[Kamailio-Users] Relaying NOTIFY UDP messages over TCP

[Iñaki Baz Castillo]

2010/3/9 Pascal Maugeri <pascal.maugeri at gmail.com>:
> Hi
> We need to force some NOTIFY messages going through our kamailio instance
> over UDP to be sent over TCP.
> For that purpose we inserted the following relaying rule at the beginning of
> the routing script:
> route{
>
> if (!mf_process_maxfwd_header("10")) {
>   sl_send_reply("483","Too Many Hops");
>   exit;
> }
>
>   if(msg:len>1300 && is_method("NOTIFY") && proto==UDP)
>   {
>         $du = "sip:" + $(ruri{uri.host}) + ":" + $(ruri{uri.port}) +
> ";transport=tcp";
>         t_relay();
>         exit;
>   }
>
>
>
> [...]
>
> This works well if the destination of the NOTIFY message is not behind NAT.
> We're looking for a solution for the NAT case. We did some tests using
> lookup("location") before changing $du but we did not get any success.
> Do you have any idea on how to implement this relaying properly ?

Does such NOTIFY go to a TCP registered user? Of course if there is
not an existing TCP connection between Kamailio and the final natted
user then it's not possible to send such NOTIFY.



> Is it acceptable to change the $du and then execute the t_relay as we did ?

Yes.


-- 
Iñaki Baz Castillo
<ibc at aliax.net>