Tools to test asterisk, freepbx and a2billing system

dear sir,

we’re using asterisk as PBX server, freepbx as GUI and a2billing as billing engine. at the moment, we’re trying to test the IP PBX system and Calling Card system with the inbound DID numbers and outbound termination between the services providers and our systems.

at the moment, the IP PBX systems is hosted in a office, behind a NAT router, through a modem (with a static public IP address assigned by the ISP) to connect to the Internet.

can anyone help to recommend the good testing tools (open source and commercial ones) for fully testing the IP based systems?

your help is much appreciated.

kind regards,
david su

I do not know any dedicated tools for these sorts of testing.

I would say that the best way for testing this is to make a large ammount of test calls and check the programs output in much detail.