Question : asterisk questions

Hi all,

I have been asked to biuld an asterisk box as a gateway for all incomming telephone calls. I have to admit, I have no idea what an asterisk box is. I have read a few things on it but still don't have a good grasp.

What is asterisk? Is it a box the converts incomming PSTN calls to voice packets?

Also, I have read I need to install a TDM card. Can someone explain exactly what that does and which TDM card should I get?

Also, does asterisk with with SIP or h323 protocol? Where do I configure this within asterisk?

thanks

Answer : asterisk questions

Well that could be an advantage if the box is heavily loaded.  But you also have the advantage of shielding the PBX from a lightning strike as well.  If the circuit gets hit then just the gateway gets fried, not the PBX - hopefully ;)