Chapter Summary

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The following points summarize the key concepts of this chapter:

Introduction to Protocols

• Protocols in a networking environment define the rules and procedures for transmitting data.
• To send data over a network successfully requires a series of separate steps that must be carried out in a prescribed order.
• The sending and receiving computers use protocols to:

• Break data into packets.
• Add addressing information to the packets.
• Prepare the packets for transmission.
• Take the packets off the cable.
• Copy the data from the packets for reassembly.
• Pass the reassembled data to the computer.

• Several stacks are used as standard protocols; the most prominent standard protocols are based on the OSI reference model layers.
• Protocols are implemented and removed in the same manner as drivers.

TCP/IP

• TCP/IP is an industry-standard suite of protocols providing communication in a heterogeneous environment.
• The four layers of TCP/IP are the network interface layer, Internet layer, transport layer, and application layer.
• The TCP protocol works in the transport layer and provides connection-oriented communication between two computers.
• The UDP protocol works in the transport layer and provides connectionless communication between two computers.
• The network interface layer of TCP/IP maps to the physical and data-link layers of OSI.
• The Internet layer of TCP/IP maps to the network layer of OSI.
• The transport layer of TCP/IP maps to the transport layer of OSI.
• The application layer of TCP/IP maps to the session, presentation, and application layers of OSI.

NetWare Protocols

• NetWare protocols were developed before the OSI reference model and therefore do not match the OSI reference model.
• The five protocols used with NetWare are Media Access Protocol, Internetwork Packet Exchange/Sequenced Packet Exchange Protocol (IPX/SPX), Routing Information Protocol (RIP), Service Advertising Protocol (SAP), and NetWare Core Protocol (NCP).

Other Common Protocols

• Many protocols are used for networking; each has unique advantages and disadvantages.
• NetBIOS and NetBEUI are commonly used for Microsoft-based, peer-to-peer networks.
• NetBIOS and NetBEUI are nonroutable protocols.
• X.25 is a protocol for packet switching.
• AppleTalk is the protocol developed for Macintosh networks.
• DECnet is Digital Equipment Corporation's proprietary protocol stack.