On 9/12/07, Halomoan Chow < halomoan@gmail.com> wrote:

I copy and paste the logic example generated from sipwise below.
I can see for first request, it marked the sender is behind nat with record_route(";nat=yes")

In the loose route block, it tries to identify sender if they are behind nat with search("^Route:.*;nat=yes").

In one sip proxy architecture, after you enter loose_route() function, the Via with ;nat has gone, right? and the search("^Route:.*;nat=yes") test would always return false.
Please correct me if i'm wrong. Thank you.

        if(!is_method("REGISTER"))
        {
                if(nat_uac_test("19"))
                {
                        record_route(";nat=yes");
                }
                else
                {
                        record_route();
                }
        }
        if(is_method("CANCEL") || is_method("BYE"))
        {
                end_media_session();
        }

        if(loose_route())
        {
                if(!has_totag())
                {

                        xlog("L_INFO", "Initial loose-routing rejected - M=$rm RURI=$ru F=$fu T=$tu IP=$si ID=$ci\n");
                        sl_send_reply("403", "Initial Loose-Routing Rejected");
                        exit;
                }
                if(nat_uac_test("19") || search("^Route:.*;nat=yes"))
                {
                        fix_nated_contact();
                        setbflag(6);
                }

                route(3);

        }

On 9/12/07, Bogdan-Andrei Iancu <bogdan@voice-system.ro> wrote:
Hi Halomoan,

Mainly because the NAT detection on SIP replied is very poor - you can
check only if the contact address is a private one or not. The other nat
test are not applicable for replies (but only for requests).

Anthow, when you process the request, you learn that the calee is behind
NAT, so you can simple remember this (in RR) than detecting it each time
when receiving a reply.

regards,
bogdan

Halomoan Chow wrote:
> Dear All
>
> I don't understand why in the Openser+MediaProxy i need
> record_route_preset("x.x.x.x:5060;nat=yes"); and
> search("^Route:.*;nat=yes")
> What is the purpose while I can do client_nat_test to see if the
> request is come from a nat-ed client.
>
> If I remove search("^Route:.*;nat=yes") from below statement, I can do
> re-INVITE without any problem because it still have client_nat_test to
> find out the nat in between.
>
> if (client_nat_test("3") || search("^Route:.*;nat=yes")) {
>    setbflag(6);
>    use_media_proxy();
> };
>
>
> Hope someone can give me a clue.
>
> Thank you.
>
> Regards,
>
> Halomoan
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