Nortel Networks 553-3001-211 manual Appendix a Lapb Data Link Control protocol, Contents

894

Page 889 of 894

Appendix A: LAPB Data Link Control protocol

Contents

This section contains information on the following topics:

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 889

Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 889

Frame structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 890

LAPB balanced class of procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . 891

Commands and responses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 892

Description of procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 893

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

Circuit Card Description and Installation