Overview; Features And Functions; Physical Description - Meridian Nortel 1 Option 11C Technical Reference Manual

Page 514 of 544

Overview

Features and functions

Physical description

553-3011-100 Standard 14.00
NTAK93 D-channel handler interface
The NTAK93 provides D-channel handler interfaces required by the ISDN
PRI trunk. It performs D-channel layer 2 message processing and layer 3
preprocessing. It is a daughterboard that mounts to the NTAK09 1.5 Mb DTI/
PRI card or NTBK50 2.0 Mb PRI card using standoff reference pins and
connectors.
NTAK93 provides the following features and functions:
• D-channel or DPNSS interface
• special features included for LAPD implementation at DCH:
— system parameters are service changeable (system parameters are
downloaded from software)
— incoming Layer 3 message validation procedures are implemented
in the D-PORT firmware
— supported message units and information elements may be service
changed
— translation of the CCITT message types information elements into a
proprietary coding scheme for faster CPU operation
— convention of IA5-encoded digits to BCD-encoded digits for
incoming layer 3 messages for faster CPU operation
— self-test
— loopback
The DCH function can be located in the main and IP expansion cabinets. The
DTI/PRI card which carries a DCH daughterboard resides in the main and IP
expansion cabinets.
January 2002