1. 1 6/24/2015 01:59 CS575ATM Layers1 Rivier College CS575: Advanced LANs ATM Layers & Protocols

2. 2 6/24/2015 01:59 CS575ATM Layers2 ATM Layers and Sublayers Higher Layers ATM Adaptation Layer (AAL) Convergence Sublayer (CS) Segmentation and Reassembly Sublayer (SAR) ATM Layer (ATM) Virtual Channel (VC) Virtual Path (VP) Physical Layer (PL) Transmission Convergence Sublayer (TC) Physical Medium Sublayer (PM)

3. 3 6/24/2015 01:59 CS575ATM Layers3 ATM Information Transport Concept Higher Layer AAL ATM Layer Physical Layer End - to - End Edge - to - Edge Error Recovery & Flow Control Higher Layer AAL ATM Layer Physical Layer ATM Layer Physical Layer ATM Layer Physical Layer ATM Network User

4. 4 6/24/2015 01:59 CS575ATM Layers4 Functions of ATM Layers Cell rate decoupling HEC sequence generation/verification Cell delineation Transmission frame adaptation Transmission frame generation/recovery Generic flow control Cell Header generation/extraction Cell VPI/VCI translation Cell multiplexing Higher layers ATM Adaptation Layer Convergence Sublayer Segmentation and reassembly Sublayer ATM Layer Physical Layer Transmission convergence Sublayer Physical medium Sublayer High layer functions Convergence Segmentation and reassembly Bit timing Physical medium

5. 5 6/24/2015 01:59 CS575ATM Layers5 Physical Layer: Physical Medium (PM) Sublayer 0 Specify physical medium and transmission characteristics (e.g., multimode or single mode fiber) 0 Insertion and extraction of timing information 0 Specify bit timing, line coding Higher Layers ATM Adaptation Layer (AAL) Convergence Sublayer (CS) Segmentation and Reassembly Sublayer ( SAR ) ATM Layer (ATM) Virtual Channel (VC) Virtual Path (VP) Physical Layer (PL) Transmission Convergence Sublayer (TC) Physical Medium Sublayer (PM)

6. 6 6/24/2015 01:59 CS575ATM Layers6 Physical Layer Interfaces 0 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

7. 7 6/24/2015 01:59 CS575ATM Layers7 Physical Layer Interfaces (continued) 0 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

8. 8 6/24/2015 01:59 CS575ATM Layers8 Physical Layer Interfaces (concluded) 0 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)

9. 9 6/24/2015 01:59 CS575ATM Layers9 Transmission Convergence (TC) Sublayer 0 For transmission, receive cells from ATM layer 0 Pack/map cells into appropriate transport format -Cell-based -PLCP-based =DS-1 =DS-3 -SDH/SONET-based 0 Deliver cells to PM sublayer for transmission 0 Insert idle cells in order to provide a continuous flow of cells (cell rate decoupling) 0 HEC generation/verification 0 For receiving, extract cells from bit or byte stream received from PM sublayer

10. 10 6/24/2015 01:59 CS575ATM Layers10 Transmission Convergence (TC) Sublayer (concluded) 0 Cell delineation (detect cell boundaries) 0 Remove idle cells on receiving 0 Verify cell headers 0 Deliver valid cells to the ATM layer

11. 11 6/24/2015 01:59 CS575ATM Layers11 HEC Operation at Receiver Source: Stallings: Local and Metropolitan Networks p327

12. 12 6/24/2015 01:59 CS575ATM Layers12 Cell Delineation Source: Kyas: ATM Networks p155

13. 13 6/24/2015 01:59 CS575ATM Layers13 B-ISDN/ATM Protocol Reference Model Source: Stallings: Data and Computer Communications

14. 14 6/24/2015 01:59 CS575ATM Layers14 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.