PAR - Lesson 1.pdf

MODULE 1: NETWORKING TODAY 1 Introduction 2 1.1 Networks affect our lives Networks Connect Us: 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 li...

MODULE 1: NETWORKING TODAY 1 Introduction 2 1.1 Networks affect our lives Networks Connect Us: 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. No boundaries: ○ World without boundaries ○ Global communities ○ Human network 3 1.2 Elements in communication 1) Source; 2) Sender; 3) Message; 4) Channel/Medium; 5) Receiver; 6) Destination 7) Understanding; 8) Response/Feedback. 4  Act. 1.1 ► Identify the different elements in the next communication processes: ► A phone call. Elements in ► TV broadcast. communication ► Computer network. process ► Postal system. 5 1.3 Understanding Before starting a communication, it is needed to establish some rules and protocols. A communications protocol is a set of formal rules describing how to transmit or exchange data, especially across a network. 6 1.4 Computer networks Every computer network has these different elements: Devices ○ End devices ○ Intermediary network devices Channels or medium ○ Metal wires ○ Glass or plastic fibers ○ Wireless (EM medium) Protocols 7 1.5 End devices An end device is where a message originates from or where it is received. Data originates with an end device, flows through the network, and arrives at an end device. 8 1.6 Intermediary network devices An intermediary device interconnects end devices. Examples include switches, wireless access points, routers, and firewalls. Management of data as it flows through a network is also the role of an intermediary device, including: Regenerate and retransmit data signals. Maintain information about what pathways exist in the network. Notify other devices of errors and communication failures. 9 1.7 Types of communication A communication can be: Client-server: ○ Every computer on a network is called a host or end device. ○ Servers are computers that provide information to end devices. ○ Clients are computers that send requests to the servers to retrieve information. Peer-to-Peer: ○ It is possible to have a device be a client and a server in a Peer-to-Peer Network. ○ This type of network design is only recommended for very small networks. 10 Common types of Networks 11 1.8 According to its size According to its size, a network can be: ○ BAN: Body area networks ○ PAN: Personal area networks ○ LAN: Local area networks ○ MAN: Metropolitan area networks ○ WAN: Wide area networks 12 Act 1.2 Give two examples of every type of networks, according to its size: Types of BAN networks PAN LAN MAN WAN 13 1.9 According to its transmission technology Broadcasting networks: ○ it is a method of transferring a message to all recipients simultaneously unicast: to one multicast: to some broadcast: to all Switching networks: ○ Information travels from one point to another Packet switching Circuit switching Message switching 14  Imagine a teacher explaining Act. 1.3 networking in class. This type of communication is considered a broadcasting network. Why? Broadcasting In that same scenery, find an example for: ○ an unicast message ○ a multicast message ○ a broadcast message 15 1.10 Switching networks (I) Packet switching: The message is divided in small packets, that are sended independently using different routes. 16 1.10 Switching networks (II) Circuit switching: A route is reserved for the whole transmission. 17  Act. 1.4 Researching work: Look for advantages and Pros and cons disadvantages of each type of switching communication. 18 Reliable Networks 19 1.11 Network architecture Network Architecture refers to the technologies that support the infrastructure that moves data across the network. There are four basic characteristics that the underlying architectures need to address to meet user expectations: Fault Tolerance Scalability Quality of Service (QoS) Security 20 1.12 Fault tolerance A fault tolerant network limits the impact of a failure by limiting the number of affected devices. Multiple paths are required for fault tolerance. This is not possible with circuit-switched networks which establish dedicated circuits. 21 1.13 Scalability A scalable network can expand quickly and easily to support new users and applications without impacting the performance of services to existing users. Network designers follow accepted standards and protocols in order to make the networks scalable. 22 1.14 Quality of Service (QoS) Quality of Service (QoS) is the primary mechanism used to ensure reliable delivery of content for all users. With a QoS policy in place, the router can more easily manage the flow of data and voice traffic. 23 1.15 Network security There are two main types of network security that must be addressed: Network infrastructure security Information Security Three goals of network security: Confidentiality Integrity Availability 24 What did I learn in this module? 25 You learnt: What a communication is. Elements in a communication process. What a computer network is. Common types of computer networks. Different switching networks. Reliable networks. 26