ATM is a packet-oriented transfer mode. It allows multiple logical connections to be multiplexed over a single physical interface. The information flow on each logical connection is organized into fixed-size packets, called cells. As with frame relay, there is no link-by-link error control or flow control.

1. ATM
No of slides:23
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2.  Overview
 Definition
 ATM cells
 Characteristics
 Protocol Architecture
 Pros & cons
 Applications
 Case study
 Research
 Bibliography
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3.  ATM is a packet-oriented transfer mode. It allows
multiple logical connections to be multiplexed
over a single physical interface. The information
flow on each logical connection is organized into
fixed-size packets, called cells. As with frame
relay, there is no link-by-link error control or
flow control.
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4. "A transfer mode in which information is organized
into cells; it is asynchronous in the sense that the
recurrence of cells containing information from an
individual user is not necessarily periodic".
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5. The ATM cell has 53 bytes, containing 5 bytes of header
and 48 bytes of information.
The advantages of this small and fixed cell size are:
 Cells can be switched more efficiently.
 Cell size is fixed.
 Queuing delay is reduced.
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6.  ATM uses packet switching with fixed length packet of
53 bytes – CELLs.
 ATM uses Virtual Circuits
 ATM can run over any physical layer.
 A Cell network uses the cell as the basic unit of data
exchange.
 ATM uses asynchronous TDM
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8. Physical layer:
 Involves the specification of transmission medium and
the signal encoding scheme.
 Data rate specified in this layer 155.52Mbps and
622.08Mbps.
ATM layer:
 Provide packet transfer capabilities.
 Defines transmission of data in fixed size cells.
 Define the use of the logical connection.
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9. ATM Adaptation Layer(AAL):
 Service dependent.
 Maps higher layer information into ATM cells to be
transported over an ATM network .
 Collects the information from ATM cells for deliver to
higher layers.
It consists of three separate planes:
1.User plane
2.Control plane
3.Management plane
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10. User plane:
provides user information transfer along with
associated controls.
Control plane:
performs call control and connection control
function.
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11. 1.Plane management
• it performs management functions related to a system.
• Provides coordination between all the planes.
2.Layer management
• It performs management functions relating to resources
and parameters residing in its protocol entities.
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13.  Two levels of ATM connections:
virtual path connections
virtual channel connections
 Indicated by two fields in the cell header:
virtual path identifier VPI
virtual channel identifier VCI
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14.  Setup between two end users. through the network.
 Leads to control signaling and user-network exchange,
network-network exchange.
Advantages:
1.Simplified network architecture
2.Increased network performance and reliability.
3.Reduced processing and short connection setup
4.Enhanced network services.
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15. A VCC can be established between end users, between
end user and switch, or between two switches.
 Between end users
 Between end user and switch
 Between two switches
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16.  Helps to contain the control cost by grouping
connections sharing common paths through the
network into a single unit.
 Network management actions can be applied to a small
number of groups of connections instead of a large
number of individual connection.
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17.  higher transmission speeds
 quality of service
 bandwidth-on-demand
 application-independent
 Cost
 Complexity
 Availability
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18. ATM is used for applications such as audio/video
transmission in real time
it is necessary that at the receiving end,
 the cells are received without variable delay.
 the cells should be received at a constant speed.
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19. MEDICAL:
 Medical imaging applications include storing and
manipulating x-rays, CAT scans, and MRI images
in digital form. Such images need to be accessed
simultaneously by multiple physicians.
Transporting them across a network to the
physicians requires a great deal of bandwidth,
which ATM technology can provide.
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20.  For several years now Milan's public transport
company’s policy has been to adopt a continuous
evolution of its processes towards paperless solutions.
 In 2005 the company decided to replace its old
document system since it had become obsolete, with
a platform satisfying requirements of scalability,
reliability and flexibility, thus allowing the
optimization of management and digital storage
procedures for the various types of documents
“transiting” the business, from invoices to internal
and external correspondence together with the
management of contraventions
 effected and legal documents of various kinds.
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21.  Multimedia will be one of the key applications to use ATM.
 In the near future ATM is intended to be used as a
backbone for other existing services like frame relay.
 improve LAN/Client-Server architectures and LAN
interconnection.
 ATM will provide the resources to ease the network
demands caused by the growing number of users that need
to connect to a LAN, and with applications requiring more
bandwidth.
 The IETF was working on IP over ATM and routing over large
clouds.
 ATM is currently the focus of the communications industry
ATM will likely be replaced by another technology such as
Wavelength Division Multiplexing (WDM).
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22.  http://www.ijsrp.org/research-paper-0413/ijsrp-
p16118.pdf
 https://www.youtube.com/watch?v=3VAmcN8VmIU
 https://en.wikipedia.org/wiki/Asynchronous_Transfer_Mod
e
 http://searchnetworking.techtarget.com/definition/ATM
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