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Suite of Protocols 259
Foundation Topics
If your customer is running Macintosh computers on the network and wants to install a protocol
that is user-friendly and simple to configure and maintain on a small LAN, you should consider
AppleTalk. If you need a protocol that scales to a large size, uses a minimum of bandwidth, and
interoperates well with other protocols, well, you should not consider AppleTalk.
Suite of Protocols
AppleTalk is a suite of protocols that were developed by Apple Computer to work on local-area
networks with Macintosh computers. Two versions of AppleTalk exist: AppleTalk Phase I and
AppleTalk Phase 2. Most users have migrated to AppleTalk Phase 2.
The AppleTalk suite of protocols supports a full range of applications. This chapter discusses
AppleTalk routing protocols later in greater detail.
The suite of protocols includes the following:
·
AppleTalk Address Resolution Protocol (AARP)--Operates at the network layer and
associates network addresses with hardware addresses. AARP is similar to ARP in IP.
·
Datagram Delivery Protocol (DDP)--Operates at the network layer and provides a best-
effort connectionless datagram service between AppleTalk sockets.
·
Name Binding Protocol (NBP)--Operates at the transport layer and maps the addresses
used at lower layers to AppleTalk names. The functionality of NBP is similar to the
Domain Name Service (DNS) in TCP/IP.
·
Zone Information Protocol (ZIP)--Maintains network number-to-zone name mappings
in AppleTalk routes. A zone is a logical grouping of AppleTalk resources.
·
Routing Table Maintenance Protocol (RTMP)--Responsible for establishing and
maintaining routing tables for AppleTalk routers. RTMP is a distance-vector protocol and
is quite similar to RIP in functionality.
·
AppleTalk Update-Based Routing Protocol (AURP)--Allows two or more AppleTalk
internetworks to be interconnected through a TCP/IP network to form a WAN. AURP
encapsulates packets in UDP headers, allowing them to flow transparently through a
TCP/IP network. AURP is designed to handle routing update traffic over WAN links more
efficiently than RTMP. AURP does not replace RTMP in the LAN environment.
·
AppleTalk DataStream Protocol (ADSP)--A session layer protocol that establishes and
maintains full duplex communication between two AppleTalk sockets.
·
AppleTalk Transaction Protocol (ATP)--A transport layer protocol that handles
transactions between two AppleTalk sockets.
87200333.book Page 259 Wednesday, August 22, 2001 2:37 PM