Appletalk Transaction Protocol (Atp); Appletalk Echo Protocol (Aep); Name Binding Protocol (Nbp); Appletalk Data Stream Protocol (Adsp) - 3Com CoreBuilder 2500 User Manual

8-8 C 8: R
HAPTER OUTING WITH
Session Layer
Protocols
A T T
PPLE ALK ECHNOLOGY

AppleTalk Echo Protocol (AEP)

AppleTalk nodes use the AEP to send datagrams to other nodes in the
network. The AEP datagram transmitted causes the destination node to
return, or echo, the datagram to the sending node. This protocol
determines whether a node is accessible before any sessions are started,
and it enables users to estimate the round-trip delay time between nodes.

AppleTalk Transaction Protocol (ATP)

This protocol, along with the AppleTalk Data Stream Protocol (ADSP),
ensures delivery of DDP packets to a destination without any losses or
corruption.

Name Binding Protocol (NBP)

This protocol translates alphanumeric entity names to AppleTalk
addresses. NBP maintains a table of node addresses and named entities
within each node. Because each node also maintains its own list of
named entities, the names directory within an AppleTalk network is not
centralized. The names directory database is distributed among all nodes
on the intranet.
An AppleTalk intranet has four session-layer protocols:

AppleTalk Data Stream Protocol (ADSP)

Zone Information Protocol (ZIP)

AppleTalk Session Protocol (ASP)
Printer Access Protocol (PAP)
AppleTalk Data Stream Protocol (ADSP)
The ADSP works with the ATP to ensure reliable data transmission. Unlike
ATP, however, ADSP provides full-duplex byte-stream delivery. Therefore,
two nodes can communicate simultaneously. ASDP also includes flow
control, so that a fast sender does not overwhelm a slow receiver.
Zone Information Protocol (ZIP)
ZIP works with RTMP to map network numbers to network zones for the
entire AppleTalk intranet. Network zones are the logical groupings of
AppleTalk networks. The table created by ZIP is called the Zone
Information Table (ZIT). You view the ZIT by network number or network
zone from the Administration Console.