iax2 - unreachable issue

We have a number of FreePBX VMware ISO installations currently updated to where we are experiencing issues with inter-pbx IAX trunks. It works sometimes, sometimes it doesn’t and sometimes it connects in one-direction only.

Linked to the ASTERISK 18827 bug report below - reviewboard.asterisk.org/r/2427/


This describes the issues we are experiencing but wondered how this can be resolved on our current installations to avoid impacting on the usual module upgrade path we have used for keeping the system recent.

Perhaps there is something we need to do at command level??

We have older versions of FreePBX (1.4 and 1.6 Asterisk) where IAX works perfectly in the same VM environment, network segment etc.

Any help welcome before we end up reverting to SIP trunking!!