5-12 ELECTRONIC TANDEM NETWORK (ETN) THROUGH THE ETN AND PNA PACKAGES
_ ___________________________________________________________________________________________________________________________
_ ___________________________________________________________________________________________________________________________
_ ___________________________________________________________________________________________________________________________
(1)
8-346-1234
(2)
346-1234
SO
(3)
346-1234
SO
346
1234
SDN
DIRECT
ACCESS
PNI
ETN
(7)
1234
(6)
ROUTE
CALL
AT&T SDN
(5) BILLING &
ROUTING
INSTRUCTIONS
(4) DATA BASE
QUERY
NCP
ACP ACP
Figure 5-7. Call Flow ETN - to - SDN
7. The egress ACP routes the call to the destination switch, which rings the terminal indicated by the
extension number it receives.
Release Link Trunk Networks — CAS and ACD
Centralized Attendant Service (CAS) and Automatic Call Distribution (ACD) are features that use release
link trunks (RLTs) in their operation. Like tie trunks, RLTs connect communications systems. Unlike tie
trunks, which carry calls from their initiation to completion, RLTs provide only a temporary service for the
call. That is, RLTs carry calls from their originating switches to the switch where the attendants or agents
are located. Upon receiving the call, the attendant or agent identifies the call destination, returns the call to
the switch of origin for routing and processing, and, then, disengages the RLT, readying it for another call.
Release link trunk network software and ETN software can work together in the same network without
interference. However, the ETN (Standard Network) package or the Private Network Access package is not
required for release link trunk network operation.
For Centralized Attendant Service and Automatic Call Distribution capacities and administration details,
refer to DEFINITY Communications System, Generic 2 and System 85, Feature Descriptions (555-104-
301), DEFINITY Communications System, Generic 1 and System 75, and System 75 XE, Feature
Descriptions (555-200-201), and DEFINITY Communications System, System 75 and Generic 1.1 (555-
204-654).