I have an office that requires a higher capacity connection and in an effort to save money we have ordered a second Time Warner cable internet connection into the building and we have used a Watchguard XTM515 to aggregate the 2 cable modems. I have also weighed them 1:1 since both connections are 50/5.
There seems to be one negative side effect of this and it's interfering with our VoIP system. We have an Altigen server that's collocated in a data center that's responsible for this particular office. The phones will just randomly drop their registration and then they are out of commission of course. When initially implemented this seemed to work fine for days and then all of a sudden I was notified that randomly phones will unregister and stay down for long periods of time. There are about 100 other phones on that server and all of them are working just fine. Also it's a pretty standard configuration on these phones as well. The process of distributing internet access over these 2 connections seems to be causing the issue. The XTM515 has enough muscle under the hood to handle this office, it never runs out of resources. The solution here would be to just send all the VoIP traffic strictly through one of the interfaces but does anybody have any ideas as to how to do this? I thought about implementing a SIP ALG policy but as I'm watching traffic I can't see any SIP traffic (We are using SIP trunks) so that policy may not work. Please advise.