With firewall rules enabled there is no ring tone on any outbound calls, only inbound calls.
Watching the network interface on the free switch server with tcp dump:
- firewall off - UDP stream bi-directional between freeswitch and the endpoint
- firewall on - UDP stream one-way (to freeswitch) from the endpoint
As there are no outbound rules from the server, this would lead to believe it's a freeswitch problem - but how so?
BTW - with the firewall enabled in-call voice is fine (ie: two way). It's only ring tone that's affected.