communication and networking parallel and distributed computing

its a slides

1. Introduction to Computer Network Week 01

2. Outline Overview of Computer Networks Network Protocols OSI and TCP/IP Model Role of Protocols in Networks

3. Scope Networks support the way we learn . Networks support the way we communicate. Networks support the way we work. Networks support the way we play. Networking is Everywhere

4. Computer Network A computer network is a set of nodes connected by COMMUNICATION LINKS .

5. Computer Network A computer network is a set of nodes connected by COMMUNICATION LINKS .

6. Node? A NODE can be a computer, printer or any other device capable of sending/receiving data generated by other nodes in the network. printer server security camera Capable of sending/receiving data computer switches Any other device

7. Nodes Examples of NODE Computer Server Printer Security camera Other devices (Switches, Bridges, Routers etc.)

8. Computer Network A computer network is a set of nodes connected by COMMUNICATION LINKS .

9. COMMUNICATION LINK A link is a communication channel that connects two or more devices  for the purpose of data transmission.

10. Wireless link Wired link COMMUNICATION LINKS A Communication link can be a wired link or wireless link The link carries the information

11. links Links (medium) Wired: Cable Wireless: Air

12. Example of computer network Resource sharing

13. Example of Computer network

14. Activity time Find out the end nodes (end devices) and intermediary nodes depicted in the scenario and place them rightly. END DEVICES INTERMEDIATE NODES

15. Activity time Find out the end nodes (end devices) and intermediary nodes depicted in the scenario and place them rightly. END DEVICES INTERMEDIATE NODES PC Router Printer Wireless Server Cell tower Tablet Modem Smart phone Internet cloud

16. Characteristics of Computer Network we are going to discuss some basic characteristics of Computer Networks.

17. Basic characteristics of computer network Fault tolerance Scalability Quality of service (QoS) security

18. Fault tolerance Its the ability to Continue working despite of failure Ensure no loss of service

19. Fault tolerance Fault tolerance in computer networks is like having a backup plan for when things go wrong. It's all about designing a network that can keep running smoothly even if some parts of it fail

20. Fault tolerance - network Why is it Important? In today's interconnected world, network downtime can have serious consequences. It can lead to:   Loss of productivity: If a business network goes down, employees can't access critical systems and data, leading to lost time and revenue.   Disruption of services: Network outages can interrupt essential services like healthcare, transportation, and emergency response. Damage to reputation: Frequent network failures can erode trust and damage an organization's reputation

21. Fault tolerance

22. SCALABILITY What is Network Scalability? Network scalability refers to the ability of a network or system to handle a growing amount of change and its potential to be enlarged to accommodate that growth.

23. Scalability Its the ability to Grow based on the needs Have good performance after growth

24. Scalable network – the internet

25. Security is protection from, or resilience against, potential harm (or other unwanted coercion). It is the practice of protecting a network from unauthorized access, misuse, or attacks. It involves using tools, technologies, and policies to keep data safe.  SECURITY

26. Security The ability to prevent Unauthorized access Misuse Forgery the ability to provide Confidence Integrity availability

27. Security

28. Q o S A set of technologies that manage network traffic by prioritizing specific data flows, ensuring that critical applications receive the necessary bandwidth and performance even under limited network capacity, effectively guaranteeing a certain level of service for high-priority applications and users

29. Quality of service (Q O S) The ability to Set priorities Manage data traffic to reduce data loss , delay etc .

30. Prioritization: QoS allows network administrators to assign different priority levels to various types of traffic, like voice calls, video streaming, and regular data transfer, ensuring that essential applications receive preferential treatment.  Traffic management techniques: Mechanisms like queuing, classification, policing, and marking are used to manage data flow and prioritize specific traffic types.  Performance metrics: QoS is measured by factors such as packet loss, latency, jitter, and throughput, which are used to assess the overall quality of network service.  Application scenarios: QoS is particularly important for applications that require real-time performance, such as video conferencing, online gaming, and telephony, where consistent low latency and minimal packet loss are crucial.  Key points of Q O S

31. Data communication Data flow and Protocols

32. Data communication Data communications are the exchange of data between two nodes via some form of link (transmission medium) such as a cable.

33. Transmission Modes Transmission modes define the direction of data transmission, it defines the direction of the flow of information between two communication devices. Every data transmitted on the communication channel has a direction and this direction between two communication devices is defined by data transmission modes. Also referred to as Data Communication mode or Directional mode. Three types of Transmission mode Simplex Mode Half-Duplex Mode Full-Duplex Mode

34. Data flow Data Flow (Transmission mode) Full-Duplex Half-Duplex Simplex Duplex

35. Data flow - simplex Communication is always unidirectional One deceive can transmit and other deceive will receive examples

36. Simplex In simplex mode, data can flow in only one direction, Unidirectional. In this mode, a sender can only send data but cant receive it similarly, a receiver can only receive data but cant send it. It’s a one-way communication mode as it allows data to flow in only one direction, the sender cannot receive any feedback or acknowledgment from receiver. Simplex mode is mostly used for broadcast communication, where one device sends a message to multiple recipients, but the recipients cannot respond or send data back. Examples : television broadcast transmitting a TV program to multiple viewers, a radio station transmitting music to listeners.

37. Simplex Advantages: Simplex mode requires fewer resources, like bandwidth and processing power Simple to implement and does not requires complex synchronization between sender and receiver. Disadvantages: No Feedback Limited Functionality Inefficient for two-way communication.

38. Data flow – half duplex Communication is in both directions but not the same time If one device is sending, the other can only receive, and vise versa. Example : walkie talkie

39. Data flow – Half-Duplex In half-duplex mode, data can flow in both directions but in one direction at a time Means when one node is sending the data, then the receiving node has to wait. While one device is sending the other can only receive and vise versa Transmitter/ Receiver Transmitter/ Receiver Half-Duplex (Takes Turns)

40. Half-Duplex Advantages: Its simpler to implement compared to full-duplex mode, as it does not require complex synchronization between the sender and receiver. It requires a smaller bandwidth compared to full-duplex mode. Disadvantages: Lack of simultaneous communication between the sender and the receiver can limit the functionality of the communication system. Less efficient compared to full-duplex mode Need for a turn-taking mechanism can add overhead and latency to the communication system.

41. Data flow – Duplex/Full-Duplex Communication is in both directions simultaneously Device can send and receive at the same time Example: telephone line

42. Data flow – Duplex/Full-Duplex Full-Duplex mode in computer networks is a type of data transmission in which data can be transmitted in both directions simultaneously. This means that two device can send and receive data at the same time, without any delay or waiting time. Full-Duplex mode is often used in local area networks (LANs), where multiple devices need to communicate with each other simultaneously. In this system, each device has a dedication communication channel for sending and receiving data. This allows for high-speed, high-bandwidth communication between devices. Transmitter/ Receiver Transmitter/ Receiver Full-Duplex (transmit simultaneously)

43. Full-Duplex Advantages: It allows data to be transmitted in both directions simultaneously, which increases the efficiency and performance of the communication system. Its supports high-speed, high-bandwidth communication, making it suitable for applications that require large amounts of data to be transmitted quickly. It eliminated the need for devices to take turns transmitting data, reducing the latency in the communication system. Disadvantages: Need more complex hardware and software, which increase the cost of the communication system. Requires a larger bandwidth Increases the risk of collisions, where two devices transmit data at the same time and data is lost.

44. Protocols Computer Network Protocols

45. Protocols Protocols = rules. It is the set of rules that govern data communication Protocol determines: What is communicated? How it is communicated? When it is communicated?

46. If there are no protocols….

47. Protocols All communication schemes will have the following things in common: Source or sender Destination or receiver Channel or media Rules or protocols govern all methods of communication

48. Protocols – Human Communications Protocols are necessary for human communication and include: An identified sender and receiver Common language and grammar Speed and timing of delivery Confirmation or acknowledgement requirements

49. Network Protocols Network protocols are a set of rules outlining how connected devices communicate across a network to exchange information easily and safely. Protocols serve as a common language for devices to enable communication irrespective of differences in software, hardware, or internal processes.

50. Protocols – network communication Protocols used in network communication also define: Message encoding Message formatting and encapsulation Message timing Message size Message delivery options

51. Elements of a protocol Message encoding Message formatting and encapsulation Message timing Message size Message delivery options

52. 1. Message encoding Message Source Encoder (Signal) Transmitter Transmission Medium Receiver Decoder (Signal) Message destination

53. 2. Message formatting and encapsulation T he process of structuring a message with a specific format, including headers containing relevant information like source and destination addresses, and then "wrapping" that data within additional layers of information to prepare it for transmission across a network Agreed format. Encapsulate the information to identify the sender and the receiver rightly.

54. 3. Message size Message size refers to the total amount of data contained within a single message being transmitted, including the message header, body, and any attached files, essentially defining the overall weight of the information being sent across a network or communication channel; it is often measured in bytes or kilobytes Long messages must also be broken into smaller pieces to travel across a network.

55. 4. Message timing Message timing refers to the precise moment a message is sent and received, essentially dictating the speed at which data is transmitted across a network, ensuring proper synchronization between devices and preventing data loss by managing when and how much data can be sent at any given time. Manages Flow control Response timeout

56. 5. Message delivery options The different methods available to send data (messages) across a network, including choices like unicast (one-to-one), multicast (one-to-many), and broadcast (one-to-all), allowing you to specify whether a message should be delivered to a single recipient, a specific group of recipients, or all devices on the network, respectively Options: UNICAST MULTICAST BROADCAST

57. UNICAST

58. Multicast

59. Broadcast

60. OSI and TCP/IP Model Network protocols

61. OSI and TCP/IP Model A network protocol is a set of rules that govern how data is transmitted and received across a network, while the OSI (Open Systems Interconnection) model and TCP/IP model are conceptual frameworks that divide network communication functions into distinct layers, providing a structured way to understand how data flows through a network. These models work as frameworks for organizing and understanding how data moves from one device to another across networks.

62. OSI Model OSI stands for Open Systems Interconnection. It has 7 layers. Each layer performs its task independently. It was developed in 1984 by the International Organization for Standardization (ISO).

63. TCP/IP Model TCP/IP stands for Transmission Control Protocol/Internet Protocol. It has 4 layers. It also can be used as a communications protocol in a private computer network. It was designed by Vint Cerf and Bob Kahn in the 1970s.

64. Role of Protocols in Network Network protocols play a vital role in network design and operation, as they define the rules and standards for communication, and impact network performance, security, and interoperability. Network designers must choose the appropriate protocols for each type of communication, taking into account the trade-off between reliability and speed, security, and interoperability. By understanding the role of network protocols in network design, network administrators can ensure that their networks operate effectively and efficiently.

65. "Computer networks: Weaving a digital tapestry that connects minds, bridges distances, and empowers the world." I hope this has given you a good foundation in [topic]. I encourage you to explore this further.