Functional Description - Nortel Enterprise 1000 Reference Manual

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Functional description

553-3023-211 Standard 1.00 June 2001
NTBK50 2.0 Mb PRI card
to the on-board NTAK79 DCHI. The NTBK51 DDCH daughterboard
provides support for protocols based on the MSDL platform.
The NTBK50 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 NTBK50 card can be installed in Slots 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.
NTBK50 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 to 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
• support of National and International bits in time slot 0
• clock controller daughterboard
• D-channel interface daughterboard
• Downloadable D-channel handler daughterboard
IMPORTANT