We run a 380 at the main office, and a 210 at each of two remotes offices. Each office is supplied by a cable and DSL internet provider. They are not the same providers at each location. Set up speed fusion with blended VPN in a star configuration, with vpn links between each. Three legs, including 210 to 210.
We run Asterisk servers at each location, which talk to each other to provide extension to extension dialing among the offices. We had unpredictable results for calls between offices. Choppy calls, dropped calls, poor voice quality. Sometimes good, sometimes not so good.
I noticed that when one of the internet providers was down, the call problems went away. I tried setting the speed fusion to use one WAN as #1, and the other as #2 backup. Previously had #1 priority on both. The call problems went away. We’ve been running that way for over a year with no problem. If one of the links goes down we do temporarily lose the vpn, but it reconnects using the other side without user action. We also do not have the benefit of increased vpn bandwidth that a bonded vpn would provide.
I speculate that the different internet sources have different latency (DSL is slower), so depending on the internet provider’s load the packets on one channel arrive out of sync with the other. Just my speculation, I have no way to verify that. All I know is that if I set speed fusion to #1 priority for both WAN ports, the call problems return immediately. To be fair I have not tried it using both WAN for vpn since the 4.x.x firmware days. Maybe this is not a problem with 5.x.x firmware. We are on 5.4.9 now.
I have been hoping for the ability to make outbound rules which prioritize certain ports to one side of the vpn. Asterisk uses ports 5060-5064, and 10,000-20,000. If I could run the blended vpn, but prioritize those ports to one side of the vpn, I think the phone would be ok, but we would have the benefits of the blended vpn (bandwidth and uninterrupted failover).
Any thoughts on that?
