Nortel Networks Circuit Card - Manual (Page 785)

Page 785 of 906
Circuit Card Description and Installation
790
NTBK51 Downloadable D-channel
Handler daughterboard
Contents
This section contains information on the following topics:
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 785
Physical description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 786
Functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 787
Download operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 789
Introduction
The NTBK51 daughterboard provides Downloadable D-channel Handler
(DDCH) interfaces based on the Multipurpose Serial Data Link (MSDL). The
DDCH provides a single purpose full-duplex serial port capable of
downloading the D-channel application and base software into the card.
The NTBK51 provides the following features and functions:
• ISDN D-channel related protocol
• Selftest
• Loopback
• D-channel loadware including:
— management and maintenance
— LAPD- software for data link layer processing