Transfer Mode Switching Asynchronous

Asynchronous_Transfer_Mode_Switching Asynchronous Transfer Mode (ATM) is an International Telecommunication Union-Telecommunications Standards Section (ITU-T) standard for cell relay wherein information for multiple service types, such as voice, video, or data, is conveyed in small, fixed-size cells. ATM networks are connection-oriented. This article provides summaries of ATM protocols, services,and operation. Figure: A Private ATM Network and a Public ATM Network Both Can Carry Voice, Video, and Data Traffic illustrates a private ATM network and a public ATM network carrying voice, video, and data traffic. Guide Contents Internetworking Basics LAN Technologies WAN Technologies Internet Protocols Bridging and Switching Routing Network Management Voice/Data Integration TechnologiesWireless Technologies Cable Access Technologies Dial-up Technology Security Technologies Quality of Service Networking Network Caching Technologies IBM Network Management Multiservice Access Technologies

Contents
• 1 Figure: A Private ATM Network and a Public ATM Network Both Can Carry Voice, Video, and Data Traffic • 2 Standards • 3 ATM Devices and the Network Environment ♦ 3.1 ATM Cell BasicFormat ◊ 3.1.1 Figure: An ATM Cell Consists of a Header and Payload Data ♦ 3.2 ATM Devices ◊ 3.2.1 Figure: An ATM Network Comprises ATM Switches and Endpoints ♦ 3.3 ATM Network Interfaces ◊ 3.3.1 Figure: ATM Interface Specifications Differ for Private and Public Networks • 4 ATM Cell Header Format ♦ 4.1 Figure: An ATM Cell, ATM UNI Cell, and ATM NNI Cell Header Each Contain 48 Bytes of Payload ♦ 4.2ATM Cell Header Fields • 5 ATM Services ♦ 5.1 ATM Virtual Connections ◊ 5.1.1 Figure: VCs Concatenate to Create VPs • 6 ATM Switching Operations • 7 ATM Reference Model ♦ 7.1 Figure: The ATM Reference Model Relates to the Lowest Two Layers of the OSI Reference

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Asynchronous_Transfer_Mode_Switching Model ♦ 7.2 The ATM Physical Layer ♦ 7.3 ATM Adaptation Layers: AAL1 ◊ 7.3.1Figure: AAL1 Prepares a Cell for Transmission So That the Cells Retain Their Order ♦ 7.4 ATM Adaptation Layers: AAL2 ♦ 7.5 ATM Adaptation Layers: AAL3/4 ♦ 7.6 ATM Adaptation Layers: AAL5 • 8 ATM Addressing ♦ 8.1 Subnetwork Model of Addressing ♦ 8.2 NSAP Format ATM Addresses ◊ 8.2.1 Figure: Three Formats of ATM Addresses Are Used for Private Networks ♦ 8.3 ATM Address Fields • 9 ATM Connections • 10 ATMand Multicasting • 11 ATM Quality of Service • 12 ATM Signaling and Connection Establishment ♦ 12.1 The ATM Connection-Establishment Process ♦ 12.2 Connection-Request Routing and Negotiation ◊ 12.2.1 Figure: ATM Devices Establish Connections Through the One-Pass Method • 13 ATM Connection-Management Messages • 14 PNNI • 15 Integrated Local Management Interface ♦ 15.1 Table: Commonly Used VCIValues • 16 LAN Emulation ♦ 16.1 Figure: ATM Networks Can Emulate a Physical LAN ♦ 16.2 The LANE Protocol Architecture ◊ 16.2.1 Figure: LANE Protocol Architecture Can Be Implemented in ATM Network Devices ♦ 16.3 LANE Components ◊ 16.3.1 Figure: An ELAN Consists of Clients, Servers, and Various Intermediate Nodes ♦ 16.4 LAN Emulation Connection Types ◊ 16.4.1 Figure: LANE Data Connections Use a Seriesof VCLs to Link a LAN Switch and ATM Hosts ◊ 16.4.2 Figure: LANE Control Connections Link the LES, LECS, LAN Switch, and ATM Host ♦ 16.5 LANE Operation ◊ 16.5.1 Initialization and Configuration ◊ 16.5.2 Joining and Registering with the LES ◊ 16.5.3 Finding and Joining the BUS ◊ 16.5.4 Data Transfer • 17 Multiprotocol over ATM ♦ 17.1 Figure: A Comparison of Inter-ELAN Communications Without (Part A)and with (Part B) MPOA • 18 Review Questions • 19 For More Information

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Figure: A Private ATM Network and a Public ATM Network Both Can Carry Voice, Video, and Data Traffic

Standards
ATM is based on the efforts of the ITU-T Broadband Integrated Services Digital Network (B-ISDN) standard. It was originally conceived as a high-speed...