Transcript ATM
Asynchronous Transfer Mode (ATM): Basic GROUP 13 Group Member ™ MOHD FARRIZ FAIRUZZAMAN AZME WET020089 ™ MOHD KHAIRI SHAPIEE WET020090 ™ MOHD RASMANIZAN AWANG WET020092 ™ NIK MOHD JEFRY JUHARI WET020106 ™ NURUL IHSAN BAHARUDIN WET020135 Topics ATM History ATM Concepts ATM Architecture Summary History of ATM Asynchronous Transfer Mode (ATM) is cell relay protocol Designed by ATM Forum and adopted by the ITU-T and B-ISDN Allow high-speed interconnection of all the world’s networks ATM can be thought of as the “highway” of the information superhighway ITU-T : International Telecommunations Union-Telecommunation Standardization Sector B-ISDN: Broadband Integrated Services Digital Network ATM Technology One International Standard Both LAN and WAN Technology QoS Voice/Data/Video Mb Gb QoS = Quality of Service A ATM Basic Concepts Negotiated Service Connection End-to-end connections, called virtual circuits Traffic contract Switched Based Dedicated capacity Cell Based Small, fixed length A Negotiated Service Connection Traffic Contract Parameters Traffic Characteristics Peak Cell Rate Sustainable Cell Rate Quality of Service Delay Cell Loss Virtual Connection 1-QOS A Virtual Connection 1-QOS B Virtual Connection 1-QOS b The ATM Cell Header Payload 5 Bytes 48 Bytes 53 Bytes Small Size 5 Byte Header 48 Byte Payload (user information – may be less than 48 bytes) Fixed Size Header contains virtual circuit information Payload can be voice, video or other data types A ATM System Architecture End Station Switch End Station Voice Data Video Voice A A A T L M P H Y P A H T Y M Cells P H Y P A H T Y M A A L Data Video Adaptation Layer (AAL): Inserts/extracts information into 48 byte payload ATM Layer: Adds/removes 5 byte header to payload Physical Layer: Converts to appropriate electrical or optical format ATM Adaptation Layer AAL Types 1 Circuit Emulation -Constant Bit Rate (CBR) 2 Low Bit Rate Voice (Real Time) 48 Bytes -Variable Bit Rate (VBR) 3/4 5 Time Invariant Data “Simple” Data Provides Mapping Of Applications To ATM Service Of The Same Type Segments/Reassembles Into 48 Payloads Hands 48 Byte Payloads To ATM Layer A ATM Layer 48-Byte Payloads From AAL 5-Byte Header } 53-Byte Cell To Physical Layer Header Contains Virtual Path and Channel Identifiers Adds/Removes Header To 48 Byte Payload Header Contains Connection Identifier Multiplexes 53 Byte Cells Into Virtual Connections Sequential Delivery Within A Virtual Connection A Physical Layer Speed Matching and Framing Cable Plants Uses Existing Media Wide Range of Speeds Twisted Pair Coax Transmission Frame Fiber LAN, MAN, WAN -Multimode Compatibility -Single Mode A Advantages of ATM Accommodation of mixed media traffic Simplified Network Infrastructure ATM Scalability & Flexibility Simplified Network Infrastructure ATM Switch ATM Switch WAN Campus/MAN ATM ATM ATM E-net Device ATM ATM ATM TR LAN/Desktop Server Server LAN=MAN=WAN Device E-net TR Accommodation of Mixed Media Video Data Voice Standards STANDARDS GROUPS Customers ATM Forum 900 Carriers and Service Providers 5 91 92 Software Developers - ITU-T, TS (CCITT) - ANSI - ETSI - IETF... 93 94 95 96 97 Network Equipment Providers Semiconductor Vendors ATM Features ® Integration of LAN/MAN/WAN/MAN ® Supported By Standard And Industry Forums ® Supports Current And Future High-Bandwidth Applications And Protocols ® Independent of Physical Interface ® Interoperability With Conventional Technology ® Increased End-To-End BW ® Switch Based, Connection Oriented ® Small, Fixed Length Cell A ATM Benefits ® Simplified Networking And Architecture ® Better Multivendor Compatibility ® Long Architectural Lifetime ® Supports Current Cable Plant ® Migration Occurs At User’s Pace ® Dedicated And Deterministic Bandwidth ® One Network For All Traffic ® Supports New Applications Summary ATM combines a new set of networking features Connection oriented, based on switch technology and fixed length cell Uses existing cable plants Wide range of speed and distance Designed for LAN/MAN/WAN/MAN applications Evolution, not revolution, from existing networks and applications ATM is real and there is wide participation from all market segments B