[Kamailio-Users] DNS lookup for requests within dialog

[Daniel-Constantin Mierla]

Hello,

On 24.09.2009 12:10 Uhr, catalina oancea wrote:
> Hi,
>
> In my scenario kamailio is not a registrar, it's just a proxy
> forwarding requests from asterisk to the provider.
>   
I see.

As Juha said, REGISTER does not create a real dialog, since the contact 
in 200OK is the address of publisher not of destination. So a proxy does 
not have within-dialog like routing information.

So here is a hack you can try:
- add record route on your proxy
- the provider should add its own record route to REGISTER reply -- if 
it is kamailio, that is simple via append_to_reply() from textops, just 
before save() call.
- hope/pray that asterisk is using these dialog info for building 
re-registration messages
- on your kamailio route based on Route header


Cheers,
Daniel

>
> 2009/9/24 Daniel-Constantin Mierla <miconda at gmail.com>:
>   
>> Hello,
>>
>> On 24.09.2009 11:47 Uhr, catalina oancea wrote:
>>     
>>> Hi all,
>>>
>>>
>>> I tested the following scenario:
>>>
>>> astreisk                        kamailio                provider(hostname)
>>>        -------------------->    dns lookup     -------------------->
>>>          REGISTER 1                              REGISTER 1
>>>
>>>         <--------------------                      <--------------------
>>>          401                                          401
>>>
>>>          -------------------->   dns lookup     -------------------->
>>>          REGISTER 2                              REGISTER 2
>>>          (same dialog, increased cseq)
>>>
>>>
>>>
>>> It seems that kamailio does dns lookup again when receiving REGISTER
>>> 2, although both registers are part of the same dialog. Is this the
>>> expected behavior?
>>>
>>>
>>>       
>> IIRC now, there is no place in registrar related modules (registrar and
>> usrloc) where DNS query is done. You have some checks in your config that
>> caused that.
>>
>> There is also an option to fetch existing contacts from location and see if
>> it is an update (matching by call id and cseq) and do directly
>> save("location").
>>
>> Cheers,
>> Daniel
>>
>> --
>> Daniel-Constantin Mierla
>> * Kamailio SIP Masterclass, Nov 9-13, 2009, Berlin
>> * http://www.asipto.com/index.php/sip-router-masterclass/
>>
>>
>>     
>
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>   

-- 
Daniel-Constantin Mierla
* Kamailio SIP Masterclass, Nov 9-13, 2009, Berlin
* http://www.asipto.com/index.php/sip-router-masterclass/