Since you mentioned the brand, I am running advanced voip billing.
That is the name.
After listening to the horror stories of $35.000 and still not working with a sysmaster, I feel fortunate.
This guys installed the system remotely without a cent, charge based on the ammount of ports, and the whole billing plus CDR server for a system with 24 ports still under $3000.00 dollars.
Not fency, but works. And the heck, still $27.000 ahead of the fellow complaining about sysmaster.