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 $du to Contact's received parameter? 2015-01-19 22:02 GMT+04:00 Alex Balashov <abalas...@evaristesys.com>: > On 01/19/2015 12:56 PM, Dmitry Sytchev wrote: > > Is there a way to make save() use original request fields like >> T_req($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@lists.sip-router.org > http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users > -- Best regards, Dmitry Sytchev, IT Engineer
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