HP 600 Series, Services And Applications

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AppleTalk Protocols
The AppleTalk protocols provide network-access standards for layers one
through five (in the Open Systems Interconnection (OSI) reference model).
Protocols for layers two through five are shown in figure 5.
AppleTalk Protocol Stack Corresponding OSI
Protocol Layer
Zone Information Protocol (ZIP) Session Layer (5)
Routing Table
Maintenance
Protocol
(RTMP) Name
Binding
Protocol
(NBP) AppleTalk
Echo Protocol
(AEP) Transport Layer (4)
Datagram Delivery Protocol (DDP) Network Layer (3)
AppleTalk Address Resolution Protocol (AARP) Data-Link Layer (2)
Figure 5. AppleTalk Protocols
AppleTalk Address Resolution Protocol (AARP)
Translates node addresses into equivalent station addresses.
Maintains the Address Mapping Table (AMT), which contains a
listing of equivalent node and station addresses.
Ensures the integrity of node addresses. When a node address is
assigned, AARP confirms the uniqueness of that address.
When a node identifier is dynamically determined, it must be automatically
validated as a unique node identifier on a given AppleTalk LAN. AARP
generates a random node identifier, or, if the node is being restarted and a
node identifier already exists in non-volatile memory, that node identifier
will be tested. To ensure that the node identifier is unique, AARP compares it
to entries in the Address Mapping Table. If no conflicts are found, then
AARP transmits a series of AARP Probe packets to the tentative address. If
there is no response, then AARP validates and uses the node identifier.
AARP Probe can be disabled if explicit addresses are going to be used.
However, it is recommended that dynamic addressing be used and that
AARP Probe remain at the default, enabled.
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AppleTalk Phase 2 Routing Service
AppleTalk Protocols
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