1. Asynchronous Transfer Mode
Instructor
Mr. Roy Jolly. By
Devender Kasturi

2. University of North Texas
Overview
Introduction
Why ATM?
ATM Implementation example.
Business & Profits
ATM Switch
Conclusions
Questions and Suggestions
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University of North Texas

3. University of North Texas
Introduction
ATM – Asynchronous Transfer Mode
Past Situation
Emerged in 1990s but could not take off immediately because of cost of implementation
High cost mainly due to lack of technology to make fast ATM switches
Inability of organizations to use high bandwidth provided by ATM
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University of North Texas

4. University of North Texas
Introduction
Present situation
Emergence of VLSI Technology to make fast transistor switching possible.
Increase in demand for fast networks.
Lowering of prices for ATM switches and Interface cards.
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University of North Texas

5. University of North Texas
What is ATM?
A packet switching network.
Connection oriented network.
Simple concept
Data is broken down into cells
ATM frame consists of 53 such cells
5 cells are used as header
Remaining 48 cells are the payload
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University of North Texas

6. What is ATM? contd… ATM Frame 5 bytes of header Flow Control
Virtual Path Identifier
Virtual Circuit Identifier
Payload Type
Header Error Control (HEC)
Cell
Loss priority
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
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University of North Texas

7. University of North Texas
ATM AAL’s
Traffic Class
Class A
Class B
Class C
Class D
Adaptation Layer
AAL-1
AAL-2
AAL-3/4
AAL-5 (SEAL)
Mode
Connection Oriented
Connectionless
End-to-End Timing?
Yes No
Bit Rate
Constant
Variable
Examples
PCM voice, constant bit-rate video
Variable bit-rate voice and video
Frame relay, SNA, TCP-IP,
SMDS
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Physical Layers
Largely ‘physical layer’ independent
E1, E3, DS3, OC3, OC12, etc
Megabits rather than kilobits
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University of North Texas

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Why ATM?
Incorporates variety of information
Voice, video, data, multimedia
Applications in the field of:
Business
Manufacturing
Health Care
Government
Software
Legal
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University of North Texas

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Why ATM?
Lowers network costs because of a common network.
Higher Bandwidth
Flexible Bandwidth
QOS
Standardization of equipment
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University of North Texas

11. Implementation Example
Sprint ATM Network
Consists of ATM network with a range of ATM switches and an Integrated Services HUB.
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12. University of North Texas
DCS Defense Communication System
POP point of presense
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University of North Texas

13. ATM Network ISH Sprint ATM Network Structure 11/11/2018
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14. Integrated Services Hub
Aggregates networks and provide multi service access concentration.
Examples
Cisco 1720
Cisco NxT1
Cisco NxT1
Cisco 3810
Nortel Passport 6420
Nortel Passport 6440
Nortel Passport 6480
The Integrated Services Hub is the data equipment that aggregate the networks and provide multi service access concentration for frame relay or ATM services. Sprint tailors network consolidation to meet the needs of the business applications. The integrated services hubs we use to provide Sprint Network Consolidation are:
Cisco One port and two slots for small branch offices
Cisco NxT1, one to three ports for small to medium businesses
Cisco NxT1, multiple (more than three) ports for medium businesses
Cisco One T1 port for small branch offices
Nortel Passport three slots for small branch offices
Nortel Passport five slots for medium size locations
Nortel Passport slots for large corporate locations
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Integrated
Services
Hub (ISH)
LAN
Dedicated IP
Video
PBX systems
Managed Network Service
Fax
Voice
Workstation
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16. Another Example… ATM Backbone Network of British Airways 11/11/2018
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ATM Growth
Results for backbone technologies adopted obtained from studies by Infonetics Research.
IP and ATM are prevalent networks
MPLS Growing Fast
Suggests Multi-service networks.
Infonetics Research is an international market research and consulting firm covering the data networking and telecommunications industries in North America, Europe, and Asia. We provide objective analysis of end-users, service providers, and product manufacturers through in-depth research studies, quarterly market share and forecast services, and consulting and custom research services.
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University of North Texas

18. University of North Texas
ATM QOS
Results obtained from Infonetics Research.
ATM dominant.
MPLS growing fast.
MPL :- Multiprotocol Label Switching
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University of North Texas

19. University of North Texas
Sprint Business
Sprint ATM service has been voted #1 in QOS.
Many organizations small or large are adopting this service.
Because of this a lot of profits are being reaped by Sprint.
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University of North Texas

20. Cisco BPX 8600 Series Switches
Standards-based ATM switch with advanced IP and ATM capabilities.
Designed to meet the demanding, high-traffic needs
Delivers high-performance ATM switching, multi-service adaptation and aggregation
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21. Cisco BPX 8600 Series Switches
Up to 20 Gbps of high-throughput switching
Supports a wide range of interfaces, from Frame Relay to full broadband subscriber interfaces
Also supports multi-protocol label switching (MPLS)
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22. Cisco BPX 8600 Series Switches
Multi-shelf architecture
Allows users to incrementally expand the capacity of the system as needed and fully utilize the switch fabric
Advanced switching capabilities
Intelligent call processing for Frame Relay and ATM switched virtual circuits (SVCs)
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23. Cisco BPX 8600 Series Switches
Reliability
Automatic Routing Management reroutes virtual circuits if a trunk fails
Scalability
High service availability and performance
Robust, redundant architecture
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Conclusions
ATM network supports constant bit rate and variable bit rate applications.
Organizations are able to run different applications using a common network.
Lower cost of implementation because of a single network.
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University of North Texas

25. University of North Texas
Conclusions
ATM provides good QOS.
Organizations using ATM networks are earning profits.
ATM is a network for the future.
Compatible for implementing MPLS.
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University of North Texas

26. University of North Texas
References
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