CompTIA A+ Rapid Review: Networking

The Networking domain covers approximately 27 percent of the A+ 220-801 exam. Almost every computer you’ll service will be connected to a network, so it’s important to understand some basic networking topics. This includes network cables and connectors, network devices such as routers and switches, wireless connections, and common protocols used to control traffic over a network. Many networks use both wired and wireless connections, along with a router for Internet access. Technicians are often asked to help configure connectivity for different types of networks, and they need to know the functions and features of various devices, along with appropriate networking tools.

This chapter covers the following objectives:

• Objective 2.1: Identify types of network cables and connectors

• Objective 2.2: Categorize characteristics of connectors and cabling

• Objective 2.3: Explain properties and characteristics of TCP/IP

• Objective 2.4: Explain common TCP and UDP ports, protocols, and their purpose

• Objective 2.5: Compare and contrast wireless networking standards and encryption types

• Objective 2.6: Install, configure, and deploy a SOHO wireless/wired router using appropriate settings

• Objective 2.7: Compare and contrast Internet connection types and features

• Objective 2.8: Identify various types of networks

• Objective 2.9: Compare and contrast network devices and their functions and features

• Objective 2.10: Given a scenario, use appropriate networking tools

Objective 2.1: Identify types of network cables and connectors

The first objective in this domain introduces the three most common types of cables used for networks: fiber, twisted-pair, and coaxial. The most important thing you should know for this objective is the types of connectors used with each type of cable. The next objective builds on these topics requiring you to know the characteristics of the cables.

Exam need to know...

• Fiber

  For example: What types of connectors are used with fiber cable?

• Twisted-pair

  For example: What types of connectors are used with twisted-pair cable? What standards are used when wiring a twisted-pair cable?

• Coaxial

  For example: What are the two common connectors used with coaxial cable?

Fiber

Fiber cable is made of a flexible glass material, and data is sent over the cable as light pulses. There are three primary connectors you’ll see with fiber cables.

True or false? An LC is one of the common connectors used with fiber cable.

Answer: True. A Lucent Connector (LC) is used with fiber cable.

Some additional connectors commonly used with fiber cable include the following:

• Square connector (SC). Just as its name implies, this connector is square shaped. The LC connector is a miniature version of the SC connector.

• Straight tip (ST). This is a round connector with a straight tip.

Twisted-pair

Twisted-pair cable includes multiple pairs of wires twisted around each other. These twists are precise and determine the frequency capabilities of the cable. Cables that support higher frequencies allow the cable to transmit more data at a time.

True or false? RJ-11 connectors are used with twisted-pair cables to connect network devices.

Answer: False. RJ-45 connectors are used with twisted-pair cables when connecting network devices.

RJ-11 connectors are used with phone-based twisted-pair cables. For example, RJ-11 connectors are used with a plain old telephone system (POTS) modem or even a digital subscriber line (DSL) modem.

Twisted-pair cables used in networking have four pairs of wires. The colors of each pair are as follows:

• Blue wire and white wire with a blue stripe

• Orange wire and white wire with an orange stripe

• Green wire and white wire with a green stripe

• Brown wire and white wire with a brown stripe

Each wire should be connected to a specific pin on the RJ-45 connector, and there are two standards that can be used—T568A and T568B. When creating a standard cable, both ends should use the same standard. This ensures that the same wire is going to the same pin on each connector.

True or false? A cable wired with the T568A standard on one end and the T568B standard on the other end works as a crossover cable.

Answer: True. If different standards are used, certain wires are crossed over and the cable will function as a crossover cable. Crossover cables are used to connect similar devices together, such as two computers or two switches.

Coaxial

Coaxial cable is commonly used to connect televisions with broadband cable, DVD players, and digital video recorders (DVRs). It isn’t used as often with networks, but it has been used in the past.

True or false? F-type screw-on connectors are used with coaxial cable.

Answer: True. Coaxial cable uses F-type screw-on or BNC twist-on connectors.

Can you answer these questions?

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

1. What type of cable would an LC connector be used with?

2. What is the difference between an RJ-11 and an RJ-45 connector?

3. What type of cable is used with an F-type connector?