Novell NetWare X.x
Lots of companies created proprietary network protocols based on the XNS (Xerox Networking System) The foundation for almost all PC network protocol suites came from the XNS protocols. The layers and protocols in operation in XNS are almost identical to IPX / SPX .

Novell's implementation is called NetWare. The set of protocols that govern its operation are called IPX / SPX. These are two of the central protocols of this suite, but taken together IPX / SPX they make up the Novell stack.

The IPX/SPX protocols operating in NetWare provide the same services of any network protocols. Different tasks are isolated on different levels in file stack, and protocols handle the transfer of information between the layers of the stack and across the physical medium.

OSI	Novell Architecture
Application	NCP
Presentation	NCP
Session	NetBIOS (optional)
Transport	SPX
Network	IPX, SAP, RIP
Data Link	ODI driver - link support layer & media layer Access protocols - (Ethernet, etc)
Physical	Wiring

Physical Layer

The physical layer is defined by the type of network interface card and the physical medium (type of wire or cable) used to physically connect the machines operating on a network. Network interface cards are usually designed to operate with one particular access method.

Data Link Layer

In its proprietary architecture, Novell combines the physical and data link layers. Open data-link interface (ODI) is implemented as a software driver at this layer and handles the communication between the physical medium and the higher level protocols in the stack. Following a common

Network Layer

At this layer Novell provides the Internet packet exchange protocol. IPX provides addressing data for network transmissions and provides the delivery system for this data. IPX is a connections datagram protocol like IP in the TCP/IP suite. Like IP, IPX is concerned with the addressing and routing of packets. Although it makes its "best effort" to deliver a packet, IP is not concerned about the connection between hosts, only about the addressing and the delivery of the packets.

Transport Layer

For the transport layer Novell provides sequenced packet exchange. SPX provides the virtual connections-less between hosts that are necessary for applications to share processing information. Since NetWare is designed for high-quality transmission at the data link layer and since NCP takes care of some error control and sequencing on the server and the client, SPX is rarefy used.

Session Layer

NetWare supports the NetBIOS interface, which provides a link between external network applications and the operating system. Novell's own approach to NetWare communications does not use NetBIOS, however; it is supported primarily for the benefit of applications seeking to take advantage of this service.

Presentation and Applications Layers

Novell's network architecture, like that of XNS, does not distinguish between the presentation and application layers. The application programs that allow users to interact with the network operating system operate at this level of the NetWare stack, which employ protocols that are used by IPX and SPX to enable network and internetwork

NetWare core protocols (NCP)
NetBIOS (optional)
SPX (sequenced packet exchange)
SAP (service advertising protocol)	IPX (Internet packet exchange)	RIP (routing information protocol)
ODI (open datalink interface) Access protocol (Ethernet, Physical media)

The IPX/SPX protocol.