With Communication Manager, you can directly dial various extensions such as a Vector Directory Number (VDN), a hunt group, an agent, or a login ID. You can assign each extension to a split as a Direct Inward Dialing (DID) extension. With DID processing, incoming trunks do not connect the CO directly to the phone of the employee. Instead, the communication server pools the incoming trunks and the employee phones share the pool of trunks. Extension numbers serve as the final digits of employee phone numbers for incoming calls, that is, the CO assigns a 2-digit, 3-digit or 4-digit prefix to a trunk group. When a caller dials a 7-digit employee phone number, call processing is as follows:
The CO processes the prefix of the dialed number and seizes a trunk in the trunk group that is assigned the prefix.
The CO passes the remaining digits of the dialed number to Communication Manager.
Communication Manager recognizes the remaining digits as an employee extension number and sends the call to that extension.
Note:
Automatic-in trunk groups carry calls only to the split, whereas DID trunk groups carry calls to any extension identified in Communication Manager, not just to a split.
