Nortel Networks 1000 User Manual
Page 1009
1009
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Appendix
LAPB Data Link Control protocol
Contents
This section contains information on the following topics:
“LAPB balanced class of procedure” (page 1011)
“Commands and responses” (page 1011)
“Description of procedure” (page 1012)
Introduction
This chapter describes the LAPB Data Link Control protocol used with the
QPC513 ESDI card. The protocol is a subset of the HDLC procedures
which are described in International Organization for Standardization
procedures ISO 3309-1979 (E), ISO 4335-1979 (E) and appendices 1 and
2, and ISO 6256-1981 (E). Refer to these procedures for complete LAPB
details. Applications which use an ESDI port in synchronous mode must
conform to the following requirements.
Operation
Circuit Switch Equipment transfers data to the QPC513 in blocks
consisting of 1 to 128 eight-bit octets. Each block is processed in
accordance with the LAPB subset of the HDLC protocol and transmitted
serially to the line at a rate determined by the downloaded parameters.
The QPC513 card receives data serially from the line, packaged in LAPB
information frames. After determining that a block is error free, the data is
supplied to the Circuit Switch Equipment as a block.
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311
02.06
Standard
27 August 2008
Copyright © 2003-2008 Nortel Networks
.