Add support for outbound OPTIONS ping from carrier trunk

[davehorton]

We should have an option for outbound gateways to send OPTIONS pings to the remote gateway. This of course is only valid for sip gateways that are outbound. There should be a checkbox for each outbound gateway in the webapp labeled "send OPTIONS ping". If checked, the system (sbc-sip-sidecar) should send an OPTIONS ping every 60 seconds (this should be an env var) to the gateway. If the gateway fails to respond, or responds with a non-success response, the corresponding sip gateway should be set to inactive (we can leverage the is_active column that already exists in the database). When a gateway transitions from active to inactive due to a failure of an OPTIONS ping we should write an alert

[Megamuch]

I would like to add that a single failure might be too strict for disabling the gateway. I would keep a minimum of 5 missed pings so you really know it is down.

Another thing to think about is recovery. What happens is the gateway goes down for 1 hour and comes back up. Do we require a manual intervention into jambonz to re-activate the gateway?

[vdharashive]

@xquanluu and @davehorton can this feature be completed , its useful feature to keep the trunk up

[davehorton]

yes, this requires database changes so we deferred it to 0.8.6 which we will start shortly