Avaya M-ACCF/SF manual Network Layer Concepts ATM & ATM Adaptation, Layered Network Architecture

Chapter 1 Overview

Network Layer Concepts — ATM & ATM Adaptation

This Section describes the following concepts behind the network layer architecture of a typical ATM network:

•The Layered Network Architecture

•ATM Adaptation Layer (AAL)

•Asynchronous Transfer Mode (ATM) Layer

•Physical Layer

The Layered Network Architecture

Asynchronous Transfer Mode (ATM) is one part of the layered network architecture. This architecture is shown in Figure 1.8.

Each of the layers is discussed in turn; starting with the Upper Layer and working down to the Physical Layer.

Figure 1.8 Network Layer Architecture

ULPPDUs

LAN Emulation

Frames

AAL5 PDUs

ATM Cells

SONET or SDH

frames

media

Key
	Logical flow
	Physical flow
PDUs	Protocol Data Units

Avaya M770 M-ACCF/SF ATM Access Modules User’s Guide 15