This document discusses switching to ATM technology. It outlines the benefits of ATM, including having a single network that can handle all traffic types with flexible bandwidth allocation. ATM networks have a simple structure with only stations and switches, point-to-point links, and can scale in size and capacity. The document also discusses how ATM can address networking needs through technologies like LAN Emulation and provides a staged strategy for migrating to ATM.

1. ATM in the Backbone and WAN
SS WW II TT CC HH II NN GG TT OO AA TT MM

2. 22
S W I T C H I N G T O A
T M
Agenda
• Basic ATM ConceptsBasic ATM Concepts
• Benefits of ATMBenefits of ATM
• Business Multimedia ApplicationsBusiness Multimedia Applications
• LAN Emulation (LANE)LAN Emulation (LANE)
• Strategies for ATM MigrationStrategies for ATM Migration

3. 33
S W I T C H I N G T O A
T M
The Potential of ATM
• ATM has the potentialATM has the potential
to displace all existingto displace all existing
internetworkinginternetworking
technologiestechnologies
• ATM has the potentialATM has the potential
to displace all otherto displace all other
LAN technologies inLAN technologies in
the backbonethe backbone
ATMATM

4. 44
S W I T C H I N G T O A
T M
The ATM Achievement
Network Simplicity
• One single network handles all traffic typesOne single network handles all traffic types
– Bursty dataBursty data
– Time-sensitive continuous trafficTime-sensitive continuous traffic
(voice/video)(voice/video)
• Bandwidth may be allocated flexibly to eachBandwidth may be allocated flexibly to each
• Single mechanism for both voice & dataSingle mechanism for both voice & data
A UNIVERSAL NETWORKING SOLUTIONA UNIVERSAL NETWORKING SOLUTION

5. 55
S W I T C H I N G T O A
T M
Structure of ATM Networks
• Only two kinds of devices: Stations and SwitchesOnly two kinds of devices: Stations and Switches
– No hubs, bridges, routersNo hubs, bridges, routers
• Stations connected by point-to-point linksStations connected by point-to-point links
– No sharing of bandwidth on the wireNo sharing of bandwidth on the wire
• Links can beLinks can be
different speedsdifferent speeds
• Links can beLinks can be
any lengthany length

6. 66
S W I T C H I N G T O A
T M
Implications of Structure
• ATM networks are architecturally simpleATM networks are architecturally simple
• ATM network size and capacity is scaleableATM network size and capacity is scaleable
• ATM can be applied in both LAN and WANATM can be applied in both LAN and WAN
A UNIVERSAL SOLUTIONA UNIVERSAL SOLUTION

7. 77
S W I T C H I N G T O A
T M
Competing Technologies
What problem are you trying to
solve?
• Networked MultimediaNetworked Multimedia
– Alternate: Switched LANsAlternate: Switched LANs
• High Speed to the DesktopHigh Speed to the Desktop
– Alternate: Fast Ethernet, 100VG-AnyLANAlternate: Fast Ethernet, 100VG-AnyLAN
• High Capacity BackboneHigh Capacity Backbone
– Alternate: FDDIAlternate: FDDI
• Voice/data integration in the WANVoice/data integration in the WAN
– Alternate: Smart TDMsAlternate: Smart TDMs

8. 88
S W I T C H I N G T O A
T M
Competing Technologies
ATM does it all
• 4 different problems, 1 solution : ATM4 different problems, 1 solution : ATM
• Competing technologies only address one orCompeting technologies only address one or
two of the problemstwo of the problems
• Greater mix of technologies = greaterGreater mix of technologies = greater
complexity = eventually higher costcomplexity = eventually higher cost
• All competing technologies are tacticalAll competing technologies are tactical
• ATM is strategic: promotes homogeneousATM is strategic: promotes homogeneous
networkingnetworking

9. 99
S W I T C H I N G T O A
T M
LAN Issues and LAN Technology
ATM providesATM provides ALLALL the answers:the answers:
Capacity -Capacity -
Dedicated links at 2, 25, 155, 622 MbpsDedicated links at 2, 25, 155, 622 Mbps
Capability -Capability -
Low latency, support for multiple trafficLow latency, support for multiple traffic
classesclasses
Flexibility -Flexibility -
Architectural Simplicity;Architectural Simplicity;
ATM Supported in both LAN and WANATM Supported in both LAN and WAN

10. 1010
S W I T C H I N G T O A
T M
Benefits of ATM Technology
• One network for all types of trafficOne network for all types of traffic
• Enables new applicationsEnables new applications
• Incremental migration capabilityIncremental migration capability
• Simplified network managementSimplified network management
• Long architectural lifetimeLong architectural lifetime

11. 1111
S W I T C H I N G T O A
T M
ATM Market Drivers
• Users have driven the PC and LAN revolutionUsers have driven the PC and LAN revolution
• Bandwidth needs keep on climbingBandwidth needs keep on climbing
• PCs increasingly support multimediaPCs increasingly support multimedia
– Power up by factor of 10 every 3 yearsPower up by factor of 10 every 3 years
– Next generation processors video-enabledNext generation processors video-enabled
– Video coding and compression in softwareVideo coding and compression in software
• ATM provides a universal, strategic solutionATM provides a universal, strategic solution
• A radically improved network infrastructureA radically improved network infrastructure
means new opportunities for business advantagemeans new opportunities for business advantage

12. 1212
S W I T C H I N G T O A
T M
LAN Emulation over ATM
Resolving the Differences
Packet SizePacket Size
Data TransferData Transfer
AddressingAddressing
Ethernet, TR LANsEthernet, TR LANs
Variable, < 4000 bytesVariable, < 4000 bytes
ConnectionlessConnectionless
Unique MAC AddressUnique MAC Address
ATMATM
Fixed, 48 bytesFixed, 48 bytes
Connection orientedConnection oriented
Virtual ChannelVirtual Channel
• How to run existing applications over ATM?How to run existing applications over ATM?
• How to connect existing LANs to ATM?How to connect existing LANs to ATM?

13. 1313
S W I T C H I N G T O A
T M
LAN Emulation Standard
• Defines emulation of Ethernet and Token RingDefines emulation of Ethernet and Token Ring
• Designed by Madge, Cisco, Fore, Bay NetworksDesigned by Madge, Cisco, Fore, Bay Networks
• Standard Version 1.0 ratified May 95Standard Version 1.0 ratified May 95
• LANE v2.0 due by 4Q96LANE v2.0 due by 4Q96
The ATM ForumThe ATM Forum

14. 1414
S W I T C H I N G T O A
T M
LAN Emulation for Integration
• LAN Emulation allows ATM to look likeLAN Emulation allows ATM to look like
Token Ring or EthernetToken Ring or Ethernet
• Can bridge, route or switch from real LAN toCan bridge, route or switch from real LAN to
emulated LANemulated LAN
• Switching provides most economical meansSwitching provides most economical means
to connect multiple LANs to ATMto connect multiple LANs to ATM

15. 1515
S W I T C H I N G T O A
T M
A Strategy for ATM integration
• Offer switching products for collapsed TokenOffer switching products for collapsed Token
Ring and Ethernet backbonesRing and Ethernet backbones
• Offer choice of FDDI and ATM for switchOffer choice of FDDI and ATM for switch
interconnectinterconnect
• Develop LAN Emulation over ATMDevelop LAN Emulation over ATM
• Provide complete workgroup solution for endProvide complete workgroup solution for end
to end ATMto end ATM

16. 1616
S W I T C H I N G T O A
T M
Switches for ATM Integration
• Switch interconnects LANsSwitch interconnects LANs
• Integrates LANs with ATMIntegrates LANs with ATM
backbonebackbone
HubHub
HubHub
HubHub
ATM SwitchATM Switch
ATMATM
LAN SwitchLAN Switch LAN SwitchLAN Switch LAN SwitchLAN Switch

17. 1717
S W I T C H I N G T O A
T M
Switches and LAN Emulation
HubHub LAN SwitchLAN Switch
ATM SwitchATM Switch ServerServer
LAN packet inLAN packet in
ATM Cells outATM Cells out
of TR Switchof TR Switch
ATM CellsATM Cells
into serverinto server
SegmentationSegmentation
Re-assemblyRe-assembly
AcrossAcross
networknetwork

18. 1818
S W I T C H I N G T O A
T M
ATM Migration
Integration Strategies
• Where is ATM needed most?Where is ATM needed most?
– Networked multimedia applicationsNetworked multimedia applications
– Workgroup ATM solutionsWorkgroup ATM solutions
– Overall LAN capacityOverall LAN capacity
– LAN switching and backbone ATM solutionsLAN switching and backbone ATM solutions
• Companies may need to attend to bothCompanies may need to attend to both
multimedia and backbone requirements atmultimedia and backbone requirements at
the same time or one or the otherthe same time or one or the other

19. 1919
S W I T C H I N G T O A
T M
Stage 1
Improve LAN Performance with
Switching
HubHub
LAN SwitchLAN Switch
HubHub

20. 2020
S W I T C H I N G T O A
T M
Stage 2
Interconnect LAN Switches with ATM
Backbone
155 Mbps155 Mbps
ATM SwitchATM Switch
HubHub
LAN SwitchLAN Switch
HubHub
LAN SwitchLAN Switch LAN SwitchLAN Switch

21. 2121
S W I T C H I N G T O A
T M
Stage 3
Connect Servers Direct to ATM
Backbone
HubHub
LAN SwitchLAN Switch
HubHub
ServersServers
155 Mbps155 Mbps
ATM SwitchATM Switch
LAN SwitchLAN Switch LAN SwitchLAN Switch

22. 2222
S W I T C H I N G T O A
T M
Stage 4
Move Power Users to ATM
Connections
HubHub
LAN SwitchLAN Switch
HubHub
ServersServers
PowerPower
UsersUsers
155 Mbps155 Mbps
ATM SwitchATM Switch
LAN SwitchLAN Switch LAN SwitchLAN Switch

23. 2323
S W I T C H I N G T O A
T M
Stage 5
Add ATM Workgroups
HubHub
SwitchSwitch
25 Mbps ATM25 Mbps ATM
SwitchSwitch
HubHub
ServersServers
PowerPower
UsersUsers
155 Mbps155 Mbps
ATM SwitchATM Switch
SwitchSwitch SwitchSwitch

24. 2424
S W I T C H I N G T O A
T M
ATM Integration Strategy
Local ATM BackboneLocal ATM Backbone
Move Servers to ATMMove Servers to ATM
Move Power Users to ATMMove Power Users to ATM
Replace retiring hubs with ATMReplace retiring hubs with ATM
19961996
19991999
ATM WorkgroupsATM WorkgroupsLAN SwitchingLAN Switching
Load DrivenLoad Driven Application DrivenApplication Driven

25. 2525
S W I T C H I N G T O A
T M
Summary
• Users will find compelling reasons forUsers will find compelling reasons for
multimediamultimedia
• Network planners growing wearyNetwork planners growing weary
– Patching up the network to increase capacityPatching up the network to increase capacity
– Dealing with multiple different technologiesDealing with multiple different technologies
• ATM is solution to 4 major networkingATM is solution to 4 major networking
problemsproblems
• ATM is strategic: promotes homogeneousATM is strategic: promotes homogeneous
networkingnetworking
19991999
1998199819971997
19961996

26. SS WW II TT CC HH II NN GG TT OO AA TT MM