[OpenSIPS-Users] Is NAPTR query always necessary?

[Bogdan-Andrei Iancu]

Hi Eason,

according to RFC3263 ( SIP: Locating SIP Servers), if the explicit 
protocol and port is contain by the destination SIP URI, the proxy must 
try to do NAPTR and SRV lookups to discover what protocol and port to use...
If these records are missing, the default value ( UDP + 5060) are assumed.

these DNS lookups are done each time a requests is routed out (if not 
using IPs).

What happens in your case is a SIP looping on the proxy (sending the 
request to itself). You can check this with tcpdump/ngrep/wireshark , 
watching the traffic on LO interface.

Regards,
Bogdan


hsuan wrote:
> Hi all,
>
> I am newbie on opensips, I wonder if the NAPTR is necessary in some case? 
> When my sip domain is set to FQDN, the opensips server will send NAPTR query
> to DNS server. But there is no NAPTR supported DNS in my environment,
> although the opensips server will get the ip and port eventaully. 
> Why the opensips server will send NAPTR query again and again even though it
> already get the ip and port from DNS? When the opensips server get into the
> NAPTR loop, the user will get 483 too many hops finally and will not able to
> register to opensips server. Once if the sip domain is set to ip address,
> the user will register successfully. Is there any way to disable the NAPTR
> query in opensips server? Please advice.
>
> Best regards,
> Eason
>
>
>