University of burao

1. University of Burao
Department of ICT
Course: Data communication and Network
Presentation of ATM

2. Introduction of ATM
• ATM stands for Asynchronous Transfer
Mode, is high speed networking standard
designed to support both voice and data
communication.
• The cell used with ATM is relatively small
compared to units used with older
technologies.

3. User data
• The user data is divided into small, fixed-
length packets, called cells, and transported
over virtual connections.
• ATM uses short, fixed-length packets
called cells to carry data, and combines the
benefits of circuit switching with those of
packet switching.

4. ATM network interface card
• An ATM end system contains an ATM
network interface card.

5. ATM network
 An ATM network is made up of ATM switches and ATM end
systems (e.g. workstations, switches and routers).
 An ATM switch is responsible for cell transfer through an
ATM network. It accepts an incoming cell from an ATM end
system (or another ATM switch), reads and updates the cell
header information, and switches the cell to the appropriate
output interface.

6. ATM Reference Model

7. ATM Reference Model
 ATM functionality corresponds to the physical layer
and part of the data link layer of the OSI reference
model.
 The ATM reference model is composed of the
following planes, which span all layers:
 Control Plane: - This plane is responsible for
generating and managing signaling requests.
 User Plane: - This plane is responsible for managing
the transfer of data.

8. ATM Reference Model
 Management Plane:- This plane contains two
components: -
– Layer management: - manages layer-specific
functions, such as the detection of failures and
protocol problems.
– Plane management: - manages and coordinates
functions related to the complete system (End
System).

9. Physical layer
• The physical layer is subdivided into a
Physical Medium Dependent sub layer(PMD)
and Transmission Convergence sub
layer(TCS).
• The Physical Medium Dependent (PMD) sub
layer is responsible for the transmission and
reception of individual bits on a physical
medium.
• The TCS is create data format.

10. ATM cell formats
 ATM defines two different cell formats:
UNI (User-Network Interface) and
NNI (Network-Network Interface).
 Most ATM links use UNI cell format.

11. ATM Switches and Interfaces
ATM switch supports two types of interfaces:
– User-Network Interface (UNI)
• Connects an ATM end-point to a switch
– Network-Network Interface (NNI)
• Connects two ATM switches
Public and Private Interfaces
UNI and NNI can further be divided to two types
One is known as the private type and the other is
known as the public type

12. Private and Public UNI
 Private UNI
– Connects an ATM end-point to a private ATM
switch
 Public UNI
– Connects an ATM end-point or a private ATM
switch to a public ATM switch

13. Private and Public NNI
 Private NNI
– Connects two ATM switches within the same
private organization
 Public NNI
– Connects two ATM switches within the same
public organization

14. Conclusion
• ATM stands for isochronous transfer
mode
• ATM was originally designed in the mid
1980s for use in public networks, but has also
been organized as the backbone technology in
private networks.

15. Group name
• Group Names: -
• 1- Abdiaziz ibrahim jama
• 2- Abdiqani muuse ducaale
• 3- Kayse cabdi cali
• 4- Zekeriye xussien xasan
• 5- Osman muuse x.dirir
• 6- Abdihakim abdirazaq nour