The Ipx Protocol - Novell NETWARE 6-DOCUMENTATION Manual

Figure 1 How NetWare Protocols Correspond to the OSI Reference Model
Application
Applications
Presentation
Session
Transport
Network
Data Link
Physical

The IPX Protocol

12
Internetwork Packet Exchange
NetBIOS
SAP
NetBIOS
IPX
(Ethernet, token ring, ARCnet*)
The higher-level protocols (NetBIOS, SAP, NCP, SPX, NLSP, and RIP) rely
on the MAC protocols and IPX to handle lower-level communications, such
as node addressing. With the exception of NetBIOS, NCP, and SPX, each of
these protocols plays a role in the operation of IPX routing.
Novell adapted IPX from the Xerox* Network System (XNS*) Internet
Datagram Protocol (IDP). IPX is a connectionless datagram protocol.
Connectionless means that when a process running on a particular node uses
IPX to communicate with a process on another node, no connection between
the two nodes is established. Thus, IPX packets are addressed and sent to their
destinations, but there is no guarantee or verification of successful delivery.
Any packet acknowledgment or connection control is provided by protocols
above IPX, such as SPX. Datagram means that each packet is treated as an
individual entity, having no logical or sequential relation to any other packet.
As shown in Figure
layer protocol, IPX addresses and routes packets from one location to another
on an IPX internetwork. IPX bases its routing decisions on the address fields
in its header and on the information it receives from RIP or NLSP. IPX uses
this information to forward packets to their destination node or to the next
router providing a path to the destination node.
NetWare
Applications
NCP
SPX
NLSP
MAC Protocols
1, IPX operates at the OSI Network layer. As a Network-
RIP