Hi All! I'm having a serious issue with this client's box. They have FPBX 2.9 with Asterisk 1.6.2 and cannot upgrade these versions, it is not an option. After about 15 minutes, outbound calls drop. Below are my configurations and versions. I Googled and thought that is would be a session timers issue, but as you can see, I've added the session timers into the trunk details, as well as in sip_custom.conf (since we are using FPBX, cannot put it directly into sip.conf, but sip_custom.conf is referenced in that file).
Where else should I be looking to fix this issue? It can be replicated multiple times from different devices (phones, ATAs, softphone etc.) as well as from different networks. I also use Fail2Ban with IPTables. All help would be appreciated!
SIP Trunk Outbound Peer Details
Thank you once again!