Computer Networks 2024-2025 Past Paper PDF

Salahadden-Halwer University Computer Department College of Science Third Stage- CS & IT Computer Networks Academic Year 2024-2025...

Salahadden-Halwer University Computer Department College of Science Third Stage- CS & IT Computer Networks Academic Year 2024-2025 Lecturer Zanco Asaad Taha http://tiny.cc/net2024  Lecture Outlines 1. What is Computer Network? 2. Why Computer Networks? 3. Overview of Network Components. 4. Network Types. 5. Network Topology 25/09/2024 2 What Is Computer Network? Network is a group of connected devices, such as computer and printer, that communicate either wirelessly or via a cable for sharing resources. 25/09/2024 3  Why Computer Networks? Reasons Communication: Networks enable a variety of communications, including video conferencing, real-time chats, and email. Sharing hardware: Printer is the best example of hardware sharing. Sharing data: Linking users on the same system makes it easy for them to share files with others on the network. Sharing applications: Networking makes it possible for numerous users to share a single application. Data backup and retrieval: A network makes it possible to store data in a central location. When the data is in a central location, it is easier to back up and retrieve. 25/09/2024 4 Overview of Network Components 25/09/2024 5 Overview of Network Components- Cont. Client: The term client defines the device an end user uses to access a network. This device might be a workstation, laptop or smartphone with wireless capabilities. Server: A server , as the name suggests, serves up resources to a network. These resources might include e-mail access as provided by an e-mail server. Hub: A hub is an older device that interconnects network components, such as clients and servers. Switch: Like a hub, a switch interconnects network components, and they are available with a variety of port densities. 25/09/2024 6 Overview of Network Components- Cont. Router: is a network device that interconnects two or more networks. Media: The network devices need to be interconnected via some sort of media. This media could be wired such as copper cable, fiber-optic cable or wireless such as radio waves. WAN link: Today, most networks connect to one or more other networks. For example, if your company has two locations, and those two locations are interconnected the link that interconnects those networks is typically referred to as a wide-area network (WAN) link. 25/09/2024 7 Network Types: Networks Defined by Geography Local-area network (LAN) Wide-area network (WAN) Campus-area network (CAN) Metropolitan-area network (MAN) Personal-area network (PAN) 25/09/2024 8 LAN: Local Area Network LAN : A LAN interconnects network components within a local region (for example, within a building). Examples of common LAN technologies you’re likely to encounter include Ethernet (that is, IEEE 802.3) and wireless LAN networks (that is, IEEE 802.11). IEEE stands for the Institute of Electrical and Electronics Engineers , and it is an internationally recognized standards body. 25/09/2024 9 A LAN Network 25/09/2024 10 WAN: Wide Area Network WAN :A WAN interconnects network components that are geographically separated. For example, a corporate headquarters might have multiple WAN connections to remote office sites. 25/09/2024 11 MAN: Metropolitan Area Network MAN :A MAN is confined to a certain geographic area, such as a city. A MAN is almost always bigger than a LAN and usually smaller than or equal to a WAN. ‫لە بچووک لۆ گەورە‬ 25/09/2024 12 CAN: Campus Area Network CAN :A CAN is a network that spans a defined single location (such as an office complex with multiple buildings or a college campus) but is not large enough to be considered a MAN. 25/09/2024 13 PAN: Personal Area Network PAN :A PAN is a network whose scale is even smaller than a LAN. As an example, a connection between a PC and a digital camera via a universal serial bus (USB) cable could be considered a PAN. A PAN, could be a wireless connection. Bluetooth connection between your cell phone and your car’s audio system is considered a wireless PAN (WPAN). 25/09/2024 14 Network Topology : The network topology refers to the layout of a network. Topologies in use today: ❖ Bus. ❖ Star. ❖ Ring. ❖ Mesh. 15 Bus Topology 16 Bus Topology Uses a single length of cable. Devices connect directly to the cable. The cable must be terminated at both ends via T Connector. Bus topologies were popular in early Ethernet networks. 17 Star Topology 18 Star Topology Devices connect to a central point (Hub or Switch). Each system uses an individual cable to attach. Multiple stars can be combined to create a hierarchical star. Star topologies are most commonly used with Ethernet technologies. ‫چ کاتەک سیستەمەکە کار ناکات ؟ کتێک سویچ یان هەب هەرنەکات‬ 19 Ring Topology 20 Ring Topology Devices are interconnected by connecting to a single ring, or dual ring in some cases. Each device on a ring includes both a receiver (for the incoming cable) and a transmitter (for the outgoing cable). Each device on the ring repeats the signal it receives. 21 Mesh Topology 22 Mesh Topology A full mesh uses point-to-point connectivity between all devices. A partial mesh uses point-to-point connectivity between devices, but not all of them. 23  Question Internet is which type of network?. 25/09/2024 24  Any Questions? 25/09/2024 25