Chapter 1: Computer Network
Fundamentals
Core Idea
A (computer) network is an interconnection of two or more computing devices. How the devices
connect is described as bythe network topology. The implementation of the topology is
dependent on technologies chosen for their appropriateness, performance, and cost.
Instructor Focus
The focus of this topic is an establishment of the definition of a network itself and the common
terminology used to describe the elements of a network. The rest of the topic is focused on the
Network+ Exam Objective for this Chapter/Lesson
x 1.5 Compare and contrast the characteristics of network topologies, types, and technologies
Terminology
Make an effort to define the following terms for the designated areas. After defining these,
calling on the students for repeat definitions as you progress through the slide deck will help
them retain the terminology.
Network Elements:
Client vs Server
Hub vs Switch
Geographical Network Designations:
LAN
WAN
CAN
MAN
Network Hierarchies:
Client/server
Peer to peer
Network Topologies:
Star (Wired and Wireless)
Bus
Focus Questions
x What is the purpose of a network?
x What are some examples of network components?
x How are networks defined by geography?
Icebreaker Discussion
Choose one or both of the following:
1. What components are required to create a network?
This should be asked to elicit thought on what computer networking is and the myriad
possibilities for interconnection that exists today. By asking this question, you can also get
2. What information is most important to describing a network?
Icebreaker Activity
1. Diagram a network and describe the network components. How would you classify this
network?
This activity will give you a good idea of the individual backgrounds that the students have in
terms of networking; collecting and reviewing these assignments will help you assess where
Main Activities
1. Network Overview
For this activity, start with a diagram of two clients on the board with a substantial space
between them, such as the following. (Clip Art of the computer system is available from
www.office.com; all other elements used were shapes available in Word.)
Ask them, how do you propose that this media should work to both send and receive data.
Should it be able to send and receive simultaneously? Conversely should the machines have to
receive first and then send a response after all the data is finished, waiting for their turn?
Such questions as this are what the early network inventors had to grapple with. They also had
to grapple with the limitations of the media that was available for them to use.Next, ask how to
add the third machine into the network. Get a variety of suggestions for this, but any of them
will suffice at this point as long as all three machines are coupled together. Take this opportunity
As a final step to this activity, add a cloud diagram that represents the Internet or other network
resources. Now ask your students how to connect the small network to the cloud network.
There are several ways you should explore: (1) Each computer could have its own connection to
At this point, discuss the need to have bidirectional communication links among the machines to
connect to the Internet from a single machine; the ring organization is now ineffective for
2. Networks by Geography
Describe the different network topologies (these are included in the PowerPoint slide deck). For
each example, you should identify elements you are likely to find included in the network type:
LAN: Small offices/home networks (SOHO networks) are what most people think of as a
LAN. These will likely include networked printers, laptops, desktop computers, and most
likely a wireless router (to create a WLAN). LANs also exist in large organizations and
can have thousands of users on the same campus, often called a Campus Area Network
(CAN).
3. Topology Exploration
For the next activity, have your students act as a ‘star’ network. This will allow you to explore
2. Describe the connection process such as all nodes connected to a switch.
4. Provide a message tothe sender. Have the sender raise his hand to get your
attention. You then direct him to provide the message to you and to point at who
5. Add the new node to the network, describing the changes in routing that have to
take place to connect the new node.
7. Set up the next network in the list.
Although the Bus and Ring Topologies were used at one time, they are rarities now, so they will
not be used in this demonstration. Students should, however, refer to them in the text so that
they have some awareness of these early technologies.
Chapter 1 Network Simulator Activity
Drag & Drop Activity: Network Topologies
4. Client/Server and Peer-to-Peer Discussion
Outline the client/server paradigm and compare and contrast it to the peer-to-peer (P2P)
paradigm as a final discussion before review of the core concepts. Help them understand that
although some servers are large computers, a server can be any device that provides a service.
A router provides a type of ‘connection service’, as does a switch. A DHCP service is loaded into
every Wireless Access Point, whether it is a $20 model or a $1000 one.
Quiz Questions
You can ask the following questions either in class for a group discussion or for individual practice. If
you ask them for individual practice, review the answers in class to make sure that everyone
properly understands the content.
1. What components are required for a network to exist for three or more devices?
The answers on this may vary, but in addition to the devices (such as computers) that will
connect to each other, you need a media for connection with a means to deliver a signal, a
2. What affects the relative scalability of hub, bus, and ring topologies? (Note, don’t assume that
they know what the word ‘scalability’ refers to. Also, when discussing these devices, it is an
opportunity to provide hints about what is coming up in the discussions of Ethernet LANs thus
baiting them for additional learning to come.)
Hub: A hub simply repeats whatever it gets to all other connected components. The device itself
is limited only by the number of ports it has for broadcast. It will create additional messages on
the network because it does not discern a recipient. Hubs are not manufactured for mass use
3. What are the factors that should be considered for deciding on a logical network topology?
One of the primary considerations should be the optimization of the path of messages from one
4. What are the main advantages and disadvantages of full-mesh topologies and partial-mesh
topologies?
The advantage of a full-mesh topology is the high redundancy, which provides the most reliable
connectivity between any two nodes; the likelihood of being able to connect two random nodes
5. What are the main differences between a client/server network and a peer-to-peer network?
Again, the answers here may vary, but the primary difference is the hierarchical relationship in a
client/server system and the equal party relationship with peer to peer. The centralization of