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 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 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.