13th February 2006 at 18:34
#30713
MikeM
Guest
DID is Direct Inward Dialing. These are the phone numbers that are dialed to call in on a line.
All this means is say you have an ISDN line (does not matter if T1 or E1) and that is going to connect to your PBX or gateway. You can have many DID numbers, or numbers that people will dial to call in on the ISDN line.