AppleTalk is the original networking protocol for Apple Macintosh networks. AppleTalk enables users to share folders and printers for access by other network users.
What is AppleTalk?
AppleTalk is a proprietary suite of networking protocols developed by Apple Inc. for their Macintosh computers. AppleTalk included a number of features that allowed local area networks to be connected with no prior setup or the need for a centralized router or server of any sort. Connected AppleTalk-equipped systems automatically assigned addresses, updated the distributed namespace, and configured any required inter-networking routing. It was a plug-n-play system.
AppleTalk was first released in 1985 and was the primary protocol used by Apple devices through the 1980s and 90s. Versions were also released for the IBM PC and compatibles, and the Apple IIGS. AppleTalk support was also available in most networked printers, some file servers and a number of routers.
How AppleTalk Work?
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 by layer (OSI Model)
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 and its relationship with the seven-layers OSI model.
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.