CS407 Official Handouts

Handouts for CS407: Routing and Switching

Topic 1: Routing and Switching - Course Information

This topic provides motivation to study this course. The focus of this course is education and to help you develop a real understanding of networking, not merely memorizing facts and commands. We have divided this course into three parts:

1. Network Fundamentals

In this part, you will learn both the practical and conceptual skills that build the foundation for understanding basic networking.

2. Routing Protocols an Concepts

The focus of this part is on learning the architecture, components, and operations of routers, and explains the principles of routing and routing protocols.

3. Switching Techniques

The focus of this part is on learning the architecture, components, and operations of a converged switched network. By the end of this course, you will be able to build simple LANs, perform basic configurations for routers and switches, and implement IP addressing schemes. Figures and Materials used have been adapted from " unless stated otherwise.

Topic 2: Components of a Network

Among all of the essentials for human existence, the need to interact with others ranks just below our need to sustain life. Communication is almost as important to us as our reliance on air, water, food, and shelter. In today's world, through the use of networks, we are connected like never before. People with ideas can communicate instantly with others to make those ideas a reality. News events and discoveries are known worldwide in seconds. Individuals can even connect and play games with friends separated by oceans and continents. Networks connect people and promote unregulated communication. Everyone can connect, share, and make a difference.

Networks support the way we learn

Communication, collaboration, and engagement are fundamental building blocks of education. Institutions are continually striving to enhance these processes to maximize the dissemination of knowledge. Access to high quality instruction is no longer restricted to students living in proximity to where that instruction is being delivered. Online distance learning has removed geographic barriers and improved student opportunity. Online (e-learning) courses can now be delivered over a network. These courses can contain data (text, links), voice, and video available to the students at any time from any place. Online discussion groups and message boards enable a student to collaborate with the instructor, with other students in the class, or even with students across the world. Blended courses can combine instructor-led classes with online courseware to provide the best of both delivery methods.

Network Components: Clients and servers

All computers connected to a network that participate directly in network communication are classified as hosts or end devices. Hosts can send and receive messages on the network. In modern networks, end devices can act as a client, a server, or both. The software installed on the computer determines which role the computer plays. Servers are hosts that have software installed that enable them to provide information, like email or web pages, to other hosts on the network. Each service requires separate server software. For example, a host requires web server software in order to provide web services to the network. Clients are computer hosts that have software installed that enable them to request and display the information obtained from the server. An example of client software is a web browser, like Internet Explorer.

Peer to Peer

Client and server software usually runs on separate computers, but it is also possible for one computer to carry out both roles at the same time. In small businesses and homes, many computers function as the servers and clients on the network. This type of network is called a peer-to-peer network. The simplest peer-to-peer network consists of two directly connected computers using a wired or wireless connection. Multiple PCs can also be connected to create a larger peer-to-peer network but this requires a network device, such as a hub, to interconnect the computers. The main disadvantage of a peer-to-peer environment is that the performance of a host can be slowed down if it is acting as both a client and a server at the same time. The advantages of peer-to-peer networking: Easy to set up Less complexity Lower cost since network devices and dedicated servers may not be required Can be used for simple tasks such as transferring files and sharing printers The disadvantages of peer-to-peer networking: No centralized administration Not as secure Not scalable All devices may act as both clients and servers which can slow their performance

Networks Components

The network infrastructure contains three categories of network components: Devices Media Services

End Devices

The network devices that people are most familiar with are called end devices, or hosts. These devices form the interface between users and the underlying communication network. Some examples of end devices are: Computers (work stations, laptops, file servers, web servers) Network printers VoIP phones TelePresence endpoint Security cameras Mobile handheld devices (such as smartphones, tablets, PDAs, and wireless debit/credit card readers and barcode scanners)

Intermediary Network Devices

Intermediary devices interconnect end devices. These devices provide connectivity and work behind the scenes to ensure that data flows across the network. Intermediary devices connect the individual hosts to the network and can connect multiple individual networks to form an internetwork. Examples of intermediary network devices are: Network Access (switches and wireless access points) Internetworking (routers) Security (firewalls)