists.opensips.org</a><o:p></o:p></pre>
<pre><a
href="http://lists.opensips.org/cgi-bin/mailman/listinfo/users"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">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>
</blockquote>
<br>
</body>
</html>