What does Appletalk Transaction Protocol provide?

Appletalk Transaction Protocol (ATP) is designed to operate at the transport layer of the networking model. It facilitates the management of requests and delivery of responses between applications, ensuring reliable communication over a network.

By specifically functioning at this level, ATP provides services that include establishing connections, maintaining the state of those connections during a session, and ensuring the correct delivery of data packets between devices. This transport layer role is crucial for achieving efficient communication in Appletalk networks, as it allows multiple applications to communicate without interference, handling anything from ensuring message order to retransmitting lost messages as necessary.

The transport layer also works closely with the session layer, which is responsible for managing sessions of communication between applications, but it is the transport layer that ensures reliable and ordered delivery of these messages. This is why ATP's function is categorized as a transport layer rather than an application layer, session layer, or physical layer.