What is the unit of data transferred by an ATM network?

The unit of data transferred by an ATM (Asynchronous Transfer Mode) network is referred to as a cell. ATM networks are designed for the efficient and fast transfer of data, especially for real-time applications like voice and video. Each cell has a fixed size of 53 bytes, which consists of a 5-byte header and a 48-byte payload. This fixed size is crucial for maintaining the high-speed, low-latency transmissions that ATM is known for, enabling the network to handle various types of traffic seamlessly.

Understanding the role of cells in ATM networks is essential because they enable the network to maintain Quality of Service (QoS) for different types of data, ensuring that time-sensitive information is transmitted promptly and reliably. This is fundamentally different from other types of data transfer units used in different networking technologies, such as frames in Ethernet or packets in IP networking, which can vary in size and structure.