[Serusers] NAT Traversal using nathelper module

[Kostas Marneris]

thanks a lot.

I use the following and everything seems Ok ...


onreply_route[1] {
        if (status=~"(180)|(183)|2[0-9][0-9]") {
                if (!search("^Content-Length:[ ]*0")) {
                        if (nat_uac_test("13")) {
                                log(1, " - Reply behind NAT...");
                                setflag(7);
                                force_rport();
                                fix_nated_contact();
                                fix_nated_sdp("3");
                        };
                };
        };

}


Kostas

samuel wrote:
> I would add a condition like
> 
>  if (!search("^Content-Length:[ ]*0")) {
>        fix_mated_sdp()
>  }
> 
> So replies without body (180,100,101,...) will not raise the ERROR you
> have in the logs.
> 
> It would be also nice to check wether the reply is not an error (>299)
> so you do not need to use NAT transversal for error replies.
> if (status=~"(180)|(183)|2[0-9][0-9]") {
> 
> }
> I recommend you to check www.onsip.org and the discussion about the
> on_reply route in the getting started and the config files.
> 
> Hope it helps,
> 
> Samuel.
> 
> 
> 2006/5/3, Kostas Marneris <K.Marneris at otenet.gr>:
> 
>>Hello all,
>>
>>I'm trying to find a solution to overcome the NAT issue using only the nathelper module.
>>(I've already successfully worked with 'STUN' & 'MediaProxy'
>>solutions but I'm trying also this).
>>
>>
>>1. OUTBOUND direction:
>>--- INVITE handler ---
>>        ...
>>        # NAT Traversal mechanism for INVITEs
>>        if (nat_uac_test("19")) {
>>                setflag(7);
>>                force_rport();
>>                fix_nated_contact();
>>                fix_nated_sdp("3");
>>        };
>>        #
>>        ...
>>
>>The solution above works fine for OUTBOUND calls,
>>either on-net (a) or off-net (b). (For off-net calls I use a Cisco GW).
>>
>>a/ SIP_UA_behind_NAT -------- SER ------- SIP_UA_on_public_IP
>>b/ SIP_UA_behind_NAT -------- SER ------- Cisco_PSTN_GW ------- PSTN
>>
>>
>>
>>
>>2. INBOUND direction:
>>route[1] {
>>        # Default Message Handler
>>        t_on_reply("1");
>>        if (!t_relay()) {
>>                log(1, "  - Cannot RELAY !!!");
>>                sl_reply_error();
>>        };
>>}
>>
>>onreply_route[1] {
>>        if (nat_uac_test("19")) {
>>                log(1, " - Response behind NAT...");
>>                setflag(7);
>>                force_rport();
>>                fix_nated_contact();
>>                fix_nated_sdp("3");
>>        };
>>
>>}
>>
>>
>>Although I have two-way audio between calling and called parties,
>>I get the following logging mesgs :
>>
>>May  3 17:22:26 server ./ser[13705]: ERROR: extract_body: message body has length zero
>>May  3 17:22:26 server ./ser[13705]: ERROR: fix_nated_sdp: cannot extract body from msg!
>>May  3 17:22:26 server ./ser[13705]: ERROR: on_reply processing failed
>>
>>
>>
>>My question is :
>>Is the above the correct way for NAT traversal of SIP Responses (200 OK) ?
>>Do I have to add something else somewhere in ser.cfg ?
>>Any idea on the log mesgs above ?
>>
>>
>>thanks in advance for any help,
>>Kostas
>>
>>_______________________________________________
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>>serusers at lists.iptel.org
>>http://lists.iptel.org/mailman/listinfo/serusers
>>
> 
> 
> 
>