[sr-dev] dns resolver issue (RFC3263)

[Klaus Darilion]

Indeed, this is not implemented correctly.

If you fix it, the question is: what should be used if there are SRV 
records for UDP and TCP?

AFAIK there is already a configuration option to choose the respective 
NAPTR records according to local priority. These config options could be 
reused.

See dns_udp_pref/dns_tcp_pref/... options in doc/dns.txt

regards
Klaus

On 29.10.2012 16:33, MÉSZÁROS Mihály wrote:
> Hi All,
>
> I am experiencing an issue when i try to contact xy at cisco.com.
> I found that kamailio/sip-router can't resolve by default resolving way
> a TCP + SRV records from domain cisco.com.
>
> e.g. cisco.com
>
>     misi at alma:~$ host -t NAPTR cisco.com
>     cisco.com has no NAPTR record
>     misi at alma:~$ host -t SRV _sip._udp.cisco.com
>     Host _sip._udp.cisco.com not found: 3(NXDOMAIN)
>     misi at alma:~$ host -t SRV _sip._tcp.cisco.com
>     _sip._tcp.cisco.com has SRV record 1 0 5060 vcsgw.cisco.com.
>     misi at alma:~$ host -t SRV _sips._tcp.cisco.com
>     _sips._tcp.cisco.com has SRV record 1 0 5061 vcsgw.cisco.com.
>
>
> I can't call xy at cisco.com because it does not exists an NAPTR record in
> domain cisco.com,
> and furthermore no SRV with udp.
>
> But it exists sip+tcp record
> and also exists an secure sip SRV, so sips+tcp record!
>
> I read rfc3263
> I find kamailio dns resolver is not working as it should according RFC3263.
>
> http://tools.ietf.org/html/rfc3263
>
>     _If no NAPTR records are found, the client constructs SRV queries
>     for those transport protocols it supports, and does a query for each._
>
>
> So kamailio should query all (udp, tcp, tls, sctp whatever) protocols.
>
> Can anyone help/guide me to create a fix to this issue?
> My plan is to create a patch to kamailio resolver, to correct and behave
> according RFC3263.
>
> Any help or guidance appreciated!
>
> Thanks,
> Misi
>
>
>
>
>
>
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