The original networking protocol for Apple Macintosh networks. AppleTalk enables users to share folders and printers for access by other network users. AppleTalk is a legacy technology that has been largely replaced by Apple Open Transport, which supports AppleTalk, TCP/IP, and other popular network protocols.
AppleTalk is a workgroup-level networking technology that supports up to 254 network nodes per physical network. AppleTalk can run on top of the legacy LocalTalk data-link protocol, which was built into the Macintosh RS-449/RS-422 serial interface.
In the more recent AppleTalk Phase II, the data-link protocols supported include EtherTalk, TokenTalk, and FDDITalk for connectivity with Ethernet, Token Ring, and Fiber Distributed Data Interface (FDDI) networks, respectively.
Addresses of machines on AppleTalk networks are randomly self-assigned when the machine is first attached to the network, and then broadcast to ensure they are not already being used. This dynamic addressing feature is based on the AppleTalk Address Resolution Protocol (AARP). AppleTalk internetworks are logically partitioned into zones whose main function is to make network resources easier for users to access.
A zone is a logical representation of AppleTalk network nodes that can span multiple physical networks. The mapping between zones and network numbers is maintained by the Zone Information Protocol (ZIP), which creates Zone Information Tables (ZITs) that are stored on AppleTalk routers.
AppleTalk is a suite of networking protocols that work together to provide file and print sharing services to Macintosh networks. The following illustration shows the details of the AppleTalk protocol suite.
Apple Open Transport includes an updated version of AppleTalk with additional features such as support for manually assigned node addresses, support for multihomed and multinode systems, and other features.