Tutorial 18

Name the three basic elements required to create a network.

The three basic elements required to create a network are connection, communication, and services.

The primary benefit of a LAN is its ability to share resources. Name some of the other benefits of networking.

In addition to the ability to share resources, LANs are resilient, act as communication gateways, and facilitate electronic mail.

What is the difference between a peer-to-peer and a server-based network?

In a peer-to-peer network, each computer acts as a server or a client depending on the user's needs. Each user, or workstation, establishes its own security and determines which resources are available to other users.

In a server network, a central server (dedicated computer) manages access to all shared files and peripherals. This is a secure environment suitable for most organizations.

Name the three network topologies.

The three network topologies are star, bus, and ring.

What type of cabling do thin Ethernet and UTP cabling require?

Thin Ethernet uses a round BNC connector and UTP uses an RJ-45 connector (similar to a telephone jack).

What is the function of a network interface card?

Network interface cards (NICs) link the computer to the network cable system. They provide the physical connection between the computer's expansion bus and the network cabling.

Name the three main types of network cabling. What are their advantages?

• Twisted-pair cable is very common, easy to install, and inexpensive.

• Coaxial cable is found in two types: thin (ThinNet) and thick (ThickNet). When compared to twisted-pair, coaxial cable is the better choice even though it costs more. It is a standard technology and resists rough treatment and electromagnetic interference (EMI). Although more resistant, it is still susceptible to EMI and eavesdropping.

• Fiber-optic cable is made of light-conducting glass or plastic fibers. It carries data signals in the form of modulated pulses of light. Although it is no less expensive (in both installation and cable cost) than twisted-pair or coaxial cable, it has advantages. It is immune to EMI or detection outside the cable. It supports very high bandwidths (the amount of information the cable can carry) and can handle thousands of times more data than twisted-pair or coaxial cable.

What is the purpose of network protocols?

A network protocol is a set of rules governing the way computers communicate over a network. In order for computers using different software to communicate, they must follow the same set of networking rules and agreements, or protocols. A protocol is like a language. Unless both computers trying to communicate are "speaking" and "listening" in the same language, no communication will take place.

Describe the functions of a router, a bridge, and a gateway.

Bridges work like repeaters but offer additional advantages. They can isolate network traffic or problems. The traffic within a segment will not be sent to the entire network unless its destination is in another segment. Bridges can also link unlike segments (Ethernet and token ring).

Routers provide interconnectivity between like and unlike devices on the LAN and WAN. Routers work like bridges, but can connect networks using different protocols and can select the best route from network to network based on traffic load. Routers route data based on factors such as least-cost, minimum delay, minimum distance, and least congestion. Routers are generally used to create a wide area network and to connect dissimilar networks.

Gateways provide as much interconnectivity and even greater functionality than routers and bridges do. A gateway usually resides on a dedicated computer that acts as a translator between two completely dissimilar systems or applications. Since a gateway is both a translator and a router, it tends to be slower than bridges or routers. Gateways also provide access to special services such as e-mail or fax functions.

What is the most widely used network protocol?

TCP/IP is the most widely used network protocol. It is the protocol of the Internet.

What is the difference between a LAN and a WAN?

A LAN is a local area network; it is usually confined to a limited space such as a building or a room. A WAN is a wide area network and can span long distances (even worldwide).

Your network is showing signs of reduced bandwidth. What is causing this problem?

This type of problem is called a bottleneck. A bottleneck on a system is the resource that limits the rate at which a task can be completed. If your task uses the processor, network and disk resources, and spends more of its time transferring data to and from the disk, you might have a memory bottleneck. A memory bottleneck might require adding more RAM.

What is an ISP?

An ISP (Internet Service Provider) provides the connection between dial-up (modem) users and the Internet.

Name some of the most common Internet domain extensions.

Here is a table of common Internet domain extensions. How many did you get?

What does URL stand for?

URL stands for Uniform Resource Locator, the address system used on the World Wide Web.

Besides A+ Certification, what other computer-related certifications are available?

Other certifications available are Novell CNN and CNE, or Microsoft MCP and MCSE.

Name the three main types of portable computers.

The three types of portable computers are laptop, notebook, and subnotebook or palmtop computers.

What is a docking station?

Docking stations (also known as docking ports) are specialized cases that allow entire notebook computers to be inserted within them. This allows the notebook to be connected to desktop I/O devices such as full-sized keyboards, CRT monitors, and network connections.

What is the purpose of PCMCIA cards?

In order for laptop and notebook computers to have the same degree of expandability that is associated with desktop computers, the Personal Computer Memory Card International Association (PCMCIA) established several standards for credit-card-sized expansion boards that fit into small slots on laptop and notebook computers.

Describe the different PCMCIA card types.

There are four types of PCMCIA cards:

• PCMCIA Type I is the original computer-card standard and is now referred to as the Type I standard. These cards are used only for memory. Type I cards are 3.3 mm thick.

• PCMCIA Type II cards support most types of expansion devices (like communication hardware) or network adapters. Type II cards are 5 mm thick.

• PCMCIA Type III cards are primarily for computers that have removable hard disk drives. This standard was introduced in 1992. Type III cards are 10.5 mm thick, but they are compatible with Type I and Type II cards.

• PCMCIA Type IV cards are intended to be used with hard disk drives that are thicker than the 10.5-mm Type III card.

How do you configure a computer card?

PCMCIA (PC-Card) is part of the Plug and Play standard. Plug and Play-compatibility means being able to add components without turning off or rebooting the computer. PCMCIA buses are not configured with jumper settings (because they don't have any) but with software.

What are the two kinds of displays found on laptop computers?

The two types of displays found on laptop computers are active-matrix and dual-scan.

Why is heat dissipation a concern in computer-chip technologies for portable computers?

In desktop systems, CPU heat is dissipated with the use of cooling fans housed inside the case. There is no room for this solution in a portable system, so manufacturers have addressed this problem in the packaging of the chip itself.

With the exception of Macintosh, what drives are standard in a portable computer?

Except for the size and packaging, hard disk drive technology is similar to desktop technology. EIDE drives are standard in portables, with the exception of Macintosh, which uses SCSI.