1. 1 6/27/2015 22:41 CS575ATM Technology: Introduction1 Rivier College CS575: Advanced LANs ATM Technology: Introduction

2. 2 6/27/2015 22:41 CS575ATM Technology: Introduction2 Table of Contents Section 1 Introduction Section 2 ATM Layers and Protocol 2.1 Physical Layer 2.2 ATM Layer 2.3 ATM Adaptation Layer Section 3 Traffic Management Section 4 Signaling and Addressing Section 5 Private-Network-to-Network Interface (PNNI) Section 6 ATM LAN Emulation Section 7 IP Over ATM Section 8 Multiprotocol Over ATM (MPOA) Table of Contents

3. 3 6/27/2015 22:41 CS575ATM Technology: Introduction3 Section 1: ATM Technology Overview 0 Background 0 B-ISDN Services 0 What is ATM? 0 Why ATM? 0 How Does ATM work? 0 ATM Networks 0 ATM Interfaces 0 ATM and Legacy Networks 0 ATM Switches and Edge Devices 0 B-ISDN/ATM Protocol Reference Model 0 ATM Standards Organizations

4. 4 6/27/2015 22:41 CS575ATM Technology: Introduction4 Background 0 1984: ITU-T (CCITT) developed standards for ISDN 0 Types of ISDN (Integrated Services Digital Network) channels

5. 5 6/27/2015 22:41 CS575ATM Technology: Introduction5 Background (continued) 0 Two types of interfaces were specified: -Basic Rate Interface (BRI): 2B+D 144 Kbps (192 Kbps Interface structure gross bit rate) -Primary Rate Interface (PRI): 23B+D/30B+D 1.536/1.984 Mbps (1.544/2.048 Mbps gross bit rate)

6. 6 6/27/2015 22:41 CS575ATM Technology: Introduction6 Background (continued)

7. 7 6/27/2015 22:41 CS575ATM Technology: Introduction7 Background (concluded) 0 1985: ITU-T Study Group 13 (formerly the CCITT Study Group XVIII) began developing standards for Broadband ISDN (B-ISDN) 0 Objective: Define a B-ISDN transport technology for all types of traffic (voice, video, image, and data) for broadband services 0 1988: ITU-T selected Asynchronous Transfer Mode (ATM) as the switching and multiplexing technique for the B-ISDN 0 ATM was developed for B-ISDN, but it is also implemented in non- ISDN environments where very high data rates are required

8. 8 6/27/2015 22:41 CS575ATM Technology: Introduction8 B-ISDN Services Interactive Services Distribution Services Distribution Services with user Control Distribution Services without user Control Messaging Services Conversational Services Retrieval Services

9. 9 6/27/2015 22:41 CS575ATM Technology: Introduction9 What is Asynchronous Transfer Mode (ATM)? 0 Asynchronous Transfer Mode (ATM) is a connection-oriented, high-speed, low-delay switching and transmission technology that uses short and fixed- size packets, called cells, to transport information. 0 Using the cell switching technique, ATM combines the benefits of both circuit switching (low and constant delay, guaranteed capacity) and packet switching (flexibility, efficiency for bursty traffic) to support the transmission of multimedia traffic such as voice, video, image, and data over the same network. 5 octets 48 octets 53 octets Header Information

10. 10 6/27/2015 22:41 CS575ATM Technology: Introduction10 Why ATM? 0 International standard-based technology (for interoperability) 0 Low network latency (for voice, video, and real-time applications) 0 Low variance of delay (for voice and video transmission) 0 Guaranteed quality of service 0 High capacity switching (multi-giga bits per second) 0 Bandwidth flexibility (dynamically assigned to users) 0 Scalability (capacity may be increased on demand) 0 Medium not shared for ATM LAN (no degradation in performance as traffic load or number of users increases) 0 Supports a wide range of user access speeds 0 Appropriate (seamless integration) for LANs, MANs, and WANs 0 Supports audio, video, imagery, and data traffic (for integrated services)

11. 11 6/27/2015 22:41 CS575ATM Technology: Introduction11 ATM Network How Does ATM Work? H HH H H H H H Voice Video Data BISDN Services BISDN Services Reassembly User Applications Workstation Multiplexing Demultiplexing HHHH H H Segmentation

12. 12 6/27/2015 22:41 CS575ATM Technology: Introduction12 How Does ATM Work? (concluded) 0 ATM is connection-oriented -- an end-to-end connection must be established and routing tables setup prior to cell transmission 0 Once a connection is established, the ATM network will provide end-to-end Quality of Service (QoS) to the end users 0 All traffic, whether voice, video, image, or data is divided into 53- octet cells and routed in sequence across the ATM network 0 Routing information is carried in the header of each cell 0 Routing decisions and switching are performed by hardware in ATM switches 0 Cells are reassembled into voice, video, image, or data at the destination

13. 13 6/27/2015 22:41 CS575ATM Technology: Introduction13 ATM Networks 0 Public ATM Network: -Provided by public telecommunications carriers (e.g., AT&T, MCI WorldCom, and Sprint) -Interconnects private ATM networks -Interconnects remote non-ATM LANs -Interconnects individual users 0 Private ATM Network: -Owned by private organizations -Interconnects low speed/shared medium LANs (e.g., Ethernet, Token Ring, FDDI) as a backbone network -Interconnects individual users as the front-end LAN for high performance or multimedia applications

14. 14 6/27/2015 22:41 CS575ATM Technology: Introduction14 ATM Interfaces Private UNI Private ATM LAN Public UNI Public ATM Network Public ATM Network B-ICI Private ATM WAN P-NNI

15. 15 6/27/2015 22:41 CS575ATM Technology: Introduction15 Public ATM Network ATM and Legacy Networks Token Ring Token Ring FDDI Mainframe Computer Video Ethernet Mainframe Computer Edge Switch Ethernet File Server Private ATM Switch Edge Switch Edge Switch Edge Switch PBX Voice Private ATM Network FDDI

16. 16 6/27/2015 22:41 CS575ATM Technology: Introduction16 ATM Switches and Edge Devices 0 ATM Switches -ATM LAN switches -ATM Backbone switches -ATM WAN switches -ATM Central Office switches 0 ATM Edge Devices -ATM capable routers -ATM capable switches

17. 17 6/27/2015 22:41 CS575ATM Technology: Introduction17 Examples of ATM Workgroup Switches Marconi LE-155 ATM Workgroup Switch Cisco Systems LS-1010 ATM Workgroup Switch

18. 18 6/27/2015 22:41 CS575ATM Technology: Introduction18 Examples of ATM Backbone Switches Marconi ASX-1000 ATM Backbone Switch Marconi ASX-200 ATM Backbone Switch Marconi ASX-4000 ATM Backbone Switch

19. 19 6/27/2015 22:41 CS575ATM Technology: Introduction19 Examples of ATM WAN Switches Lucent GX 550 ATM Switch Cisco Systems Catalyst 8500 Multiservice Switch Router

20. 20 6/27/2015 22:41 CS575ATM Technology: Introduction20 Examples of ATM Edge Devices Marconi ES-3810 10/100 Ethernet Switch Cisco Systems Catalyst 5500 Switch Marconi ESX-3000 Campus Switch

21. 21 6/27/2015 22:41 CS575ATM Technology: Introduction21 B-ISDN/ATM Protocol Reference Model Source: Stallings: Data and Computer Communications

22. 22 6/27/2015 22:41 CS575ATM Technology: Introduction22 Appendix: B-ISDN Services 0 Retrieval Services -Video retrieval service =Entertainment =Remote education and training -High-resolution image retrieval service =Entertainment =Remote education and training =Professional image communications =Medical image communications -Document retrieval service =Mixed documents containing text, graphics, still and moving picture information, and voice annotations from archives or information centers

23. 23 6/27/2015 22:41 CS575ATM Technology: Introduction23 B-ISDN Services (continued) 0 Messaging services -Video mail service for the transfer of moving pictures and accompanying sound -Document mail service for mixed documents containing text, graphics, still and moving picture information, as well as voice annotations 0 Conversational services -Broadband videotelephony for the transfer of voice (sound), moving pictures, and video scanned still images and documents between two locations for =Tele-education =Tele-shopping =Tele-advertising -Broadband videoconference

24. 24 6/27/2015 22:41 CS575ATM Technology: Introduction24 B-ISDN Services (concluded) 0 Distribution services without user control -Document distribution =Electronic newspaper =Electronic publishing -Video distribution service =TV program distribution =HDTV program distribution =Pay-per-view TV program distribution 0 Distribution services with user control -Video broadcast for =Remote education and training =News retrieval =Video-on-demand

25. 25 6/27/2015 22:41 CS575ATM Technology: Introduction25 B-ISDN/ATM Standardization 0 ITU-T -ITU-T is the Telecommunications Standardization Sector of the International Telecommunication Union (ITU) -It is the new name for CCITT -It is in charge of setting network standards for public telecommunications -The ITU-T functions are carried out through study groups -Study Group 13 is responsible for setting standards (“I”, “Q”, and “F” Series Recommendations) for B-ISDN 0 ATM Forum (ATMF) -An international non-profit organization formed in September 1991 -Since then, it has expanded to include more than 750 voting members from ATM equipment vendors, service providers, carriers, and users

26. 26 6/27/2015 22:41 CS575ATM Technology: Introduction26 B-ISDN/ATM Standardization (concluded) -Objective: To accelerate the use of ATM products and services through interoperability specifications -The ATM Forum has a technical committee which works with other standards bodies such as ITU-T and ANSI to recommend new standards as well as to resolve any standards issues -The Technical Committee consists of a number of working groups to investigate different areas of ATM technologies -Working groups are responsible for producing technical specifications

27. 27 6/27/2015 22:41 CS575ATM Technology: Introduction27 W. Stalling, Local and Metropolitan Area Networks, 6 th edition, Prentice Hall, 2000, Chapter 11 References W. Stalling, Data and Computer Communications, 6 th edition, Prentice Hall, 2002, Chapters 11-12 A. Wu, Advanced Local Area Networks, Lectures & Slides, Rivier College, 2001.