The average ATM cell size is 53 bytes. This includes the 5-byte header, 48-byte data payload, and the CRC.
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ATM Cell Header
The ATM cell header is 5 bytes long and consists of the following fields:
-1 byte for the Generic Flow Control (GFC) field
-1 byte for the Virtual Path Identifier (VPI) field
-2 bytes for the Virtual Channel Identifier (VCI) field
-1 byte for the Payload Type Identifier (PTI) field
ATM Cell Size
ATM cells have a fixed size of 53 bytes. 48 of those bytes are used for the data payload, while the other 5 bytes are used for the header. The header includes information such as the type of data that is being carried in the cell, and the error-checking information.
ATM Cell Body
An ATM cell is composed of two parts, the cell header and the cell body. The cell header is 5 bytes long and contains information about the virtual circuit that the cell is a part of, as well as other control information. The cell body is 48 bytes long and contains the actual user data.
ATM Cell Payload
A standard ATM cell is 53 bytes in size, including the 5-byte header. The remaining 48 bytes are available for the data payload. So, what is the size of an ATM cell payload?
ATM Cell Trailer
The ATM cell trailer is 4 bytes long and includes the following information:
– CRC: A cyclic redundancy check is used to detect errors in the cell.
– GFC: The Generic Flow Control field is used for congestion control and consists of 4 bits.
– VPI: The Virtual Path Identifier is used to identify the Virtual Path that the cell belongs to. It consists of 8 bits.
– VCI: The Virtual Channel Identifier is used to identify the Virtual Channel that the cell belongs to. It consists of 16 bits.