Gateway conceptual question

[bobsonbemoi]

Hello everyone!
I'm new to VoIP and have a couple of questions.
I have CCM 4.1.2 up and running and have made calls from phone-to-phone and phone-to-PC (Cisco IP Communicator). I'm would like to learn how you can make a call from a Cisco IP phone to a person on the PSTN. I've read that I need a gateway and use H.323, MGCP.
So, my question is: can I use a switch to hook up my CallManager and IP Phones to a 2621 router, which is then connected to an old modem through one of its serial ports, and then the modem is connected to the PSTN. Can such a scenario work, and if so, I guess I would need an IOS image that supports something more than the regular stuff, what woud that IOS version be?
My second question is: is there some kind of PCI card you can buy that would turn a computer into a gateway?

 

[jneiberger]

In your first scenario, what are you expecting the modem to do? I don't understand why you'd put a modem in between your gateway and the PSTN. Regardless, if you can connect it so that the router/gateway gets dialtone then you should be fine.

There probably is H.323 software available from a third-party that would allow you to turn your PC into an H.323 gateway but I don't think I'd waste time trying to find it or trying to get it to work. If you already have the router, a 2-port FXO card is relatively cheap, especially if you get it used.

 

[bobsonbemoi]

I'm kinda interested in a cheap solution, say I don't have a router.
Are there any cheap H.323 hardware gateways I can go buy? I did a little research and stumbled upon the Sipura SPA-3000. It says it has 1-Port FXS and 1-Port FXO. What can be achieved with such a device?

 

[pndscm]

Check on eBay for some 2620 non-XM routers. They aren't too expensive and they'll work fine. You'll save money in the long run in the time you'll spend trying to get a 3rd party gateway to work with CallManager.