Telephony question

You could configure Asterisk

to do that assuming that "certain circumstances" is something that it can be made aware of.

If VOIP is your wish, then you don't need much in the way of routing. A small PBX with verified account codes, a VOIP ATA and a PC to capture the data and you're good to go. Set the PBX for trunk-to-trunk connections, put your verified account codes in the bins, connect the serial port to capture the data and let your customers dial in on one line and out on another. You don't care what or where they dial, since VOIP will handle the billing at a flat rate or international rate, and your SMDR captures the account code and number dialed.

Carl Navarro

Asterisk is not really black box, or actually it could be if you are not a techie. My guestimation is that the OP is looking for a readily made system. The machine you are looking for is called an ACD (Automatic Call Distribution) possibly with IVR (Interactive Voice Response) features. This would allow you to route calls from one point to another based on things like time, number info or input by the callee.

Depending on the scale of things you might want to check IA

however there are many more vendors. Just google for IVR...

Asterisk is an option. You'd need somebody to config it. Check the VoIP wiki

for commercial support.

Arnold.

Now what you really want...

is sometimes called a "call diverter". There are a number available from various manufacturers. They just receive a call on one line, then dial a preprogrammed number on a second line. When the second line is answered, then it connects the first line to complete the call. It will disconnect when the parties hang up. Some are remotely programmable. You just need to make the second line feed into a Vonage box or whatever voip line you choose.

make one called the Rad-Amp You can also do a google search on "call diverter" and sometimes spelled "divertor"

Charles