Nortel Networks Circuit Card 311 User Manual

Page 1077

Advertising
background image

Architecture

1077

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 Cabinet to an external reference
clock and generates and distributes the clock to the system. The CS 1000E,
CS 1000M Cabinet, and Meridian 1 PBX 11C Cabinet can 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 903)

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.

The NTAK20AA version of the clock controller meets AT&T Stratum 3 and
Bell Canada Node Category D specifications. The NTAK20BA version meets
CCITT stratum 4 specifications.

"Electrical specifications" (page 1005)

ATTENTION

IMPORTANT!

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.

Nortel Communication Server 1000

Circuit Card Reference

NN43001-311

01.04

Standard

Release 5.0

23 May 2008

Copyright © 2003-2008, Nortel Networks

.

Advertising