Using DID

I want to get an Asterisk-based system to replace our current Nortel system. I having a little trouble trying to find out what kind of card I need to be able to handle DID. We currently have a number of analog lines coming in plus four DID trunks. I know that if we went to PRI that it would incorporate the lines and the DID trunks. I’m assuming that a PRI card would also handle the DID trunks OK. I know that the DID trunks are not FX0 or FXS. Can anybody enlighten me as to what I’m looking for? Thanks.

I would recommend replacing your DID trunk group with DID VoIP services. Port the range of dialable numbers to any of the VoIP origination service providers. They typically offer pricing based on the number of dialable numbers and on the number of concurrent calls (virtual trunks) supported. You’ll probably find an offering that is functionally equivalent to your present arrangement at a far lower cost. Your DID calls will reach your Asterisk server as SIP transactions. Your dialplan will route these calls to the appropriate extensions or other call-processing functions.

I do this with and with but shop around; there are plenty of similar offerings.