1. 1 7/12/2015 15:20 Chapter 11ATM LANs1 Rivier College CS575: Advanced LANs Chapter 11: ATM LANs

2. 2 7/12/2015 15:20 Chapter 11ATM LANs2 Overview 0 ATM LAN Architecture 0 ATM LAN Emulation * Protocol Architecture * Emulated LANs * LAN Emulation Clients and Servers * LAN Emulation Scenario and Frame Formats 0 Asynchronous Transfer Mode * ATM Protocol Architecture * ATM Logical Connections * ATM Cells 0 ATM Adaptation Layer * ATM Service Categories * AAL Services and Protocols

3. 3 7/12/2015 15:20 Chapter 11ATM LANs3 Three Generations of LANs 0 First generation: Based on the CSMA/CD and Token Ring LANs. It provided terminal-to-host connectivity and supported client/server architectures at moderate data rates. 0 Second generation: Based on FDDI. It responds to the need for backbone LANs and for support of high-performance workstations. 0 Third generation: Typified by ATM LANs. It designed to provide the aggregate throughputs and real-time transport guarantees that are needed for multimedia applications.

4. 4 7/12/2015 15:20 Chapter 11ATM LANs4 Types of ATM LANs 0 Gateway to ATM WAN: An ATM switch acts as a router and traffic concentrator for linking a premises network complex to an ATM WAN. 0 Backbone ATM switch: Either a single ATM switch or a local network of ATM switches interconnect other LANs. 0 Workgroup ATM: High-performance multimedia workstations and other end systems connect directly to an ATM switch.

5. 5 7/12/2015 15:20 Chapter 11ATM LANs5 Example of a Backbone ATM LAN

6. 6 7/12/2015 15:20 Chapter 11ATM LANs6 ATM LAN Hub Configuration

7. 7 7/12/2015 15:20 Chapter 11ATM LANs7 ATM LAN Emulation 0 The issue of interoperability of end systems on a variety of interconnected LANs. 0 End systems attached directly to an ATM network implement the ATM and AAL protocols. 0 Three areas of compatibility: 1. Interaction between an end system on an ATM network and end system on a legacy LAN. 2. Interaction between an end system on a legacy LAN and end system on another legacy LAN of the same type (e.g., two IEEE 802.3 networks). 3. Interaction between an end system on a legacy LAN and end system on another legacy LAN of a different type (e.g., an IEEE 802.3 network and an IEEE 802.5 network).

8. 8 7/12/2015 15:20 Chapter 11ATM LANs8 Example: ATM LAN Emulation Configuration

9. 9 7/12/2015 15:20 Chapter 11ATM LANs9 ATM LAN Emulation Architecture

10. 10 7/12/2015 15:20 Chapter 11ATM LANs10 Emulated LANs 0 Possibility for a number of logically independent emulated LANs 0 An emulated LAN supports a single MAC protocol, of which two types are currently defined: Ethernet/IEEE 802.3 and Token Ring/IEEE 802.5 0 An emulated LAN consists of some combination of the following: * End systems on one or more legacy LANs * End systems attached directly to an ATM switch An emulated 0 Each end system on an emulated LAN must have a unique MAC address. Data interchange between end systems on the same emulated LAN involves the use of the MAC protocol and is transparent to the upper layers. 0 It appears to LLC that all of the end systems on an emulated LAN are on the same shared-medium LAN. 0 Communication between end systems on different emulated LANs is possible only through routers and bridges. 0 The bridges or routers have to reassemble the cells into packets and chop them up into cells to send them to another emulated LAN.

11. 11 7/12/2015 15:20 Chapter 11ATM LANs11 LAN Emulation Clients and Servers 0 ATM Forum developed a capacity based on a client/server approach to resolve the following issues: 1. Devices attached directly to ATM switches and ATM-to-LAN converter systems have ATM-based addresses. HOW are the translations made between these addresses and MAC addresses? 2. ATM makes use of a connection-oriented protocol involving virtual channels and virtual paths. HOW can the connectionless LAN MAC protocol be supported over this connection-oriented framework? 3. Multicasting and Broadcasting on a shared-medium LAN is easily achieved. HOW is this capability carried over into the ATM environment?

12. 12 7/12/2015 15:20 Chapter 11ATM LANs12 LAN Emulation Clients and Servers (continued)

13. 13 7/12/2015 15:20 Chapter 11ATM LANs13 LAN Emulation Client Connection across LAN Emulation User-to-Network Interface (LUNI)

14. 14 7/12/2015 15:20 Chapter 11ATM LANs14 LAN Emulation Data Frame Format: IEEE 802.3

15. 15 7/12/2015 15:20 Chapter 11ATM LANs15 LAN Emulation Data Frame Format: IEEE 802.5

16. 16 7/12/2015 15:20 Chapter 11ATM LANs16 LAN Emulation Data Frame Format

17. 17 7/12/2015 15:20 Chapter 11ATM LANs17 Asynchronous Transfer Mode Overview: ATM Protocol Architecture

18. 18 7/12/2015 15:20 Chapter 11ATM LANs18 ATM Connection Relationships

19. 19 7/12/2015 15:20 Chapter 11ATM LANs19 Call Establishment Using Virtual Paths

20. 20 7/12/2015 15:20 Chapter 11ATM LANs20 Virtual Path/Virtual Channel Terminology * Error-detection technique requires an Error-Detecting Code (e.g., CRC)

21. 21 7/12/2015 15:20 Chapter 11ATM LANs21 ATM Cell Formats * Error-detection technique requires an Error-Detecting Code (e.g., CRC)

22. 22 7/12/2015 15:20 Chapter 11ATM LANs22 Payload Type (PT) Field Coding

23. 23 7/12/2015 15:20 Chapter 11ATM LANs23 Header Error Control (HEC) Operation at Receiver

24. 24 7/12/2015 15:20 Chapter 11ATM LANs24 Effect of Error in Cell Header

25. 25 7/12/2015 15:20 Chapter 11ATM LANs25 Impact of Random Bit Errors on HEC Performance

26. 26 7/12/2015 15:20 Chapter 11ATM LANs26 ATM Adaptation Layer (AAL)

27. 27 7/12/2015 15:20 Chapter 11ATM LANs27 AAL Protocols and Protocol Data Units (PDUs)

28. 28 7/12/2015 15:20 Chapter 11ATM LANs28 Segmentation & Reassembly (SAR) Protocol Data Units (PDUs)

29. 29 7/12/2015 15:20 Chapter 11ATM LANs29 AAL Type 5 CPCS-PDU (Common Part Convergence Sublayer)

30. 30 7/12/2015 15:20 Chapter 11ATM LANs30 Example of AAL 5 Transmission