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</o:shapelayout></xml><![endif]--></head><body bgcolor=white lang=FR link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span lang=EN-GB style='color:#1F497D'>Hello Daniel,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB style='color:#1F497D'>Sorry, but I’m not sure to understand.<o:p></o:p></span></p><p class=MsoNormal><a name="_MailEndCompose"><span lang=EN-GB style='color:#1F497D'>Use the resolver included in Kamailio would be better in that case because the negative reply coming from outside resolver would be recorded for a timeperiod? In this timeperiod, no other DNS requests for the same type and the same host would be generated to the outside resolver? I’m right?<o:p></o:p></span></a></p><p class=MsoNormal><span lang=EN-GB style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB style='color:#1F497D'>In parallel, you can confirm that the SRV requests cannot be avoided?<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB style='color:#1F497D'>Regards,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB style='color:#1F497D'>Igor.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB style='color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-GB style='color:windowtext;mso-fareast-language:FR'>De :</span></b><span lang=EN-GB style='color:windowtext;mso-fareast-language:FR'> Daniel-Constantin Mierla [mailto:miconda@gmail.com] <br><b>Envoyé :</b> lundi 4 août 2014 16:18<br><b>À :</b> Igor Potjevlesch; 'Kamailio (SER) - Users Mailing List'<br><b>Objet :</b> Re: [SR-Users] Understanding DNS resolution done by Kamailio<o:p></o:p></span></p></div></div><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'>Hello,<br><br><span style='font-size:12.0pt;mso-fareast-language:FR'><o:p></o:p></span></p><div><p class=MsoNormal>On 04/08/14 14:20, Igor Potjevlesch wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal>Hello Daniel,<o:p></o:p></p><p class=MsoNormal> <o:p></o:p></p><p class=MsoNormal><span lang=EN-GB>Thank you. If I use the resolver included in Kamailio and if the response from the resolver is negative, is there a new DNS request sent for outgoing uri resolution?</span><o:p></o:p></p></blockquote><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif";mso-fareast-language:FR'><br>it should not be any other dns request -- it will fail sending.<br><br>Cheers,<br>Daniel<br><br><br><o:p></o:p></span></p><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal><span lang=EN-GB>If not, that would mitigate the volume of DNS requests sent.</span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB> </span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB>Regards,</span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB> </span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB>Igor.</span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB> </span><o:p></o:p></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b>De :</b> <a href="mailto:sr-users-bounces@lists.sip-router.org">sr-users-bounces@lists.sip-router.org</a> [<a href="mailto:sr-users-bounces@lists.sip-router.org">mailto:sr-users-bounces@lists.sip-router.org</a>] <b>De la part de</b> Daniel-Constantin Mierla<br><b>Envoyé :</b> vendredi 1 août 2014 08:46<br><b>À :</b> Kamailio (SER) - Users Mailing List<br><b>Objet :</b> Re: [SR-Users] Understanding DNS resolution done by Kamailio<o:p></o:p></p></div></div><p class=MsoNormal> <o:p></o:p></p><p class=MsoNormal style='margin-bottom:12.0pt'>Hello,<br><br>I don't think there is a way to disable dns for outgoing uri resolving, if you want disabling all dns.<br><br>The dns timeout is can be configured at the operating system level.<br><br>To avoid the sip worker blocking, you can try:<br><br>a) look at $nh(d) and if it is not an IP, then you can use async_route() (async_task_route() would be better, but now only in devel) or mqueue+rtimer to pass the relaying of the request to another worker process<br><br>b) and an intermediary proxy, so you send the requests with FQDN to it and it will return back to the proxy. You can send the dst-uri via some custom headers. This would be like:<br><br>[ua1] <===> [kamailio main] <===> [kamailio dns] <===> [kamailio main] <===> [ua2]<br><br>kamailio dns should not do record routing, because requests within dialog should have IP addresses.<br><br>Cheers,<br>Daniel<o:p></o:p></p><div><p class=MsoNormal>On 29/07/14 14:31, Igor Potjevlesch wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal><span lang=EN-GB>Hello,</span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB> </span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB>I’m using Kamailio 4.1 and I’m wondering how to avoid external DNS resolution.</span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB>I have the following config:</span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB>dns_cache_init=no</span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB>use_dns_cache=no</span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB>dns=no</span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB>rev_dns=no</span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB> </span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB>Even with this config, I have many and many DNS query on SRV _sip for the hostnames set in carrierroute module.</span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB>These requests are not useful because the A resolution is done by /etc/hosts.</span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB> </span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB>Major problem with this, is that when I have a DNS issue or IP transit issue, Kamailio waits for resolution timeout and becomes overloaded. As a consequence, Kamailio can’t treat others SIP requests like REGISTER because he stuck in DNS resolution.</span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB> </span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB>Regards,</span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB> </span><o:p></o:p></p><p class=MsoNormal><span lang=EN-GB>Igor.</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:12.0pt'><br><br><br></span><o:p></o:p></p><pre>_______________________________________________<o:p></o:p></pre><pre>SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list<o:p></o:p></pre><pre><a href="mailto:sr-users@lists.sip-router.org">sr-users@lists.sip-router.org</a><o:p></o:p></pre><pre><a href="http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users">http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users</a><o:p></o:p></pre></blockquote><p class=MsoNormal><span style='font-size:12.0pt'><br><br></span><o:p></o:p></p><pre>-- <o:p></o:p></pre><pre>Daniel-Constantin Mierla - <a href="http://www.asipto.com">http://www.asipto.com</a><o:p></o:p></pre><pre><a href="http://twitter.com/#%21/miconda">http://twitter.com/#!/miconda</a> - <a href="http://www.linkedin.com/in/miconda">http://www.linkedin.com/in/miconda</a><o:p></o:p></pre></blockquote><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif";mso-fareast-language:FR'><br><br><o:p></o:p></span></p><pre>-- <o:p></o:p></pre><pre>Daniel-Constantin Mierla - <a href="http://www.asipto.com">http://www.asipto.com</a><o:p></o:p></pre><pre><a href="http://twitter.com/#!/miconda">http://twitter.com/#!/miconda</a> - <a href="http://www.linkedin.com/in/miconda">http://www.linkedin.com/in/miconda</a><o:p></o:p></pre></div></body></html>