[asterisk-users] What do I need to connect landline calls without telephony hardware?

[don rhummy]

> > If I already have VOIP, can I use them or is it a
> special kind of service I'd need?
> 
> explain "already have voip" ?

I have a VOIP box/modem and VOIP service at home. My phone is hooked into that. Can I use that service with my asterisk or do I need to purchase something else from the VOIP provider?