Functional Description - Nortel Enterprise 1000 Reference Manual

Page 168 of 236

Functional description

553-3023-211 Standard 1.00 June 2001
NTAK79 2.0 Mb PRI card
The NTAK79 card does not support the NTBK51 downloadable D-channel
handler daughterboard.
The NTAK79 card is installed only in the Media Gateway. It is not supported
in the Media Gateway Expansion. Up to three digital trunk cards are
supported in each Media Gateway. The NTAK79 card can be installed in
Slot 1, 2, and 3 of the Media Gateway.
Each Media Gateway that has a digital trunk must have a
clock controller clocked to an external reference clock.
Note: Clocking slips can occur between Media Gateways that are
clocked from different COs, if the COs are not synchronized. The slips
can cause degraded voice quality.
The NTAK79 card provides the following features and functions:
• recovery of the 2.048 kbps data by the CEPT receiver, at signal levels
which have been attenuated by up 10 dB
• control of CEPT line density using HDB3 which provides 64 kbps clear
channel
• performance monitoring of the receive carrier by means of Bipolar
Violations (BPV), Slips, CRC-4 (CRC), and Frame Bit Errors (FBER)
• monitoring of receive carrier alarms including AIS, LOS, and RAI
• transmission of remote alarm when instructed
• slip-buffering receive messages
• supporting National and International bits in time slot 0
• on-board clock controller
• onboard D-channel interface
• 32 software-selectable Tx & Rx Pad values
IMPORTANT