Chapter 22: Basic Networking

In Chapter 21, you were introduced to some of the important cables and connectors that are used to link computers and peripherals; many of the topics discussed were intended to prepare you for basic networking. In Chapter 22, we will focus on the various types of networks—the communication methods computers use to talk to each other—and some of the important hardware used in various network typologies. We will also focus on troubleshooting network-related connectivity issues, as well as harmful threats that may come in the form of an uneducated user or a computer virus.

It is very important for anyone studying networking architecture and concepts to be familiar with the IEEE 802 specifications for networking components and the Open Systems Interconnect (OSI) reference model, which provides a set of standards for computers to communicate with each other. These two topics are the foundation on which networks are based. However, it is unlikely that the A+ Core exam will tax you with detailed questions on these two topics. The IEEE 802 standards that you may need to know for the exam will be identified.

IEEE 802 SPECIFICATIONS

The IEEE is a technical organization that develops standards for Local Area Networks (LANs) and Wide Area Networks (WANs). The IEEE 802 project standards were developed in the 1970s as a set of specifications, or rules, that manufacturers and users can use as a sort of road map for understanding and developing networks and network-related devices. The IEEE specifications are associated with certain networking layers of the OSI networking model, which is discussed in this chapter.

Throughout this book, you have been introduced to many of the IEEE standards and the particular technologies to which they apply. For example, in Chapter 21, you were introduced to the IEEE standard 1394, which applies to high-speed serial transmission, as well as the IEEE 1284 standard, which applies to parallel transmission. Project 802 was developed to address standards for NICs, network cables, and WANs. There have been many additions and addendums added to the IEEE 802 standards as technology has progressed.

The 12 categories of the 802 specifications and their associations are as follows:

• 802.1—Internetworking

• 802.2—The Logical Link Control (LLC) sublayer of the OSI networking model

• 802.3—Carrier Sense Multiple Access/Collision Detection (CSMA/CD) LANs (Ethernet)

• 802.4—Token bus LAN

• 802.5—Token Ring LAN

• 802.6—Metropolitan Area Network (MAN)

• 802.7—Broadband Technical Advisory Group

• 802.8—Fiber Optic Technical Advisory Group

• 802.9—Integrated voice and data networks

• 802.10—Network Security Technical Advisory Group

• 802.11—Wireless networking

  • 802.11a—Applies to 5GHz wireless technology, commonly at 6Mbps, 12Mbps, or 24Mbps transmission rates.

  • 802.11b—Applies to 2.4GHz wireless technology at 11Mbps per second transmission rate.

  • 802.11g—Also applies to 2.4GHz wireless technology range and offers wireless transmission rates up to 54Mbps.

• 802.12—Demand priority access LAN 100BaseVG, any LAN

The three IEEE 802 standards that are most important for A+ study purposes are: 802.3, which represents Ethernet; 802.5, which refers to Token Ring or token passing; and 802.11, which refers to wireless networking. Later in this chapter, we will discuss topologies, such as bus, star, and ring. It is important to remember that the 802.3 Ethernet standards apply to bus and star networks that utilize CSMA/CD access methods, whereas Token Ring topologies utilize token-passing methods to place a data signal on a wire.

As mentioned earlier, the IEEE 802 standards apply mostly to the physical aspects of networking components. For example, they have to do with how a NIC is connected to a network or what types of media transmission methods are used to carry a signal down a physical wire.

Just about every networking component manufactured today is designed to meet one of the above-mentioned IEEE standards. If you purchase a hub, cable/DSL router, NIC, or wireless network component, take a look at the specifications on the package or in the advertisement. You will see that the product was manufactured to meet one of the standards set forth by the IEEE.

For more information regarding the IEEE standards and updates to these standards, please visit the IEEE home page located at: http://www.ieee.org/portal/index.jsp.