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Rivier College CS575: Advanced LANs ATM Layers & Protocols. Higher Layers. Convergence Sublayer (CS). ATM Adaptation Layer (AAL). Segmentation and Reassembly Sublayer (SAR). Virtual Channel (VC) Virtual Path (VP). ATM Layer (ATM). Transmission Convergence Sublayer (TC).
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Rivier CollegeCS575: Advanced LANsATM Layers & Protocols ATM Layers
Higher Layers Convergence Sublayer (CS) ATM Adaptation Layer (AAL) Segmentation and Reassembly Sublayer (SAR) Virtual Channel (VC) Virtual Path (VP) ATM Layer (ATM) Transmission Convergence Sublayer (TC) Physical Layer (PL) Physical Medium Sublayer (PM) ATM Layers and Sublayers ATM Layers
ATM Network User User Error Recovery & Flow Control Higher Higher End - to - End Layer Layer AAL Edge - to - Edge AAL ATM ATM ATM ATM Layer Layer Layer Layer Physical Physical Physical Physical Layer Layer Layer Layer ATM Information Transport Concept ATM Layers
Functions of ATM Layers Higher layers High layer functions Convergence Convergence ATM Sublayer Adaptation Segmentation Layer and reassembly Segmentation and reassembly Sublayer Generic flow control Cell Header generation/extraction ATM Layer Cell VPI/VCI translation Cell multiplexing Cell rate decoupling HEC sequence generation/verification Transmission Cell delineation convergence Physical Transmission frame adaptation Sublayer Transmission frame generation/recovery Layer Physical medium Bit timing Sublayer Physical medium ATM Layers
Higher Layers Convergence Sublayer (CS) ATM Adaptation Layer (AAL) Segmentation and Reassembly Sublayer (SAR) Virtual Channel (VC) Virtual Path (VP) ATM Layer (ATM) Transmission Convergence Sublayer (TC) Physical Layer (PL) Physical Medium Sublayer (PM) Physical Layer:Physical Medium (PM) Sublayer • Specify physical medium and transmission characteristics (e.g., multimode or single mode fiber) • Insertion and extraction of timing information • Specify bit timing, line coding ATM Layers
Physical Layer Interfaces • Three major categories of physical layer interfaces for ATM networks: • The existing Plesiochronous Digital Hierarchy (PDH): (Designed for used over copper media) • DS-1 (1.544 Mbps) • DS-3 (44.736 Mbps) • E1 (2.048 Mbps) • E3 (34.368 Mbps) • E4 (139.264 Mbps) • The new Synchronous Digital Hierarchy (SDH): (Designed for used over fiber optic links) • STS-3 (155.52 Mbps) • STS-12 (622.080 Mbps) • Physical media used on the local premises for ATM LANs ATM Layers
Physical Layer Interfaces (continued) • Interfaces specified by the ATM Forum UNI Specification V3.1: • SONET STS-3c (OC-3c) Interface • Based on SDH/SONET standards • For public and private UNI • 155.52 Mbps • Single mode and multimode fiber • DS-3 Interface • Based on ANSI T1E1.2/94-002R1 standard • For public and private UNI • 44.736 Mbps • Physical Layer Convergence Protocol (PLCP) defined to carry DS-3 ATM cells (excluding PLCP overhead, 40.704 Mbps available for ATM cells) • Coaxial cable media ATM Layers
Physical Layer Interfaces (concluded) • Other interfaces: • 155 Mbps STS-3 over UTP-5 • 34.368 Mbps (E-3) • 139.264 Mbps (E-4) • 1.544 Mbps (T-1) • 2.048 Mbps (E-1) ATM Layers
Transmission Convergence (TC) Sublayer • For transmission, receive cells from ATM layer • Pack/map cells into appropriate transport format • Cell-based • PLCP-based • DS-1 • DS-3 • SDH/SONET-based • Deliver cells to PM sublayer for transmission • Insert idle cells in order to provide a continuous flow of cells (cell rate decoupling) • HEC generation/verification • For receiving, extract cells from bit or byte stream received from PM sublayer ATM Layers
Transmission Convergence (TC) Sublayer (concluded) • Cell delineation (detect cell boundaries) • Remove idle cells on receiving • Verify cell headers • Deliver valid cells to the ATM layer ATM Layers
HEC Operation at Receiver Source: Stallings: Local and Metropolitan Networks p327 ATM Layers
Cell Delineation Source: Kyas: ATM Networks p155 ATM Layers
B-ISDN/ATM Protocol Reference Model Source: Stallings: Data and Computer Communications ATM Layers
W. Stalling, Local and Metropolitan Area Networks, 6th edition, Prentice Hall, 2000, Chapter 11 References W. Stalling, Data and Computer Communications, 6th edition, Prentice Hall, 2002, Chapters 11-12 A. Wu, Advanced Local Area Networks, Lectures & Slides, Rivier College, 2001. ATM Layers