Recently I have setup a FreePBX high availability with Vega 200 and faced issue for the call, after spending sometime found out where is the issue. In FreePBX HA setting we will have one IP assigned to each machine and we have one floating IP which will assigned to the active machine automatically, by right w\you will need to pint any endpoint and gateway to the floating IP so it will always route the request to the active server. For voice gateways this scenario working for the inbound call however your gateway will faced issue for the outbound call as the active server when sending any call to the gateway will send the real IP address of the server but we have setup the trunk based on the floating IP so gateway will consider the call request received from unauthorized IP and will reject the call.
Based on my experience on this setup you will need to allow call from all the 3 IP address use for HA setup in the gateway configuration to resolve this issue.
Here is the setting for Sangoma Vega gateway with FreePBX HA setup.
If you have done the first configuration through the Quick Config for the floating IP to point the gateway to your FreePBX then you will need go to Expert Config >> SIP and edite your SIP Profile to look like this:
For this you need to add more SIP Proxy for the additional IP address of the HA setup. Simply add the SIP Proxy by clicking at the Add button and key in your IP and the port number and then save it. You can add as many as FreePBX node you have in your HA to cover all your node connectivity with the Vega gateway.