ATM and B-ISDN Notes for the lecture component ATM and B-ISDN Dr. Zhili Sun University of Surrey Guildford Surrey GU2 5XH. Telephone: 01483 87 9493 Fax: 01483 87 6011 Email: [email protected] Aims This lecture component is developed as part of the course module to provide you with information on advanced topics in ATM and Broadband Communications Technology. This component covers a range of topics that provides you with a comprehensive view of Asynchronous Transfer Mode (ATM) and Broadband Integrated Services Digital Network (B- ISDN) technology. The notes include the following main sections: • Introduction, • ATM Principle, • ATM standards, • B-ISDN Protocol Reference Model (PRM) for ATM, • ATM Switches, • ATM Interfaces and Networks, • Traffic Management and Control in ATM Networks If you have any comment or suggestion about this component, you are welcome to send it to me. © Dr. Z. SUN, University of Surrey 1 ATM and B-ISDN Table of Contents 1. INTRODUCTION .........................................................................................................................................................5 1.1 ATM FUNDAMENTAL CONCEPT.....................................................................................................................................5 1.2 BURSTY TRAFFIC ...........................................................................................................................................................5 1.3 ATM CELL.....................................................................................................................................................................6 1.4 ATM AS UNIVERSAL TRANSPORT NETWORKS ...............................................................................................................6 1.5 BROADBAND ISDN ........................................................................................................................................................6 1.6 CARRYING A BIT STREAM ..............................................................................................................................................6 1.7 CARRYING PACKET DATA ..............................................................................................................................................7 1.8 LAYERED ARCHITECTURE ..............................................................................................................................................7 2. ATM PRINCIPLE.........................................................................................................................................................7 2.1 ROUTING ........................................................................................................................................................................7 2.2 ATM RESOURCES MANAGEMENT..................................................................................................................................7 2.3 ATM CELL IDENTIFIERS.................................................................................................................................................8 2.4 THROUGHPUT.................................................................................................................................................................8 2.5 QUALITY OF SERVICE.....................................................................................................................................................8 2.6 USAGE PARAMETER CONTROL.......................................................................................................................................8 2.7 FLOW CONTROL .............................................................................................................................................................8 3. ATM STANDARDS ......................................................................................................................................................8 3.1 B-ISDN PROTOCOL REFERENCE MODEL (PRM) FOR ATM...........................................................................................8 3.2 PHYSICAL LAYER............................................................................................................................................................9 3.2.1 Two Sublayers .....................................................................................................................................................10 3.2.2 155 Mbps, SONET STS-3c...................................................................................................................................11 3.2.3 44 Mbps, DS3 ......................................................................................................................................................12 3.2.4 155 Mbps, 8B/10B Coding ..................................................................................................................................14 3.2.5 100 Mbps, 4B/5B Coding ....................................................................................................................................14 3.2.6 1.544 Mbps DS-1.................................................................................................................................................15 3.2.7 2.048 Mbps E1.....................................................................................................................................................15 3.2.8 34 Mbps E3..........................................................................................................................................................16 3.2.9 6.312 Mbps J2 .....................................................................................................................................................17 3.2.10 25.6 Mbps UTP-3 ..............................................................................................................................................17 3.2.11 Other Possibilities .............................................................................................................................................17 3.3 ATM LAYER ................................................................................................................................................................18 3.3.1 ATM UNI Cell......................................................................................................................................................19 3.3.2 Why 53 Bytes? .....................................................................................................................................................19 3.3.3 Virtual Connections.............................................................................................................................................21 3.3.4 Virtual Paths and Virtual Channels ....................................................................................................................23 3.3.5 Cell Loss Priority (CLP)......................................................................................................................................23 3.3.6 Payload Type Identifier .......................................................................................................................................24 3.3.7 Generic Flow Control..........................................................................................................................................24 3.3.8 Header Error Check ............................................................................................................................................24 3.4 ATM ADAPTATION LAYER (AAL)...............................................................................................................................25 3.4.1 Two Sublayers .....................................................................................................................................................25 3.4.2 Broadband Services and Applications.................................................................................................................25 3.4.3 AAL type 1 for Class A ........................................................................................................................................26 3.4.4 AAL2 for Class B .................................................................................................................................................28 3.4.5 AAL 3/4 for Classes C & D..................................................................................................................................28 3.4.6 AAL5 for Classes C & D......................................................................................................................................29 4. ATM SWITCHES .......................................................................................................................................................30 4.1 QUEUEING DISCIPLINES IN AN ATM SWITCHING ELEMENT: ..........................................................................................30 4.2 PERFORMANCE ISSUES .................................................................................................................................................32 4.2.1 Throughput ..........................................................................................................................................................32 4.2.2 Connection Blocking Probability ........................................................................................................................32