Nortel 1000 Installation And Commissioning Manual page 199

Shelf slot assignments
For cabinet systems, the NTAK09 DTI/PRI card can be placed in main and
expansion cabinets in any single card slot given in
assignments for NTRB21, NTAK09, and NTAK20" (page
Digital trunk cards are not supported in the Media Gateway Expansion.
Figure 77
NTAK09 DTI/PRI circuit card
NTAK20 Clock Controller (CC) daughterboard
Digital Trunking requires synchronized clocking so a shift in one clock source
results in an equivalent shift of the same size and direction in all parts of the
network. Synchronization is accomplished with the NTAK20 clock controller
circuit card in each Main and IP expansion cabinet/Media Gateway.
IMPORTANT!
Every Small System cabinet or Media Gateway that contains a digital trunk must
contain a clock controller.
If a Small System is equipped with digital trunks, it is recommended that at least
one digital trunk be placed in the main cabinet.
Copyright © 2003-2007, Nortel Networks
.
Nortel Communication Server 1000
ISDN Primary Rate Interface Installation and Commissioning
NN43001-301 02.03 Standard
Release 5.5 7 December 2007
Hardware description 199
ATTENTION
Table 74 "Shelf slot
202).