Voip via speed fusion with different ISP


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?


What are the bandwidth and type of internet link of all locations?

From the Web Admin, have you checked the Status > SpeedFusion? What are the values of latency and packet drop?


We have not been running both enabled for a long time. To answer your question I changed both ends of the VPN to use both WAN as priority 1. I am showing 60ms on the cable modem, and 110ms on DSL. It looks the same on both ends, and is steady. I assume speed fusion buffers and adapts to the different latency, which is unfortunately a reality of life with different internet sources. VOIP does not tolerate that well. If I could leave the blended VPN up, but prioritize certain ports to one path, it should take care of the problem.


Hi Don- Do you have QoS for SIP and RTP enabled on all the Balances?


On the 380 main office:

apply same settings to all users
streaming applications = LOW
file sharing/transfer = LOW
http = LOW
5060-5065 TCP = HIGH
5060-5065 UDP = HIGH
10000-20000 UDP = HIGH
5038 TCP = NORMAL (5038 is a control port for the asterisk servers to talk to each other)
DSL/Cable optimization is enabled

On the 210 remote office:
all supported streaming applications = NORMAL
all supported voip protocols = HIGH
DSL/Cable optimization is enabled