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<p class="MsoNormal"><span style="mso-fareast-language:EN-US">Hello Antonis!<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="mso-fareast-language:EN-US">IMHO the carrier cannot expect Register and Invite going to the same destination if the SRV for _<i>the</i>_ service is load-balanced.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="mso-fareast-language:EN-US">We do offer such a service as carrier also but encountered the issue with LB on nearly every device, incl. phones. Since we also need the call to be established across the same service
endpoint selected in the Register process we set priorities on each SRV for each datacenter.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="mso-fareast-language:EN-US">For such cases we do additionally name two A records where the endpoint must register on both and then can do LB calls to each. Otherwise the carriers service must allow registers and
invites going different ways. It is **one** service based on the SRV entry!<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="mso-fareast-language:EN-US">Br<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="mso-fareast-language:EN-US">Walter<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="DE">Von:</span></b><span lang="DE"> Users <users-bounces@lists.opensips.org>
<b>Im Auftrag von </b>Antonios Psaras<br>
<b>Gesendet:</b> Freitag, 20. Juni 2025 11:24<br>
<b>An:</b> 'OpenSIPS users mailling list' <users@lists.opensips.org><br>
<b>Betreff:</b> [OpenSIPS-Users] Registrant & LB with SRV<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span lang="EN-US">Hello Team<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">I have the following situation.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">A telecom carrier requires SIP Registration prior to Dial out using SIP Domain and SRV Lookup.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">To achieve that I am using registrant module and load balancing module.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">The problem I have, is that in some cases registrant registers on different SBC of the Carrier than the one resolved by Load Balancer Module so my outbound calls are failing with 407.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">I have two thoughts but I do not know how to implement any of those.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<li class="MsoListParagraph" style="margin-left:0cm;mso-list:l0 level1 lfo3"><span lang="EN-US">Instead of using LB Modules, I will some how get the registrar IP from registrant module and statically route the calls through that. Is there a way to get that
information from registrant module?<o:p></o:p></span></li><li class="MsoListParagraph" style="margin-left:0cm;mso-list:l0 level1 lfo3"><span lang="EN-US">DNS lookup is done automatically only in case of 503 or timeout. Is there a way to force DNS lookup with in OpenSIP Script? If yes I can handle 407, force DNS Lookup,
create a new branch and re-send the call.<o:p></o:p></span></li></ol>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Any other thoughts are welcome<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Best regards<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Antonis Psaras<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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