Nortel BCM50 Configuration Manual page 35

Figure 2 DID system
Target line mapped to
DN (4006)
Incoming calls
1 DID trunks are assigned to be auto-answer.
Note: PRI lines are automatically set to auto-answer.
2
All DNs are assigned target lines.
3 A caller dials a system code and a DN. In the example shown above, it might be 769-4006.
4 The call comes into the trunk, which answers and maps the call on the target line assigned to
the matching received digits.
5 The DN assigned to that target line rings.
You can assign unanswered or busy telephones to Call Forward to another DN, such as a
designated attendant or a voice-mail system.
Basic telephony routing
In a basic configuration, simple access codes (for example Line Pool Codes) are used to access the
PSTN network.
In a more complex configuration, more advanced destination codes are required to access multiple
PSTNs, private network resources, and remote nodes. Access to these resources enables advanced
features, such as tandem routing.
Target line mapped to
DN (4005)
Target line mapped to
DN (4007)
Chapter 2 System telephony networking overview
Target line mapped to
DN (4008)
CO DID line
i.e. 769
with range of call
numbers (4005 to
4020)
Networking Configuration Guide
35