Lucent Technologies MERLIN LEGEND Release 6.0 Network Reference Manual page 54

MERLIN LEGEND Communications System Release 6.0
Network Reference 555-660-150
1 Introduction
Tandem Trunking and Tandem Switching
To ensure proper transmission quality, the path of a network call should
include no more than two spans of analog tie trunks. The network in
1–4
When an outside dial-plan routed PRI call with ANI arrives on System A or
B, ANI calling party information travels to a destination extension on
Systems A, B, or C. System D users can receive this information only from
their PRI to the PSTN.
System D is located in close geographic proximity to System C. This allows
System D to use the PSTN for 2B video calls with System C at up to 128
kbps without incurring high toll costs. However, because of the tie
connections, intersystem video and intersystem high-speed data calls are
not supported to and from System D.
In this configuration, System B uses more of its 80-line capacity for network
trunks than do Systems A, C, and D.
The configuration illustrated in
disadvantages, is suitable for many businesses, particularly when one or more
systems do not require PRI features. For example, a system linked by tandem tie
trunks may be perfectly adequate for a warehouse or other operations group.
includes one such span, between Systems C and D.
Figure 1–4, with its advantages and
Issue 1
February 1998
Page 1-12
Figure