Lucent Technologies MERLIN LEGEND Release 5.0 Feature Reference page 154

MERLIN LEGEND Communications System Release 5.0
Feature Reference 555-650-110
Features
Centrex Operation
Figure 4.
Limited Centrex
With limited Centrex service, users depend principally on the communications
system's features, but a limited number of prime lines can be used to access the
CO Centrex. There are two cases that are particularly suitable for limited Centrex:
Centrex lines/trunks may be less expensive than other lines.
Different users may have different needs for telephone service, so that
some users benefit more from Centrex while other users benefit more from
direct use of the communications system.
In the limited Centrex configuration, some extensions may have prime lines while
other extensions access the prime lines through a pool. Extensions can also be
assigned ground-start, tie, or DID lines, which is not possible in full Centrex.
Telephones without prime lines can use a Pool button to access Centrex facilities
or may use an SA button to access pooled facilities by dialing an access code.
Once connected to a pool, users may dial other Centrex extensions or dial an
access code for outside calls. Outside calls made by using an SA button to
access a pool require two access codes for outside calls, one for the pool and one
for outside lines on Centrex.
For limited Centrex operation, the communications system must be in Key or
Hybrid/PBX mode. The total system operates on three levels, as shown in
Central Office Central Office
(External Calls) (External Calls)
Centrex Service Centrex Service
• 4-digit Centrex Calls • 4-digit Centrex Calls
• Use of Centrex Features • Use of Centrex Features
MERLIN LEGEND
Communications System
• 2, 3, or 4-digit intercom
• Key Mode Features
Full Centrex Service
3
Issue 1
June 1997
Page 122