Internetwork Packet Exchange/Sequenced Packet Exchange

Like TCP/IP and AppleTalk that are also discussed in this chapter, IPX/SPX is not a single protocol but rather a protocol suite. IPX/SPX was created by Novell for use on Novell networks. When Novell had a larger presence in the network arena, so too did the IPX/SPX protocol suite. Today, the popularity of IPX/SPX has yielded to TCP/IP although it is still used in some network environments enough. TCP/IP's suitability for large multisite networks and its general acceptance has now even led Novell to adopt TCP/IP as the protocol of choice. Table 3 shows some of the protocols that comprise the IPX/SPX suite and their functions.

3 IPX/SPX Protocols and Their Functions



Related OSI Layer(s)

Internetwork Packet Exchange (IPX)

A connectionless transport protocol that is primarily responsible for logical network addressing, route selections, and connection services.

Network, Transport

NetWare Link State Protocol (NLSP)

NLSP uses a link-state route discovery method to build routing tables.


NetWare Core Protocol (NCP)

NCP is a connection-oriented protocol that provides the connection between clients and services.

Application, Presentation, Session

Routing Information Protocol (RIP)

Similar to the routing protocol used with TCP/IP, RIP is responsible for the routing of packets on an IPX/SPX network.


Service Advertising Protocol (SAP)

SAP allows systems providing services to the network, such as file and print services, to announce their services and addresses to the network.

Application, Presentation, Session

Sequenced Packet Exchange (SPX)

SPX is a connection-based protocol used when guaranteed message delivery is required on the network.