_Computer_Networking_Guide__1743168051.pdf
- 1. Computer Network C R E AT E D B Y : - M I T H U R S H A N ( H N D I T, N D I T ) CNT
- 2. What is a Computer Network? 2 A computer network is a group of computers or computer like devices connected together to share the network resources like files, printers, network services etc. Computer networks are required for network communication and network resource sharing (printers, scanners, storage spaces etc.). To build and connect computer networks, we need computers (Clients and Servers) and special network infrastructure devices.
- 3. Benefits of a computer network. 3 1. File sharing: Networking of computers helps the network users to share data files. 2. Hardware sharing: Users can share devices such as printers, scanners, CD-ROM drives, hard drives etc. Without computer networks, device sharing is not possible. 3. Application sharing: Applications can be shared over the network, and this allows to implement client/server applications
- 4. Benefits of a computer network continue… 4 4. User communication: Networks allow users to communicate using e-mail, newsgroups, and video conferencing etc. 5. Network gaming: A lot of network games are available, which allow multi-users to play from different locations. 6. Voice over IP (VoIP): Voice over Internet Protocol (IP) is a revolutionary change in telecommunication which allows to send telephone calls (voice data) using standard Internet Protocol (IP) rather than by traditional PSTN(public switched telephone network).
- 5. Client Operating Systems (Workstation Operating Systems) and Network Operating Systems - NOS (Server Operating Systems) 5 What is a Client Computer? • A client refers to a computer in your network. • A network user performs activities on this client computer. •Examples of network activities: Downloading a file from a File Server. •Browsing the Intranet or Internet. • The client computer is used for the user's daily tasks.
- 6. Client Operating Systems (Workstation Operating Systems) and Network Operating Systems - NOS (Server Operating Systems) 6 What is a Server Computer? • A client computer connects to a server to access services installed on it. • Servers are not meant for browsing the internet or doing tasks like spreadsheets. • Servers run a specialized Operating System (OS) and software to serve network clients continuously.
- 7. Network Operating Systems - NOS (Server Operating Systems) 7 Server Operating System (Network Operating System - NOS): • Servers offer services to network client devices. • Server machines run on a specialized OS with more features and processing capabilities than client OS. • Typically has more computing resources than client computers: • More processors and processing power. • More physical memory (RAM). • More storage space.
- 8. Network Operating Systems - NOS (Server Operating Systems) Continue.. 8 Examples of Server Operating Systems: • Windows Server: • Windows NT (obsolete). • Windows 2000 (obsolete). • Windows 2003 (legacy). • Windows 2008 / Windows 2008 R2 (legacy). • Windows 2012 / Windows 2012 R2 (legacy). • Windows 2016 (current). • Windows 2019 (current). • Windows 2022 (latest). • Unix-based: • Oracle Solaris. • IBM AIX. • HP-UX. • FreeBSD. • NetBSD. • OpenBSD. • SCO Unix. • Illumos (Open-source Unix-based OS derived from Solaris) • ZFS on Linux (ZoL) (Popular filesystem integrated with Unix-based systems).
- 9. Network Operating Systems - NOS (Server Operating Systems) Continue.. 9 Examples of Server Operating Systems: •GNU/Linux: •RedHat Enterprise Linux (RHEL). •Debian Linux. •SUSE Enterprise. •Ubuntu Server. •CentOS Server (discontinued, replaced by CentOS Stream). •Mandriva. •Fedora. •Latest: • AlmaLinux (CentOS alternative). • Rocky Linux (CentOS alternative). • OpenSUSE. • Arch Linux.
- 10. Client Operating Systems (Workstation Operating Systems, or Desktop Operating Systems) 10 • The basic functions of an operating system are: • Booting the computer • Performs basic computer tasks • e.g. managing the various peripheral devices e.g. mouse, keyboard • Provides a user interface, • e.g. command line, graphical user interface (GUI) • Handles system resources such as computer's memory and sharing of the central processing unit (CPU) time by various applications or peripheral devices • Provides file management which refers to the way that the operating system manipulates, stores, retrieves and saves data.
- 11. Client Operating Systems (Workstation Operating Systems, or Desktop Operating Systems) Continue.. 11 • Windows 95/98/ME and Vista (obsolete). • Windows NT Workstation / Windows 2000 Professional (obsolete). • Windows XP (legacy). • Windows 7 (legacy). • Windows 8 / Windows 8.1 (current). • Windows 10 (current). • Windows 11 (current). • GNU/Linux Desktops: •RedHat Enterprise Linux Desktop. •SUSE Desktop. •Ubuntu Desktop. •LinuxMint. •Latest: • Pop!_OS. • Elementary OS. • Manjaro Linux. • Most Popular Client Workstation Operating Systems:
- 12. Common Network Application Software 12 • A network application that allows users to access the internet. • Interprets HTML (HyperText Markup Language) files sent from a web server and displays content on the screen. • The most widely used network application. Most Widely Used Web Browsers: Mozilla Firefox Microsoft Internet Explorer Google Chrome Opera Apple Safari • Web Browser:
- 13. Common Network Application Software Continue …. 13 • E-mail (Electronic Mail) Applications are used for composing and sending e-mails within the same network or to outside the network. Most widely used E-mail (Electronic Mail) Applications products are Mozilla Thunderbird Microsoft Outlook Evolution Gmail (web-based) • E-mail Applications:
- 14. Local Area Network (LAN), and Wide Area Network (WAN) 14 • Local Area Network (LAN): Local Area Network (LAN) is a computer network, which is limited to a small office, single building, multiple buildings inside a campus etc. Typically a Local Area Network (LAN) is a private network owned and maintained by a single organization.
- 15. Local Area Network (LAN), and Wide Area Network (WAN) 15 Wide Area Network (WAN): • Spans(பரவியுள்ளது) multiple geographic locations. • Composed of multiple Local Area Networks (LANs). • Typically impractical for small to medium organizations to directly connect offices in distant locations. • Network Service Providers (ISPs) offer connectivity solutions for WANs. • Example: • Two LANs located in different geographic locations • LAN 1: Chennai, India.. • LAN 2: Manila, Philippines. • Aerial distance between Chennai and Manila: approximately 4,400 kilometers. • WAN link between the two LANs is typically established through the services of an ISP.
- 16. Local Area Network (LAN), and Wide Area Network (WAN) 16 Wide Area Network (WAN):
- 17. Differences between Local Area Networks (LANs) and Wide Area Network (WAN) 17 Geographic Scope: • LAN: Connects computers in small physical areas (e.g., small office, single building, multiple buildings in a campus). • WAN: Connects offices in different geographical locations, often relying on ISPs for connection solutions. Bandwidth: • LAN: Higher bandwidth (100 Mbps, 1 Gbps, 10 Gbps). • WAN: Lower bandwidth (4 Mbps, 8 Mbps, 20 Mbps, 50 Mbps, 100 Mbps). Bandwidth Consistency: • LAN: Bandwidth rates are almost constant(நிரந்தரமான/ மாறாத), depending on LAN technology (Fast Ethernet or Gigabit Ethernet). • WAN: Bandwidth depends on ISP services and may vary due to budget constraints. Technologies Used:: • LAN: Typically uses Ethernet standards (Fast Ethernet 100 Mbps, Gigabit Ethernet 1/10 Gbps). • WAN: Uses technologies like VPN over Internet, MPLS, Frame Relay, or Leased Lines.
- 18. Differences between Local Area Networks (LANs) and Wide Area Network (WAN) 18 Security and Reliability: • LAN: More reliable and secure, managed by dedicated local administrators. • WAN: Less reliable and secure, as it involves third-party ISPs Initial Setup Costs: • LAN: Low setup costs, as devices are cheaper. • WAN: High setup costs due to expensive devices (routers, firewalls), cables, and manpower. Running Costs: • LAN: Lower running costs. • WAN: Higher running costs, often with recurring monthly service provider fees.
- 19. CAN and MAN, Campus Area Network (CAN) and Metropolitan Area Network (MAN) 19 Campus Area Network (CAN): • Larger version of Local Area Network (LAN). • Consists of multiple LANs connected across a large campus. • Examples: University, business park, or hospital spanning over hundreds of acres(Vf;fu;). Metropolitan Area Network (MAN): • Larger than CAN but smaller than Wide Area Network (WAN). • Interconnects multiple LANs within a city using high-bandwidth backbone links.
- 20. SAN, PAN, TAN and HAN 20 Storage Area Network (SAN): • Attaches remote computer storage devices to servers. • Appears as locally attached to the operating system. Personal Area Network (PAN): • Used for communication among devices (phones, PDAs, fax machines, printers) near a single user. Tiny Area Network (TAN): • Small LAN with a few nodes, usually in homes or small offices • Devices share resources like modems, files, or printers. Home Area Network (HAN): • Network within a home connecting digital devices (computers, phones, TVs, security systems, appliances).
- 21. Peer-to-Peer networks and Client-Server networks 21 Peer-to-Peer networks • No dedicated servers; all workstations are equal. • Workstations (or clients) connect to share devices, information, or data. • Any computer can act as a client or server at any time. • Ideal for small networks, such as home networks, small business networks, or retail shops. • Microsoft's term for Peer-to-Peer network: "Workgroup.“ • No strict limit on the number of computers, but typically less than 10 workstations.
- 22. Peer-to-Peer networks and Client-Server networks Continue… 22 Disadvantages of Peer-to-Peer Networks: • Data is distributed across different computers. • User-generated files are stored on individual computers, making data backup difficult. • No centralized user database; each computer has its own user and privilege management. • Users must remember their IDs and passwords for every computer, making user management challenging
- 23. Peer-to-Peer networks and Client-Server networks Continue… 23 Client-Server Networks: Client: • A computer seeking resources from another computer. • Used by network users for activities like downloading files or browsing the intranet/internet. • The client performs day-to-day work tasks. Server: • A computer providing resources to other computers • Client connects to the server to access services. • Not meant for tasks like browsing the internet or spreadsheet work. • Installed with an appropriate OS and software to serve network clients continuously.
- 24. Peer-to-Peer networks and Client-Server networks Continue… 24 Client-Server Networks: Requirements: • Dedicated servers are required. • Server hardware is more expensive than desktop computers. • Client-server networks cost more than peer-to-peer networks. • Network Operating Systems (NOS) are costlier than desktop operating systems.
- 25. Peer-to-Peer networks and Client-Server networks Continue… 25 Different types of Servers used in networks are listed below. File Server: • Stores user documents and files centrally. • Requires large memory, storage, fast hard disks, multiple processors, fast network adapters, redundant power supplies. • Advantage: Easy management and backup of user files and documents. Print Server: • Redirects print jobs from client computers to specific printers. Mail Server: • Transmits emails using protocols like SMTP (Simple Mail Transfer Protocol). • Exchanges emails between different domains.
- 26. Peer-to-Peer networks and Client-Server networks Continue… 26 Different types of Servers used in networks are listed below. Application Server: • Runs common applications or programs centrally. • Allows multiple users to access shared applications over the network. Database Server: • Allows authorized clients to create, view, modify, and delete data stored in a common database. Directory Server: • Central administration and management of users and resources. • Provides network security features: Authentication, Authorization, and Accounting (AAA).
- 27. Internetworks, Internet, Intranet and Extranet continue .. 27 Internetwork: • Defined as two or more connected computer networks (typically Local Area Networks - LANs). • Uses Network Routers to connect different networks. • Each network in an internetwork has its own unique network address. • Network address identifies individual networks within the internetwork. • Allows users in different geographical locations to share data, resources, and communicate. • Essential for modern business operations. Types of Internetworks: • Internet • Intranet • Extranet
- 28. Internetworks, Internet, Intranet and Extranet continue .. 28 Internet: • A global, publicly accessible network of interconnected computer networks. • Transmits data using Internet Protocol (IP). • World's largest internetwork. • World Wide Web (WWW): Not the same as the Internet. • Internet is a collection of networks; WWW is a collection of interconnected documents and resources. • WWW is accessed via hyperlinks and URLs. • Other services accessible via the Internet include: • Email • File sharing • Remote administration • Video streaming • Online gaming
- 29. Internetworks, Internet, Intranet and Extranet continue .. 29 Intranet: • A private network within an enterprise. • May include many interlinked LANs and use WAN technologies for connectivity. • Purpose is to share company information and computing resources among employees. • Content is restricted to organization members (usually employees). Extranet: • A private network that uses Internet technology for secure sharing. • Shares business information with suppliers, vendors, partners, customers, or other businesses. • Considered part of a company's intranet but extended to external users.
- 30. Topology 30 Definition: Network topology refers to the physical layout of computers, cables, and other components in a network. There are various network topologies, and a network may incorporate multiple types. Common types include: • Bus Topology • Star Topology • Mesh Topology • Ring Topology • Hybrid Topology • Wireless Topology
- 31. Bus Topology 31 Description: A bus topology is a network setup where all devices (e.g., workstations, printers, servers) are connected to a single, linear cable with terminators at each end. These terminators absorb signals to prevent signal bounce, which could cause network issues
- 32. Bus Topology Continue … 32 Advantages of Bus Topology: Easy to connect a computer or peripheral to a linear bus. Requires less cable length than a star topology. DisAdvantages of Bus Topology: Entire network shuts down if there is a break in the main cable. Terminators are required at both ends of the backbone cable. Difficult to identify the problem if the entire network shuts down.
- 33. Star Topology 33 Description: A star topology is designed with each node (like workstations, printers, laptops, servers etc.) connected directly to a central device called as a network switch. Each workstation has a cable that goes from its network card to a network switch. • Most popular and widely used LAN technology Ethernet currently operates in Star Topology.
- 34. Star Topology Continue … 34 Advantages of Star Topology • Easy to install and wire. • No disruptions to the network when connecting or removing devices. • Easy to detect faults and to remove parts. Disadvantages of Star Topology • Requires more cable length than a linear bus topology. • If the connecting network device (network switch) fails, nodes attached are disabled and cannot participate in network communication. • More expensive than linear bus topology because of the cost of the connecting devices (network switches).
- 35. Mesh Topology 35 Definition: • Every network device is connected to all other devices in the network.
- 36. Mesh Topology Continue … 36 Advantages of Star Topology • Provides multiple paths to the destination. • If one link fails, another path is available. • Ensures redundancy and reliability, especially in wireless networks. Disadvantages of Star Topology • Expensive due to the need for extra cables. • Difficult to manage because of its complexity. Usage • Not commonly used in wired networks due to cost and complexity. • Often used in wireless networks. Types of Mesh Topology: • Full Mesh • Partial Mesh
- 37. Ring Topology 37 Definition: • All computers are connected in a loop or circle with no start or end. • No terminators are needed.
- 38. Ring Topology Continue … 38 Advantages of Star Topology • Low signal degeneration as each device regenerates the signal. Disadvantages of Star Topology • If one workstation fails, the entire network fails. Signal Transmission • Signals travel in one direction, passing from one computer to the next. • Each computer regenerates the signal to maintain signal strength over long distances.
- 39. Hybrid Topology 39 Definition: • Hybrid topology is a mixture of different topologies. Example is star-bus topology.
- 40. WAN (Wide Area Network) Topologies 40 What is a Wide Area Network (WAN)? • A WAN connects multiple networks over large geographical areas. • Example: Connecting a Main Office (Head Office) to Branch Offices. • Data flows through different environments. • Main Office (Head Office) • Remote Locations (Branch Offices, Home Users, Travelling Employees)
- 41. WAN (Wide Area Network) Topologies… 41 Office (Head Office): • Central hub where branch offices report. • Location of top departmental heads. • Hosts key enterprise servers. • Branch office networks connect to the Main Office.
- 42. Remote Locations in WAN 42 Branch Offices: • Located remotely and connected via WAN. • Fewer users and resources than the Main Office. • Hosts less critical servers. Home Users: • Employees working from home. • Connected using a VPN over broadband internet.
- 43. Remote Locations in WAN 43 Travelling Employees: • Managers, sales, or technical staff working remotely. • Use VPN-protected internet for secure connection.
- 44. Thank you C R E AT E D B Y : - A . M I T H U R S H A N ( H N D I T, N D I T )