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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Hello Giovanni<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I totally agree with you. PRACK is an endpoint feature. But as you know, working with IMS, and having all kind or end point implementations of sip stack you need to do the dirty job in the middle for interoperability reasons. Commercial SBC have that feature called 100rel Interworking which can be enabled per Trunk. Hence, if a carrier requires 100rel/PRACK enforcement and the end point does not supporting it, the function is engaged and handles the PRACK locally.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I will check Bogdan suggestion but in the first read looks like a tmp work around which I am not sure if that can be scaled to few hundreds of CPS that we work with.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>As this is a feature that will be needed for VoLTE/5G/IMS networks my suggestion is to create a module for that.<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><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><b>From:</b> Giovanni Maruzzelli <gmaruzz@gmail.com> <br><b>Sent:</b> Πέμπτη, 13 Νοεμβρίου 2025 16:37<br><b>To:</b> apsaras@microbase.gr; OpenSIPS users mailling list <users@lists.opensips.org><br><b>Subject:</b> Re: [OpenSIPS-Users] 100rel / PRACK Interworking<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><div><pre><span style='color:black'><br><br><o:p></o:p></span></pre><pre><span style='color:black'><o:p> </o:p></span></pre><pre><span style='color:black'>El 26/02/2024 a las 7:43 a. m., Bogdan-Andrei Iancu escribió:<o:p></o:p></span></pre><pre><span style='color:black'>><i> yes, you can use the b2b_logic (together with b2b_entities) for that, <o:p></o:p></i></span></pre><pre><span style='color:black'>><i> but it may be a too heavy tool for the purpose. Maybe you can try to <o:p></o:p></i></span></pre><pre><span style='color:black'>><i> generate the PRACK from OpenSIPS level by using the t_uac_dlg MI <o:p></o:p></i></span></pre><pre><span style='color:black'>><i> function [1] via the mi_script module [2] - basically to trigger that <o:p></o:p></i></span></pre><pre><span style='color:black'>><i> MI cmd from the onreply_route, when receiving the 180 reply.<o:p></o:p></i></span></pre><pre><span style='color:black'>><i><o:p> </o:p></i></span></pre><pre><span style='color:black'>><i> [1] <a href="https://opensips.org/html/docs/modules/3.4.x/tm.html#mi_t_uac_dlg">https://opensips.org/html/docs/modules/3.4.x/tm.html#mi_t_uac_dlg</a><o:p></o:p></i></span></pre><pre><span style='color:black'>><i> [2] <a href="https://opensips.org/html/docs/modules/3.4.x/mi_script.html#afunc_mi">https://opensips.org/html/docs/modules/3.4.x/mi_script.html#afunc_mi</a> </i><o:p></o:p></span></pre><pre><span style='color:black'><o:p> </o:p></span></pre><pre><span style='color:black'><o:p> </o:p></span></pre></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Thu, Nov 13, 2025 at 3:34 PM Giovanni Maruzzelli <<a href="mailto:gmaruzz@gmail.com">gmaruzz@gmail.com</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><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><p class=MsoNormal>eg: <a href="https://lists.opensips.org/pipermail/users/2024-March/047880.html" target="_blank">https://lists.opensips.org/pipermail/users/2024-March/047880.html</a><o:p></o:p></p><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>On Thu, Nov 13, 2025 at 3:27 PM Giovanni Maruzzelli <<a href="mailto:gmaruzz@gmail.com" target="_blank">gmaruzz@gmail.com</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>Hello Antonio,<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>PRACK is actually an endpoint feature, at the proxy level you can only fake it...<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>On Thu, Nov 13, 2025 at 3:14 PM Antonios Psaras <<a href="mailto:apsaras@microbase.gr" target="_blank">apsaras@microbase.gr</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><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Dear Team<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>As many carriers requires 100rel for interoperability reason with IMS, the need for 100rel interworking is mandatory. Is there any solution available to implement that on OpenSIPs Proxy level?<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Regards<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Antonis Psaras<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p></div></div><p class=MsoNormal>_______________________________________________<br>Users mailing list<br><a href="mailto:Users@lists.opensips.org" target="_blank">Users@lists.opensips.org</a><br><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></p></div></blockquote></div><div><p class=MsoNormal><br clear=all><o:p></o:p></p></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></blockquote></div><div><p class=MsoNormal><br clear=all><o:p></o:p></p></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></blockquote></div><div><p class=MsoNormal><br clear=all><o:p></o:p></p></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></body></html>