'[SR-Users] Understanding DNS resolution done by Kamailio'

[prev in list] [next in list] [prev in thread] [next in thread] 

List:       serusers
Subject:    [SR-Users] Understanding DNS resolution done by Kamailio
From:       "Igor Potjevlesch" <igor.potjevlesch () gmail ! com>
Date:       2014-07-29 12:31:28
Message-ID: 00c401cfab29$06584250$1308c6f0$ () gmail ! com
[Download RAW message or body]

This is a multipart message in MIME format.

[Attachment #2 (multipart/alternative)]
This is a multipart message in MIME format.

Hello,

I'm using Kamailio 4.1 and I'm wondering how to avoid external DNS
resolution.

I have the following config:

dns_cache_init=no

use_dns_cache=no

dns=no

rev_dns=no

Even with this config, I have many and many DNS query on SRV _sip for the
hostnames set in carrierroute module.

These requests are not useful because the A resolution is done by
/etc/hosts.

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.

Regards,

Igor.

[Attachment #5 (text/html)]

<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: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=us-ascii"><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;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
	{margin:0cm;
	margin-bottom:.0001pt;
	font-size:11.0pt;
	font-family:"Calibri","sans-serif";
	mso-fareast-language:EN-US;}
a:link, span.MsoHyperlink
	{mso-style-priority:99;
	color:#0563C1;
	text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
	{mso-style-priority:99;
	color:#954F72;
	text-decoration:underline;}
span.EmailStyle17
	{mso-style-type:personal-compose;
	font-family:"Calibri","sans-serif";
	color:windowtext;}
.MsoChpDefault
	{mso-style-type:export-only;
	font-family:"Calibri","sans-serif";
	mso-fareast-language:EN-US;}
@page WordSection1
	{size:612.0pt 792.0pt;
	margin:70.85pt 70.85pt 70.85pt 70.85pt;}
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=FR link="#0563C1" \
vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span \
lang=EN-GB>Hello,<o:p></o:p></span></p><p class=MsoNormal><span \
lang=EN-GB><o:p>&nbsp;</o:p></span></p><p class=MsoNormal><span lang=EN-GB>I&#8217;m \
using Kamailio 4.1 and I&#8217;m wondering how to avoid external DNS \
resolution.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB>I have the \
following config:<o:p></o:p></span></p><p class=MsoNormal><span \
lang=EN-GB>dns_cache_init=no<o:p></o:p></span></p><p class=MsoNormal><span \
lang=EN-GB>use_dns_cache=no<o:p></o:p></span></p><p class=MsoNormal><span \
lang=EN-GB>dns=no<o:p></o:p></span></p><p class=MsoNormal><span \
lang=EN-GB>rev_dns=no<o:p></o:p></span></p><p class=MsoNormal><span \
lang=EN-GB><o:p>&nbsp;</o:p></span></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.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB>These \
requests are not useful because the A resolution is done by \
/etc/hosts.<o:p></o:p></span></p><p class=MsoNormal><span \
lang=EN-GB><o:p>&nbsp;</o:p></span></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&#8217;t treat others SIP requests like REGISTER because he stuck in DNS \
resolution.<o:p></o:p></span></p><p class=MsoNormal><span \
lang=EN-GB><o:p>&nbsp;</o:p></span></p><p class=MsoNormal><span \
lang=EN-GB>Regards,<o:p></o:p></span></p><p class=MsoNormal><span \
lang=EN-GB><o:p>&nbsp;</o:p></span></p><p class=MsoNormal><span \
lang=EN-GB>Igor.<o:p></o:p></span></p></div></body></html>

_______________________________________________
SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
sr-users@lists.sip-router.org
http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users

[prev in list] [next in list] [prev in thread] [next in thread] 