CompTIA A+ Rapid Review: Networking

Objective 2.8: Identify various types of networks

When people are talking about a network they are usually talking about a local area network in a single location. However, there are several other types of networks. As a PC technician, you don’t necessarily need to be an expert in all the different types of networks, but you should understand the terminology used. Most local area networks are configured in a star topology, but there are other types, and you’re expected to know what differentiates each type.

Exam need to know...

• LAN

  For example: What is a LAN?

• WAN

  For example: What is the primary characteristic of a WAN?

• PAN

  For example: Where is a PAN located?

• MAN

  For example: What is the difference between a MAN and a WAN?

• Topologies

  For example: What are the different topologies? Which topology provides the best fault tolerance?

LAN

A local area network (LAN) is a network in a single location. Devices connected to the LAN can access network resources such as servers and printers.

True or false? A LAN is the primary type of network used in a SOHO.

Answer: True. A SOHO network would be in a single location and is a LAN.

A LAN can include multiple networks (sometimes called subnets). For example, an organization could have one network for servers, one network for people in the Sales department, and another network for all other employees. Within each network, all of the devices are connected with switches. Within the organization, one or more routers connect the different networks and provide a path to the Internet.

WAN

A wide area network includes two or more LANs geographically separated. For example, a company might have a LAN in Virginia Beach and another LAN in New York. If they connect the two LANs, they are creating a WAN.

True or false? A WAN includes networks that can cover a large physical distance.

Answer: True. WANs can include networks in different cities, states, countries, or regions. The key is that they are geographically separated.

PAN

A personal area network (PAN) is a network of devices that are connected around a person. For example, a person might have a smartphone and a tablet device with wireless capabilities, and a mobile hotspot used to connect to a cellular network. After turning on the hotspot, they can use it to connect to the Internet with the smartphone and their tablet.

True or false? A PAN can include devices in a separate building within a single campus.

Answer: False. A PAN is centered around a single individual only. While the signals might travel farther than a few feet around a person, the PAN is still focused on the person.

MAN

A metropolitan area network (MAN) is a group of networks in the same geographical location but spread across a wide area. For example, a university campus that has connected networks throughout several buildings is a MAN.

True or false? The MAN and WAN are essentially the same.

Answer: False. A WAN includes LANs that are separated by a large physical distance, but a MAN includes networks that are in the same general geographical location.

The difference between a LAN and a MAN is that a LAN is within a single building, while a MAN will span multiple buildings.

Topologies

Computers are organized within a network by using different network topologies. A topology refers to how the devices are logically connected, and the most common topology is the star topology.

True or false? A mesh topology provides redundancy for each network device.

Answer: True. A mesh topology includes multiple redundant connections for each device in the network. If any single connection fails, the device can tolerate the failure and continue to communicate with devices by using other connections.

True or false? A bus topology provides redundancy with a MAU.

Answer: False. A bus topology does not have any redundancy. If a single connection fails, the entire network fails. Token ring networks often use a multistation access unit (MAU) for redundancy. The four primary topologies are star, ring, mesh, and bus. Figure 2-2 shows diagrams of each, and they are defined as follows:

• In a star topology, devices connect to each other through a central network distribution device such as a hub or a switch.

• In a ring topology, devices are connected in a physical or logical ring. A logical token is passed to each device in turn, and devices can transmit only when they have the token. Some token rings use a central MAU to eliminate the possibility of a single device failing and breaking the ring.

• A mesh topology includes multiple connections. In a full mesh network, every single device has connections to every other device in the network.

• A bus network connects devices in a line. Each end of the bus must be terminated. If a terminator is removed, all devices stop communicating. Similarly, if the bus has a failed connection anywhere on the bus, it results in two separate segments that each have only a single terminator. That is, any break in the bus stops communication for all devices.

A hybrid network uses a combination of any two or more topologies.

Figure 2-2 Topologies.

Can you answer these questions?

You can find the answers to these questions at the end of this chapter.

1. What type of network is centered around an individual?

2. What type of network connects multiple networks located in separate geographical locations?

3. What network topology provides the most redundancy?