Asynchronous Transfer Mode (ATM) in Computer Network
• Asynchronous Transfer Mode (ATM) is a high-speed networking technology that transmits
data using fixed-size cells of 53 bytes (5-byte header and 48-byte payload).
• ATM was designed to carry voice, video, and data efficiently over the same network while
providing Quality of Service (QoS). The ATM protocol architecture consists of three main
layers
• Asynchronous Transfer Mode (ATM) is a connection-oriented network
technology where sender devices, known as end-points, connect through
a User-to-Network Interface (UNI) to network switches. These switches
communicate with each other through Network-to-Network Interfaces
(NNI).
• ATM uses a hierarchical approach to organize traffic flow through virtual
paths and virtual channels, providing efficient bandwidth utilization and
Quality of Service (QoS) guarantees for different types of data transmission.
, ATM Layers:
1. ATM Adaption Layer (AAL) -
It is meant for isolating higher-layer protocols from details of ATM processes and prepares for conversion
of user data into cells and segments it into 48-byte cell payloads. AAL protocol excepts transmission from
upper-layer services and helps them in mapping applications, e.g., voice, data to ATM cells.
2. Physical Layer -
It manages the medium-dependent transmission and is divided into two parts physical medium-
dependent sublayer and transmission convergence sublayer. The main functions are as follows:
1. It converts cells into a bitstream.
2. It controls the transmission and receipt of bits in the physical medium.
3. It can track the ATM cell boundaries.
4. Look for the packaging of cells into the appropriate type of frames.
3. ATM Layer -
It handles transmission, switching, congestion control, cell header processing, sequential delivery, etc., and
is responsible for simultaneously sharing the virtual circuits over the physical link known as cell
multiplexing and passing cells through an ATM network known as cell relay making use of the VPI and VCI
information in the cell header.
• Asynchronous Transfer Mode (ATM) is a high-speed networking technology that transmits
data using fixed-size cells of 53 bytes (5-byte header and 48-byte payload).
• ATM was designed to carry voice, video, and data efficiently over the same network while
providing Quality of Service (QoS). The ATM protocol architecture consists of three main
layers
• Asynchronous Transfer Mode (ATM) is a connection-oriented network
technology where sender devices, known as end-points, connect through
a User-to-Network Interface (UNI) to network switches. These switches
communicate with each other through Network-to-Network Interfaces
(NNI).
• ATM uses a hierarchical approach to organize traffic flow through virtual
paths and virtual channels, providing efficient bandwidth utilization and
Quality of Service (QoS) guarantees for different types of data transmission.
, ATM Layers:
1. ATM Adaption Layer (AAL) -
It is meant for isolating higher-layer protocols from details of ATM processes and prepares for conversion
of user data into cells and segments it into 48-byte cell payloads. AAL protocol excepts transmission from
upper-layer services and helps them in mapping applications, e.g., voice, data to ATM cells.
2. Physical Layer -
It manages the medium-dependent transmission and is divided into two parts physical medium-
dependent sublayer and transmission convergence sublayer. The main functions are as follows:
1. It converts cells into a bitstream.
2. It controls the transmission and receipt of bits in the physical medium.
3. It can track the ATM cell boundaries.
4. Look for the packaging of cells into the appropriate type of frames.
3. ATM Layer -
It handles transmission, switching, congestion control, cell header processing, sequential delivery, etc., and
is responsible for simultaneously sharing the virtual circuits over the physical link known as cell
multiplexing and passing cells through an ATM network known as cell relay making use of the VPI and VCI
information in the cell header.
