[SR-Users] REGISTER request and save() from onreply_route

[Dmitry Sytchev]

BTW, is there any way to alias contacts on Kamailio side and then on INVITE
use rewritten contact as base for real (original untouched) contact lookup,
like using 'received' field as lookup source?

And thanks for your detailed reply, I'll dig into the docs about 'received'
handling.

2015-01-19 22:23 GMT+04:00 Dmitry Sytchev <kbdfck at gmail.com>:

> Yes, you're right about contact matching and ATAs, this is a part of our
> case too.
> I actually use Path module to forward REGISTERs to backend servers. But
> there is a problem that not all backends support Path, like Asterisk 11.
>
> If I get the point right, I should forward them as is and when I receive
> request from backend set $ru to contact and $du to Contact's received
> parameter?
>
>
>
> 2015-01-19 22:02 GMT+04:00 Alex Balashov <abalashov at evaristesys.com>:
>
>> On 01/19/2015 12:56 PM, Dmitry Sytchev wrote:
>>
>>  Is there a way to make save() use original request fields like
>>> T_req($ct), or some way to call save() with full set of custom params?
>>>
>>
>> Yes; in fact, there are many standards-based reasons why it's desirable
>> to store the original Contact binding provided by the registrant. Many
>> devices (e.g. ATAs, various gateways, for instance) will not accept an
>> INVITE with an incoming Request URI that does not correspond to the exact
>> Contact URI that it sent in the REGISTER request.
>>
>> This is why Kamailio's usrloc record provides a 'received' field in
>> addition to a 'contact' field. Take a look at this:
>>
>> http://kamailio.org/docs/modules/4.2.x/modules/
>> registrar.html#registrar.p.received_param
>>
>> In essence, what you want is for the external IP:port to be stored in the
>> 'received' value while the original Contact is stored in the 'contact'
>> value. The 'received' value will be used as the destination set ($du) for
>> inbound routing, while the Request URI will remain consistent with the
>> Contact URI.
>>
>> The issue of having two proxies is a separate and more complex one.
>> Ultimately, to make it work, you're going to need to use Path, which is
>> like Record-Route, but for REGISTERs:
>>
>> http://kamailio.org/docs/modules/4.2.x/modules/
>> registrar.html#registrar.p.path_mode
>>
>> But, the first step to solving your problem is to realise that you should
>> not actually be rewriting the Contact header as your NAT traversal
>> strategy. You should add the received IP:port as parameters in one way or
>> another to be passed onto the receiving registrar, as for example using
>> Contact URI header parameters per the received_param doc I linked to above.
>>
>> -- Alex
>>
>> --
>> Alex Balashov - Principal
>> Evariste Systems LLC
>> 235 E Ponce de Leon Ave
>> Suite 106
>> Decatur, GA 30030
>> United States
>>
>> Tel: +1-678-954-0670
>> Web: http://www.evaristesys.com/, http://www.alexbalashov.com/
>>
>> _______________________________________________
>> SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
>> sr-users at lists.sip-router.org
>> http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
>>
>
>
>
> --
> Best regards,
>
> Dmitry Sytchev,
> IT Engineer
>



-- 
Best regards,

Dmitry Sytchev,
IT Engineer
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.sip-router.org/pipermail/sr-users/attachments/20150119/88fa7e9f/attachment.html>