[OpenSIPS-Users] ACK looping behind NAT

[Bogdan-Andrei Iancu]

Hi,

Ideally you should provide a network capture (pcap) from the OpenSIPS 
server, covering both incoming and outgoing traffic - this is the only 
way to understand what is wrong with the call.

As attachments are limited to 40K here, consider using some pastebin or 
other file sharing service.

Regards,

Bogdan-Andrei Iancu

OpenSIPS Founder and Developer
   https://www.opensips-solutions.com
   https://www.siphub.com

On 11/13/23 1:26 PM, Sreeram Narayanan via Users wrote:
> Hello,
>
> I am trying to use OpenSIPs with the load_balancer module to balance 
> inbound calls between 2 Asterisk servers. The setup sits behind a NAT. 
> The OpenSIPs server has a public IP and a private IP. When an INVITE 
> arrives, it can forward it to one of the Asterisk servers and Asterisk 
> responds with a 200 OK. The problem starts when I receive the ACK 
> (from Twilio). The ACK starts bouncing between the public IP and 
> Private IP of the OpenSIPs server. It doesn't reach the 
> Asterisk server and eventually times out. I hope someone can help me 
> with this. Thanks in advance.
>
> Here is my configuration:
>
>     ####### Routing Logic ########
>     route {
>
>         if (is_method("INVITE")) {
>             rtpproxy_engage();
>         }
>
>         if ($rm=="INVITE") {
>
>             lb_start_or_next(1,"pstn");
>         }
>
>         t_check_trans();
>         record_route();
>
>         t_on_failure("GW_FAILOVER");
>
>         # route the request
>         if (!t_relay()) {
>             sl_reply_error();
>         }
>
>         exit;
>     }
>
>     route[RELAY] {
>         if (!t_relay()) {
>             sl_reply_error();
>         }
>         exit;
>     }
>
>     failure_route[GW_FAILOVER] {
>         if (t_was_cancelled()) {
>             exit;
>         }
>         # failure detection with redirect to next available trunk
>         if (t_check_status("(408)|([56][0-9][0-9])")) {
>             xlog("Failed trunk $rd/$du detected \n");
>         }
>     }
>
>
> -- 
> - Sreeram
>
> _______________________________________________
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> Users at lists.opensips.org
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