Nortel Networks 311 Tx Direction, Rx Direction

894 NTAK102.0 Mb DTI card

Carrier interface

Tx Direction

The HDB3 encoded multiplexer output is sent to the output selector,which

selects the PCM/Data output or the looped around far end data. The HDB3

is converted from digital to AMI and sent to the carrier. A transformer

provides isolation and impedance matching (75 ohms or 120 ohms).

The HDB3 encoded multiplexer outputis fed to the output selector, which

selects the PCM/Data output or the looped around far end data. The

HDB3 is converted from digital to AMI and fed to the carrier. A transformer

provides isolation and impedance matching (75 ohms or 120 ohms).

The HDB3 encoded multiplexer output is sent to the output selector,which

selects the PCM/Data output or the looped around far end data. The HDB3

is converted from digital to AMI and sent to the carrier. A transformer

provides isolation and impedance matching (75 ohms or 120 ohms).

Rx Direction

The AMI data of the carrier is converted to digital and fed to the input

selector as well as the output selector for far end loopback. Clock recovery

circuitry within the receiving device extracts the2.0 MHz clock. This clock

generates the frame and multiframe count and sends them to the clock

controller as a reference.The AMI data of the carrier is converted to digital

and fed to the input selector as well as the output selector for far end

loopback. Clock recovery circuitry within the receiving device extracts the

2.0 MHz clock. This clock is used to generate the frame and multiframe

count and is sent to the clock controller as a reference.

The AMI data of the carrier is converted to digital and fed to the input selector

as well as the output selector forfar end loopback. Clockrecovery circuitr y

within the receiving device extractsthe 2.0 MHz clock. Thisclock generates

the frame and multiframe count and sends them to the clock controller as a

Clock controller interface

The recovered clockfrom the external digital facility is provided to the clock

controller through the backplane-to-clock controller interface. Depending

upon the state of the clock controller (switchedon or off), the clock controller

interface, in conjunction with software, enables or disables the appropriate

reference clock source.

The clock-controller circuitry on NTAK10is identical to that of the NTAK20.

While several DTI/PRI packs can existin one system, only one clock

controller can be activated. All other DTI/PRI clock controllers must be

switched off.

Nortel Communication Server 1000

Circuit Card Reference

NN43001-311 01.04 Standard

Release 5.0 23 May 2008