Nortel Networks 1000 - Manual (Page 977)

Architecture 977
Table 413
DS-1 line interface pinout for NTBK04 cable (cont’d.)
From 50-pin
MDF
connector
To DB-15 Signal name Description
pin 49 pin 3 T1 receive tip from
network
pin 24 pin 11 R1 receive ring from
network
NTAK20 Clock Controller (CC) daughterboard
Digital Trunking requires synchronized clocking so that a shift in one clock
source results in an equivalent shift of the same size and direction in all
parts of the network.
The NTAK20 clock controller circuitry synchronizes the CS 1000E, CS
1000M Cabinet, and Meridian 1 PBX 11C Cabinetto an external reference
clock and generates and distributes the clock to the system. The CS
1000E, CS 1000M Cabinet, and Meridian 1 PBX 11C Cabinetcan function
either as a slave to an external clock or as a clocking master to the
network.
The NTAK20AD and NTAK20AA versions of the clock controller meet
AT&T Stratum 3 and Bell Canada Node Category D specifications. The
NTAK20BD and NTAK20BA versions meet CCITT stratum 4 specifications.
“NTAK20 Clock Controller daughterboard” (page 803)
ATTENTION
IMPORTANT!
Each Media Gateway that has a digital trunk must use a clock controller clocked
to an external reference clock.
If an IP Expansion multi-cabinet system is equipped with digital trunk cards, it is
mandatory that at least one trunk card is placed in the Main Option 11C cabinet.
A cabinet that has a digital trunk must use a clock controller.
Note: Clocking slips can occur between systems that are clocked from
different COs, if the COs are not synchronized. The slips can degrade
voice quality.
Digital Trunking requires synchronized clocking so that a shift in one
clock source results in an equivalent shift of the same size and direction
in all parts of the network. On Option 11C systems, synchronization is
accomplished with the NTAK20 clock controller circuit card.The Clock
Controller circuitry synchronizes the Option 11C to an external reference
clock, and generates and distributes the clock to the system. Option 11C
can function either as a slave to an external clock or as a clocking master.
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 02.06 Standard
27 August 2008
Copyright © 2003-2008 Nortel Networks
.