Lecture-06-Computer Networks.pptx lectures

Computer lectures pptx

1. Computer Networks Lecture-06 Engr. Asim Javaid Mirpur University of Science and Technology (MUST), Mirpur AJ&K

2. Outline Introduction What is a Computer Network? Types of Computer Networks Components of a Computer Network Network Topologies OSI Model Network Communication Protocols Mirpur University of Science and Technology (MUST), Mirpur AJ&K

3. Introduction Mirpur University of Science and Technology (MUST), Mirpur AJ&K

4. What is a computer network? A computer network is a collection of interconnected devices that communicate and share resources Mirpur University of Science and Technology (MUST), Mirpur AJ&K

5. How Does a Computer Network Work? The basic concept behind a computer network is to establish a connection between multiple devices so they can exchange information and resources Mirpur University of Science and Technology (MUST), Mirpur AJ&K

6. Types of Computer Networs LAN, MAN, WAN

7. Local Area Network (LAN)

8. Local Area Network (LAN)

9. Metropolitan Area Network (MAN)

10. Metropolitan Area Network (MAN)

11. Wide Area Network

12. Wide Area Network

13. How Does a Computer Network Work? How to establish a connection ? Via Computer Networking What is computer networking? Computer Networking is the practice of connecting computers together to enable communication and data exchange between them Mirpur University of Science and Technology (MUST), Mirpur AJ&K

14. How Does a Computer Network Work? A computer network consists of several components that work together to enable communication and data sharing Key components of a computer network Nodes/Devices Network Interface Card (NIC) Cables and Connectors Wireless Access Points (WAPs) Switches Routers Modems Network Protocols Network Services Network Security Devices Mirpur University of Science and Technology (MUST), Mirpur AJ&K

15. How Does a Computer Network Work? Nodes/Devices These are the devices connected to the network, such as computers, servers, laptops, smartphones, printers, switches, routers, and other networking equipment. Each device has a unique identifier, such as an IP address or MAC address, which allows it to be identified on the network. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

16. How Does a Computer Network Work? Nodes/Devices IP Address IP address, or Internet Protocol address, is a unique numerical identifier assigned to each device connected to a computer network It serves two primary purposes Identifying the host or network interface Providing the location/addressing information for routing data packets across the network Mirpur University of Science and Technology (MUST), Mirpur AJ&K

17. How Does a Computer Network Work? Nodes/Devices MAC Address A MAC address, or Media Access Control address, is a unique identifier assigned to the network interface card (NIC) of a device. Unlike an IP address, which can change or reassigned, a MAC address is generally hardcoded into the hardware of the NIC and remains fixed throughout the device's lifetime. MAC addresses are necessary for communication within a local network Mirpur University of Science and Technology (MUST), Mirpur AJ&K

18. How Does a Computer Network Work? Network Interface Card (NIC) A Network Interface Card (NIC), also known as a network adapter or network interface controller, is a hardware component that enables a device to connect to a computer network It provides the necessary interface between the device and the network infrastructure to send and receive data Mirpur University of Science and Technology (MUST), Mirpur AJ&K

19. How Does a Computer Network Work? Network Interface Card (NIC) Mirpur University of Science and Technology (MUST), Mirpur AJ&K

20. How Does a Computer Network Work? Network Interface Card (NIC) Key aspects of a Network Interface Card Facilitates Connection to the Network Facilitates Data Transmission and Reception Has a MAC Address Requires Device Drivers Varies in Speed and Compatibility Can be Built-in or inserted into an expansion sots Mirpur University of Science and Technology (MUST), Mirpur AJ&K

21. How Does a Computer Network Work? Network Interface Card (NIC) Key aspects of a Network Interface Card Connection to the Network A NIC allows a device to connect to a network using various types of network media. This can include Ethernet cables (for wired connections), fiber optic cables, or wireless connections such as Wi-Fi. The NIC is designed to support a specific type of network connection and provides the necessary physical interface for that connection. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

22. How Does a Computer Network Work? Network Interface Card (NIC) Key aspects of a Network Interface Card Data Transmission and Reception The NIC is responsible for transmitting and receiving data between the device and the network. It converts data from the device into a format suitable for transmission over the network medium. Similarly, it receives data from the network and translates it into a format that the device can understand and process. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

23. How Does a Computer Network Work? Network Interface Card (NIC) Key aspects of a Network Interface Card MAC Address Each NIC is assigned a unique identifier called a MAC (Media Access Control) address. The MAC address is a globally unique identifier that distinguishes one NIC from another. It is embedded in the NIC's hardware and is used for identifying the device on the network. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

24. How Does a Computer Network Work? Network Interface Card (NIC) Key aspects of a Network Interface Card Device Drivers To communicate effectively with the device's operating system, the NIC requires specific software called device drivers. These drivers act as an interface between the NIC and the operating system, facilitating data transmission, configuring network settings, and handling network-related operations. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

25. How Does a Computer Network Work? Network Interface Card (NIC) Key aspects of a Network Interface Card Speed and Compatibility NICs come in various speeds, such as 10 Mbps, 100 Mbps, 1 Gbps, or higher, depending on the network standards and capabilities NICs also adhere to specific network protocols and standards, such as Ethernet, Wi-Fi (802.11 standards), or other network technologies, ensuring compatibility with the network infrastructure Mirpur University of Science and Technology (MUST), Mirpur AJ&K

26. How Does a Computer Network Work? Network Interface Card (NIC) Key aspects of a Network Interface Card Expansion Slots or Built-in NICs can be either integrated directly onto the motherboard of a device (e.g., laptops or smartphones), or they can be added externally through expansion slots on desktop computers or servers. External NICs offer flexibility as they can be upgraded or replaced, while built-in NICs provide convenience and space-saving benefits Mirpur University of Science and Technology (MUST), Mirpur AJ&K

27. How Does a Computer Network Work? Cables and Connectors Cables and connectors are essential components of a computer network infrastructure. They are used to establish physical connections between devices, enabling the transmission of data signals. Different types of cables and connectors are employed based on the specific networking requirements and the type of media being used Mirpur University of Science and Technology (MUST), Mirpur AJ&K

28. How Does a Computer Network Work? Cables and Connectors Here are some commonly used cables and connectors in computer networks Ethernet Cables: Ethernet cables are widely used for wired network connections. They typically consist of four pairs of twisted copper wires, covered in a protective sheath. The most common types of Ethernet cables are Cat5e, Cat6, and Cat6a. These cables use connectors known as RJ-45 connectors, which have eight pins and are often used to plug into network devices like computers, switches, and routers Mirpur University of Science and Technology (MUST), Mirpur AJ&K

29. How Does a Computer Network Work? Cables and Connectors Ethernet Cables Mirpur University of Science and Technology (MUST), Mirpur AJ&K

30. How Does a Computer Network Work? Cables and Connectors Fiber Optic Cables Fiber optic cables are used for high-speed, long-distance data transmission. They utilize thin strands of glass or plastic fibers to transmit data as pulses of light. Fiber optic cables offer greater bandwidth and immunity to electromagnetic interference. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

31. How Does a Computer Network Work? Cables and Connectors Coaxial Cables Coaxial cables are commonly used in cable television (CATV) networks and for connecting devices to a broadband internet service. They consist of a central conductor, surrounded by an insulating layer, metallic shielding, and an outer insulating layer. Coaxial cables use connectors such as F-type connectors for television and BNC (Bayonet Neill- Concelman ) connectors for networking applications Mirpur University of Science and Technology (MUST), Mirpur AJ&K

32. How Does a Computer Network Work? Cables and Connectors HDMI Cables HDMI (High-Definition Multimedia Interface) cables are used to transmit high-quality audio and video signals between devices such as computers, televisions, projectors, and audio/video receivers. HDMI cables have connectors with multiple pins that carry both digital audio and video signals. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

33. How Does a Computer Network Work? Cables and Connectors USB Cables USB (Universal Serial Bus) cables are widely used for connecting peripheral devices like printers, keyboards, mice, external hard drives, and smartphones to computers. USB cables have connectors with different shapes and sizes, including USB-A, USB-B, USB-C, and micro-USB, depending on the device and the USB version. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

34. How Does a Computer Network Work? Cables and Connectors Power Cords Power cords or power cables are used to provide electrical power to devices such as computers, servers, routers, and switches. These cords typically have a plug on one end that connects to a power outlet, and a connector on the other end that attaches to the device. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

35. How Does a Computer Network Work? Cables and Connectors Patch Cables Patch cables, also known as patch cords or Ethernet cables, are short-length cables used for making direct connections between devices like computers, switches, or patch panels. They are typically used within a rack or in close proximity to connect devices to a local network Mirpur University of Science and Technology (MUST), Mirpur AJ&K

36. Wireless Access Points (WAPs) Mirpur University of Science and Technology (MUST), Mirpur AJ&K

37. Wireless Access Points (WAPs) Mirpur University of Science and Technology (MUST), Mirpur AJ&K

38. Wireless Access Points (WAPs) : Key Aspects Wireless Connectivity WAPs enable devices with wireless capabilities, such as laptops, smartphones, tablets, and IoT devices, to connect to a local area network (LAN) or wide area network (WAN) wirelessly They use radio frequency signals to transmit and receive data, allowing devices to communicate without the need for physical wired connections Mirpur University of Science and Technology (MUST), Mirpur AJ&K

39. Wireless Access Points (WAPs) : Key Aspects Network Bridging: WAPs bridge the gap between wired and wireless networks. They receive data from the wired network infrastructure, such as routers or switches, and convert it into a wireless signal that can be accessed by wireless devices. Conversely, they receive wireless signals from devices and forward them to the wired network Mirpur University of Science and Technology (MUST), Mirpur AJ&K

40. Wireless Access Points (WAPs) : Key Aspects Wireless Security WAPs play a crucial role in implementing wireless security measures. They provide encryption protocols, such as WPA2 (Wi-Fi Protected Access 2), to secure wireless communications and prevent unauthorized access. WAPs can also implement authentication mechanisms, such as Wi-Fi passwords or enterprise-level security measures like WPA2-Enterprise with 802.1X authentication. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

41. Wireless Access Points (WAPs) : Key Aspects Coverage and Range The coverage and range of a WAP depend on factors such as its transmit power, antenna design, and environmental conditions. WAPs can cover a specific area, such as a room, office, or entire building, providing wireless connectivity within their range. Multiple WAPs can be deployed to cover larger areas and ensure seamless wireless coverage throughout a location. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

42. Wireless Access Points (WAPs) : Key Aspects Management and Configuration WAPs can be managed and configured through various means. Some WAPs have a built-in web interface accessible through a web browser, allowing administrators to configure settings such as network name (SSID), security settings, channel selection, and access control. Centralized management systems or cloud-based platforms can also be used to manage multiple WAPs in a network. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

43. Wireless Access Points (WAPs) : Key Aspects Integration with Network Infrastructure WAPs are typically connected to the wired network infrastructure through Ethernet cables. They are connected to switches or routers, allowing wireless devices to communicate with devices on the wired network and access network resources such as file servers, printers, or internet connectivity. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

44. Wireless Access Points (WAPs) : Key Aspects Roaming and Seamless Connectivity When multiple WAPs are deployed within an area, they can provide seamless connectivity as users move from one WAP's coverage area to another. This allows devices to roam and maintain a stable connection without interruption, enabling mobility within the network environment. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

45. Switch Mirpur University of Science and Technology (MUST), Mirpur AJ&K

46. Switches Switches are networking devices that facilitate the connection and communication between multiple devices within a local area network (LAN) Switches are fundamental components of LANs, enabling efficient data transmission and connectivity among devices. They facilitate the creation of reliable and high-performance networks by intelligently forwarding data packets based on MAC addresses, supporting VLANs, and offering advanced features for network management and optimization. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

47. Switches : Key Aspects Device Connectivity Switches provide multiple ports that allow devices such as computers, servers, printers, and network storage devices to connect to a LAN. Each port on a switch acts as an individual connection point, allowing devices to send and receive data. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

48. Switches : Key Aspects Packet Switching Switches use packet switching to direct data packets from the source device to the destination device within a LAN When a switch receives a data packet, it examines the destination MAC (Media Access Control) address in the packet's header and forwards it only to the appropriate port where the destination device is connected This process is known as hardware-based switching or forwarding Mirpur University of Science and Technology (MUST), Mirpur AJ&K

49. Switches : Key Aspects MAC Address Learning Switches dynamically learn and maintain a table known as the MAC address table or CAM (Content Addressable Memory) table. By examining the source MAC addresses of incoming packets, switches populate the table with the MAC addresses associated with specific ports. This enables efficient forwarding of packets to the correct destination devices without flooding the entire network Mirpur University of Science and Technology (MUST), Mirpur AJ&K

50. Switches : Key Aspects Unicast, Broadcast, and Multicast Traffic Switches handle different types of network traffic Unicast traffic refers to communication between a single source and a single destination device Broadcast traffic is sent to all devices on the network, allowing communication to multiple recipients simultaneously Multicast traffic is directed to a specific group of devices that are interested in receiving the data Mirpur University of Science and Technology (MUST), Mirpur AJ&K

51. Switches : Key Aspects VLAN Support Virtual LANs (VLANs) allow network administrators to logically segment a physical LAN into multiple virtual networks. Switches with VLAN support can create separate broadcast domains, enabling network isolation, security, and improved network performance. VLANs can be configured to group devices based on specific criteria, such as department, function, or security requirements. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

52. Switches : Key Aspects Quality of Service (QoS) Switches often support Quality of Service features, which prioritize certain types of network traffic over others. QoS ensures that critical data, such as voice or video traffic, receives higher priority and consistent bandwidth, while less time-sensitive data, such as file transfers, receive lower priority. This helps maintain the desired level of service for different applications on the network Mirpur University of Science and Technology (MUST), Mirpur AJ&K

53. Switches : Key Aspects Managed vs. Unmanaged Switches Switches come in two main categories: managed and unmanaged. Unmanaged switches are plug-and-play devices that require no configuration. They are typically used in small networks and offer basic functionality. Managed switches provide advanced features and allow administrators to configure and manage the switch's settings, security, and performance parameters. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

54. Router Mirpur University of Science and Technology (MUST), Mirpur AJ&K

55. Router Mirpur University of Science and Technology (MUST), Mirpur AJ&K

56. Router : Key Aspects Interconnection of Networks Routers are used to interconnect multiple networks, such as LANs (Local Area Networks) or WANs (Wide Area Networks) They establish connections between networks, enabling devices in different networks to communicate with each other. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

57. Router : Key Aspects Packet Forwarding Routers examine the destination IP (Internet Protocol) address of incoming data packets and make decisions on how to forward them to the appropriate destination network Routers maintain a routing table that contains information about the network topology, IP addresses, and the best paths to reach specific networks Mirpur University of Science and Technology (MUST), Mirpur AJ&K

58. Router : Key Aspects Routing Protocols Routers use routing protocols to exchange information and update their routing tables Common routing protocols include OSPF (Open Shortest Path First), RIP (Routing Information Protocol), BGP (Border Gateway Protocol), and EIGRP (Enhanced Interior Gateway Routing Protocol) These protocols allow routers to dynamically discover network changes and select the most efficient paths for data transmission Mirpur University of Science and Technology (MUST), Mirpur AJ&K

59. Router : Key Aspects Network Address Translation (NAT) Routers often employ Network Address Translation to enable devices within a private network to share a single public IP address for internet access NAT translates private IP addresses to a public IP address when data leaves the private network and translates the public IP address back to the appropriate private IP address when data returns Mirpur University of Science and Technology (MUST), Mirpur AJ&K

60. Router : Key Aspects Firewall and Security Many routers include firewall capabilities to enhance network security. They can enforce access control policies, filter incoming and outgoing network traffic based on rules, and provide protection against common network threats, such as denial-of-service (DoS) attacks. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

61. Router : Key Aspects Wireless Connectivity Many routers incorporate wireless access point functionality, allowing devices with Wi-Fi capabilities to connect to the network wirelessly. These routers typically have built-in antennas and support various wireless standards such as Wi-Fi 5 (802.11ac) or Wi-Fi 6 (802.11ax). Mirpur University of Science and Technology (MUST), Mirpur AJ&K

62. Router : Key Aspects Network Segmentation Routers can segment a large network into smaller subnets, allowing for better network management, improved performance, and enhanced security. Each subnet can have its own unique IP address range and network configuration, facilitating efficient communication within the subnet and controlled access between subnets Mirpur University of Science and Technology (MUST), Mirpur AJ&K

63. Router : Key Aspects Gateway to the Internet In home or office networks, the router often serves as the gateway to the internet. It connects the local network to an internet service provider (ISP) network, enabling devices within the local network to access the internet and facilitating the exchange of data between the local network and external networks. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

64. Modem Mirpur University of Science and Technology (MUST), Mirpur AJ&K

65. Modem Mirpur University of Science and Technology (MUST), Mirpur AJ&K

66. Modem : Key Aspects Data Transmission Modems convert digital signals from computers into analog signals suitable for transmission over telephone lines, cable lines, or other communication channels. They also perform the reverse process, converting analog signals received from the communication channel back into digital signals that computers can understand. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

67. Modem : Key Aspects Internet Connectivity Modems are primarily used to establish internet connectivity. They allow computers or local networks to connect to an ISP, enabling access to the internet. The type of modem used depends on the specific technology employed by the ISP, such as dial-up, DSL (Digital Subscriber Line), cable, fiber optic, or satellite. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

68. Modem : Key Aspects Modulation and Demodulation The term "modem" comes from the functions it performs—modulation and demodulation. Modulation is the process of converting digital signals into analog signals suitable for transmission over a particular communication channel. Demodulation is the reverse process, converting analog signals back into digital signals. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

69. Model : Key Aspects Connection Types Modems come in various forms to accommodate different connection types Dial-up Modems Dial-up modems establish a connection to the ISP over a telephone line using the Public Switched Telephone Network (PSTN). They are relatively slow compared to other modem types but are less common today. DSL Modems DSL modems connect to the ISP over a DSL line, which uses existing telephone lines but allows simultaneous internet and voice communication. DSL offers faster speeds than dial-up. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

70. Modem : Key Aspects Integration with Routers In many cases, modems are integrated into routers, forming a single device known as a modem-router combo or gateway. This combination simplifies the process of connecting to the ISP and sharing the internet connection among multiple devices in a local network. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

71. Hub Mirpur University of Science and Technology (MUST), Mirpur AJ&K

72. Firewall Mirpur University of Science and Technology (MUST), Mirpur AJ&K

73. Firewall Mirpur University of Science and Technology (MUST), Mirpur AJ&K

74. Firewall : Key Aspects Traffic Filtering Firewalls analyze incoming and outgoing network traffic based on predefined rules to determine whether to allow, block, or log the data packets. They inspect packet headers, source and destination IP addresses, ports, and protocols to make filtering decisions. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

75. Firewall : Key Aspects Access Control Firewalls enforce access control policies to regulate the flow of traffic between different network segments or between internal and external networks. They can block unauthorized access attempts, such as hacking attempts or suspicious connection requests, to protect sensitive network resources Mirpur University of Science and Technology (MUST), Mirpur AJ&K

76. Firewall : Key Aspects Stateful Inspection Many modern firewalls utilize stateful packet inspection (SPI) to monitor the state of active network connections and make intelligent filtering decisions. By tracking the state of network connections, firewalls can distinguish between legitimate traffic and unauthorized or malicious activities. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

77. Firewall : Key Aspects Intrusion Detection and Prevention Advanced firewalls may incorporate intrusion detection and prevention system (IDPS) features to detect and mitigate various types of cyber threats, including malware, viruses, and denial-of-service (DoS) attacks. They can analyze network traffic patterns, signatures, and behavior anomalies to identify potential security breaches and take proactive measures to prevent them. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

78. Firewall : Key Aspects Virtual Private Network (VPN) Support Firewalls often include built-in support for VPN technologies to secure remote access connections and enable encrypted communication over untrusted networks. They can establish VPN tunnels and encrypt data traffic to ensure confidentiality and integrity, especially for remote users accessing corporate networks. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

79. Firewall : Key Aspects Logging and Reporting Firewalls maintain logs of network traffic events, security incidents, and policy violations for audit and analysis purposes. Administrators can review firewall logs, generate reports, and identify security threats or compliance issues to take appropriate actions. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

80. Firewall : Key Aspects Scalability and Performance Firewalls are available in various form factors, including hardware appliances, software applications, and cloud-based services, to suit different network architectures and performance requirements. They are designed to scale with growing network traffic and offer high throughput and low latency to minimize performance impact. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

81. Network Topology Mirpur University of Science and Technology (MUST), Mirpur AJ&K

82. Network Topology Mirpur University of Science and Technology (MUST), Mirpur AJ&K

83. Types of Network Topologies Mirpur University of Science and Technology (MUST), Mirpur AJ&K

84. Types of Network Topologies Star Topology Key Characteristics In a star topology, all devices are connected to a central hub or switch. Devices communicate with each other through the central hub, which manages data transmission. If one device fails, it does not affect the operation of other devices in the network. Features Easy to install and maintain. Scalable, as new devices can be added by connecting them to the central hub. Centralized management simplifies troubleshooting and network monitoring. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

85. Types of Network Topologies Mirpur University of Science and Technology (MUST), Mirpur AJ&K

86. Types of Network Topologies Bus Topology Key Characteristics In a bus topology, all devices are connected to a single communication line or cable. Data transmission occurs sequentially along the bus, with each device receiving the transmitted data and filtering out packets intended for it. Features Simple and inexpensive to implement. Suitable for small networks with a limited number of devices. Susceptible to network congestion and collisions, especially as the number of devices increases. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

87. Types of Network Topologies Mirpur University of Science and Technology (MUST), Mirpur AJ&K

88. Types of Network Topologies Ring Topology Key Characteristics In a ring topology, each device is connected to two neighboring devices, forming a closed loop or ring. Data packets circulate around the ring in one direction, passing through each device until they reach their destination. Each device acts as a repeater, regenerating and retransmitting data packets to maintain signal integrity. Features Balanced data traffic distribution, as each device has equal access to the network. Fault tolerance, as data can still flow in the opposite direction in case of a link failure. Difficult to reconfigure and troubleshoot, as adding or removing devices may disrupt the entire ring. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

89. Types of Network Topologies Mirpur University of Science and Technology (MUST), Mirpur AJ&K

90. Types of Network Topologies Mesh Topology Key Characteristics In a mesh topology, every device is connected to every other device in the network, forming a fully interconnected mesh of links. Data can follow multiple paths between source and destination, enhancing fault tolerance and redundancy. Partial mesh and full mesh configurations are possible, depending on the number of links between devices. Features High redundancy and fault tolerance, as multiple paths are available for data transmission. Scalable, as new devices can be added without affecting the existing network structure. Costly and complex to implement, due to the large number of required links and potential for network congestion. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

91. OSI (Open Systems Interconnection) Model Mirpur University of Science and Technology (MUST), Mirpur AJ&K

92. OSI Model Mirpur University of Science and Technology (MUST), Mirpur AJ&K

93. OSI Model Mirpur University of Science and Technology (MUST), Mirpur AJ&K

94. OSI Model Layers Physical Layer (Layer 1) The Physical Layer is responsible for transmitting raw data bits over a physical medium. It defines the electrical, mechanical, and procedural characteristics of the interface between the device and the transmission medium. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

95. OSI Model Layers Physical Layer (Layer 1) When you send a text message from your smartphone, the Physical Layer converts the digital data representing your message into electrical signals. These signals travel through the physical medium, such as copper wires or wireless radio waves, to reach the recipient's device. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

96. OSI Model Layers Data Link Layer (Layer 2) The Data Link Layer provides error detection and correction mechanisms and organizes data bits into frames for transmission over the physical layer. It ensures reliable point-to-point and point-to-multipoint communication between adjacent devices Mirpur University of Science and Technology (MUST), Mirpur AJ&K

97. OSI Model Layers Data Link Layer (Layer 2) When you connect your computer to a local network using an Ethernet cable, the Data Link Layer frames the data into Ethernet frames. Each frame contains a header with source and destination MAC addresses, ensuring that the data reaches the intended recipient within the same local network. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

98. OSI Model Layers Network Layer (Layer 3) The Network Layer is responsible for routing and forwarding data packets between different networks. It uses logical addresses (e.g., IP addresses) to determine the best path for data transmission and handles packet switching and congestion control. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

99. OSI Model Layers Network Layer (Layer 3) When you access a website on the internet, the Network Layer routes your data packets through multiple routers to reach the destination server. Each router examines the packet's destination IP address and forwards it to the next hop along the most efficient path toward its destination. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

100. OSI Model Layers Transport Layer (Layer 4) The Transport Layer ensures end-to-end data delivery by providing reliable and efficient communication services between source and destination devices. It segments and reassembles data into smaller units, adds error detection and recovery mechanisms, and manages flow control and congestion avoidance. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

101. OSI Model Layers Transport Layer (Layer 4) When you download a file from a remote server, TCP operates at the Transport Layer to establish a connection, break the file into manageable segments, ensure their delivery in sequence, and reassemble them at the destination. TCP guarantees reliable and ordered delivery of data, even over unreliable networks like the internet. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

102. OSI Model Layers Session Layer (Layer 5) The Session Layer establishes, manages, and terminates communication sessions between devices. It handles session synchronization, checkpointing, and recovery mechanisms, allowing users to establish connections and maintain ongoing interactions with network services. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

103. OSI Model Layers Session Layer (Layer 5) When you establish a remote desktop session to access a computer located elsewhere, the Session Layer manages the establishment of the session, maintains the connection state, and facilitates the exchange of data between the local and remote machines throughout the session. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

104. OSI Model Layers Presentation Layer (Layer 6) The Presentation Layer translates, encrypts, and compresses data to ensure compatibility between different systems and applications. It handles data format conversions, data encryption, and data compression to enhance the efficiency and security of data transmission. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

105. OSI Model Layers Presentation Layer (Layer 6) When you visit a secure website using HTTPS, the Presentation Layer encrypts the data exchanged between your web browser and the server using encryption algorithms like SSL/TLS. This ensures that your sensitive information, such as login credentials or credit card details, remains secure during transmission over the internet. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

106. OSI Model Layers Application Layer (Layer 7) The Application Layer provides interfaces and services for end-user applications to access network resources and services. It includes protocols and APIs that support various application-level functions, such as email, file transfer, web browsing, and remote access. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

107. OSI Model Layers Application Layer (Layer 7) When you send an email using a client application like Microsoft Outlook or Gmail, the Application Layer interacts with the user interface to compose, send, and receive email messages. It utilizes email protocols like SMTP (Simple Mail Transfer Protocol) for sending emails and POP3/IMAP for receiving emails, enabling communication between email clients and servers. Mirpur University of Science and Technology (MUST), Mirpur AJ&K

108. OSI Model : Sending an Email Mirpur University of Science and Technology (MUST), Mirpur AJ&K

109. OSI Model : Sending an Email Mirpur University of Science and Technology (MUST), Mirpur AJ&K

110. OSI Model : Accessing a Website Mirpur University of Science and Technology (MUST), Mirpur AJ&K

111. OSI Model : Accessing a Website Mirpur University of Science and Technology (MUST), Mirpur AJ&K

112. The End Questions / Discussion Mirpur University of Science and Technology (MUST), Mirpur AJ&K