CCNA Cisco Certified Network Associate Study Guide - FTP Server

Novell IPX Protocol Stack
Introduction to Novell IPX 387
IPX doesn’t map directly to the OSI model, but its protocols do function in
layers. Back when they designed IPX, engineers were more concerned with
performance than they were with strict compliance to existing standards or
models. Even so, comparisons can be made.
Figure 8.1 illustrates the IPX protocols, layers, and functions relative to
those of the OSI model.
FIGURE 8.1 IPX protocol stack and the OSI model
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6
5
4
3
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OSI Reference Model
Application
Presentation
Session
Transport
Network
Data Link
Physical
RIP
NLSP
Novell NetWare Protocols
SAP
NETBIOS
Applications
IPX IPX performs functions at layers 3 and 4 of the OSI model. It controls
the assignment of IPX addresses (software addressing) on individual
nodes, governs packet delivery across internetworks, and makes routing
decisions based on information provided by the routing protocols, RIP or
NLSP. IPX is a connectionless protocol (similar to TCP/IP’s UDP), so it
doesn’t require any acknowledgment that packets were received from the
destination node. To communicate with the upper-layer protocols, IPX
uses sockets. These are similar to TCP/IP ports in that they’re used to
address multiple, independent applications running on the same machine.
NCP
IPX
(Internetwork Packet Exchange)
Media Access Protocols
(Ethernet, Token Ring, WAN, others)
SPX