A. Cell
B. Atom
C. Molecule
D. Packet
Explanation: The data unit of ATM is cell. They are routed based on header information in each unit (called a label) that identifies the cell as belonging to a specific ATM virtual connection.
A. 48 bytes
B. 47 bytes
C. 5 bytes
D. 53 bytes
Explanation: ATM cells have a fixed length of 53 bytes. It consists of 48 bytes of data and 5 bytes of header information. Fixed length packets result in simple implementation of fast packet switches.