Computer Network & Security CPE 8 PDF

2/7/25 CHAPTER 1 COMPUTER NETWORK NETWORKING & SECURITY FUNDAMENTALS CPE 8 1...

2/7/25 CHAPTER 1 COMPUTER NETWORK NETWORKING & SECURITY FUNDAMENTALS CPE 8 1 2 NETWORKING CONCEPTS NETWORKING CONCEPTS Networking involves the exchange DEVICES can include of DATA between DEVICES or nodes computers, servers, connected to a network. smartphones, IoT(Internet of Things) devices, and more. 3 4 NETWORKING CONCEPTS Key networking concepts include: 1 The DATA is transmitted over Network Topology - The physical or logical various mediums, such as layout of a network, describing how devices are copper cables, fiber optic arranged and connected. Common topologies cables, or wireless signals, 2 include bus, star, ring, mesh, and tree. using standardized protocols that govern how the data is Network Protocols - Sets of rules and conventions packaged, addressed, and that define how data is formatted, transmitted, and delivered. received over a network. Examples include TCP/IP, HTTP, FTP, and SMTP. 5 6 1  2/7/25 Key networking concepts include: Key networking concepts include: 3 5 OSI Model - A conceptual framework that Network Security - Measures taken to protect standardizes the functions of a networking or the confidentiality, integrity, and availability telecommunication system into seven distinct layers, of data transmitted over a network, including each with its own responsibilities and protocols. firewalls, encryption, and access control. 4 IP Addressing - A unique identifier assigned to each device on a network, enabling data to be routed to its intended destination. IPv4 and IPv6 are the two main versions of IP addressing. 7 8 1970-1980 Local Area Networks (Lan) emerged. Ethernet, a popular LAN technology was developed during this period. HISTORY OF NETWORKING 1990s The World Wide Web (WWW) was invented. The introduction of web browser HTML made the internet more accessible. 9 10 2000s Wireless networking technology, such as Wi-Fi and cellular networks, gained prominence. Enabling to rise the use of mobile and smartphones. Layers of 2010s The Internet of Things (IoT) has taken the stage. Billions of devices connecting and OSI Model exchanging data in the internet. Cloud computing, edge computing and Software-defined network (SDN) emerged as the key trends. 11 12 2  2/7/25 OSI Model The OSI (Open Systems Interconnection) Model is a set of rules that explains how different computer systems communicate over a network. OSI Model was developed by the International Organization for Standardization (ISO). 13 14 The highest layer of the OSI model, and the The main role of the Presentation Layer is to closest to the end-user, all kinds of services ensure the incoming data is in an like web browsers, email, and more appropriate, presentable form for the happen on layer 7. While recipient. Layer 6 is responsible for converting applications themselves may not be part of and formatting the machine-readable code this layer, the services they offer always are. into a form the end-user can understand and That’s why layer 7 is the most use in the application layer. Data encryption vulnerable when it comes to cybersecurity. also happens in this layer. 15 16 The Session Layer, sometimes called the The Transport Layer manages the “port layer”, facilitates the setting up and transportation of data, facilitating a reliable taking down of connections between two arrival of data while also providing error- endpoints. When two endpoints are checking functions and data flow controls. communicating with each other, it’s called There are two main protocols associated with the transport layer: a “session”, hence the name of the layer. 1.TCP (Transmission Control Protocol) 2.UDP (User Diagram Protocol) 17 18 3  2/7/25 The Network Layer routes and reroutes data The Data Link layer of the OSI model through various physical networks, facilitating data transmission to its destinations. In practice, routers essentially receives and transmits packets make decisions on where to route the data based of information from and to the physical on information provided by layer 3. Once data is network devices. It manages how much received, the IP (Internet Protocol) address is data should be allowed to be transferred added to the device by the network layer, which to the next layer and assesses possible tells the data packet where it should go. errors in data transmission. Layer 6 can also be divided into two sub-layers: 1.Logical Link Control (LLC) 2.Media Access Control (MAC) 19 20 The OSI layer 1, physical layer, is the bottom layer in the OSI model, and as the name suggests, covers the physical components of the network https://www.youtube.com/w or computing system: cables, atch?v=Ilk7UXzV_Qc&t=326s routers, endpoints, etc. 21 22 4