3com 2500 用户指南
8-4
C
HAPTER
8: R
OUTING
WITH
A
PPLE
T
ALK
T
ECHNOLOGY
Seed Routers
A seed router initializes the intranet with AppleTalk configuration
information, including network numbers and zone names. The seed
router broadcasts this information so that nonseed routers can learn it.
You designate a seed router through the Administration Console.
information, including network numbers and zone names. The seed
router broadcasts this information so that nonseed routers can learn it.
You designate a seed router through the Administration Console.
A nonseed router listens for a seed router and takes configuration
information from the first one it detects. A nonseed router that obtains
configuration data participates in the network as if it is a seed router.
information from the first one it detects. A nonseed router that obtains
configuration data participates in the network as if it is a seed router.
AppleTalk Protocols
AppleTalk protocols ensure the flow of information through AppleTalk
networks. Figure 8-2 shows a simplified view of AppleTalk protocols and
their relationship to the OSI Reference Model. These protocols provide
physical connectivity, end-to-end network services, and data delivery.
networks. Figure 8-2 shows a simplified view of AppleTalk protocols and
their relationship to the OSI Reference Model. These protocols provide
physical connectivity, end-to-end network services, and data delivery.
Figure 8-2 AppleTalk Protocols and the OSI Reference Model
The AppleTalk six-layer protocol suite does not fully comply with the OSI
seven-layer model. However, AppleTalk provides many of the functions
and services of OSI. AppleTalk has no specific protocols for the
Application layer because the lower levels provide printer and file service.
seven-layer model. However, AppleTalk provides many of the functions
and services of OSI. AppleTalk has no specific protocols for the
Application layer because the lower levels provide printer and file service.
Application
Presentation
Session
Transport
Network
Data link
Physical
OSI Reference Model
AppleTalk
Data Stream
Protocol (ADSP)
Routing Table
Maintenance
Protocol (RTMP)
PostScript
TokenTalk
Link Access
Protocol
EtherTalk
Link Access
Protocol
Token ring
hardware
Ethernet
hardware
LocalTalk
hardware
hardware
Datagram Delivery Protocol (DDP)
Name Binding
Protocol (NBP)
AppleTalk Echo
Protocol (AEP)
Protocol (AEP)
AppleTalk
Transaction
Protocol (ATP)
Printer Access
Protocol (PAP)
AppleTalk
Filing
Protocol (AFP)
AppleTalk
Session
Protocol (ASP)
LocalTalk
Link Access
Protocol
Zone
Information
Protocol (ZIP)