Network Development PDF

 Network development What is a computer network? In a network, nodes are devices that send, receive or process data. A network links two or more nodes together t...

 Network development What is a computer network? In a network, nodes are devices that send, receive or process data. A network links two or more nodes together to Communicate and share ideas OR A computer network is a group of computers that shares information across wireless or wired technology Shared resources examples: Primary elements of a network.. Data Resources - A resource to share.. Printers Fax modem E-mail system Pathway - To transfer data (transmission medium) Protocol - A set of rules governing how computers communicate Primary benefits of a network 1. Resource sharing: Share hardware, software, and data efficiently 2. Communication: Enables email, messaging, and video conferencing, 3. Centralized management: Simplifies user control, backups, and updates. 4. Cost efficiency: Reduces equipment and maintenance costs. 5. Flexibility: Allows remote access and easy scalability. 6, Data security: Protects information with controlled access and monitoring 7. Collaboration: Enhances teamwork through shared tools and platforms. 8. Productivity: Boosts efficiency with faster access and streamlined processes. Disadvantages of networking 1. Cost: High initial costs for hardware, software, and maintenance. 2. Security risks: Vulnerability to cyberattacks, malware, and data breaches 3. Complexity: Requires technical expertise to manage and troubleshoot. 4. Dependency: Network failure can disrupt all connected systems. 5. Performance issues: Heavy traffic or poor design can cause slowdowns. 6. Privacy concerns: Shared resources and data increase the risk of unauthorized access. 7. Maintenance: Regular updates and monitoring demand time and resources. A computer operating independently from other computers is called a stand alone computer. Packet switching definition Packet Switching transmits data across digital networks by breaking it down into blocks or packets for more efficient transfer using various network devices. Each time one device sends a file to another, it breaks the file down into packets so that it can determine the most efficient route for sending the data across the network at that time. The network devices can then route the packets to the destination where the receiving device reassembles them for use.  Modems us routers Feature Modem Router What it does Connects your home to the internet Shares the Internet with all your devices Main job Translates internet signals from Creates Wi-Fi and connects your provider multiple devices Connections Connects to one device (or a router) Connects to many devices (via wi-fi or cables) IP address Gets a public IP address from your ISP Assigns local IP addresses to devices Security No built-in security Adds a firewall to protect your network Key difference.. Modem: Brings the internet to your home Router; Spreads the internet to all your devices Sometimes, one device does both jobs What is a network switch? A network switch is a device that connects devices like computers or printers in a network and helps them communicate with each other.it send data directly to the right device instead of to everyone Important definitions Servers - A server is a computer or system that provides resources, services, or data to other computers called clients over a network.it stores, manages, and shares information, like files, websites, or applications. Client - A client is a device or software that requests and uses services or resources provided by a server. Examples include a computer accessing a website or an email app retrieving messages from a mail server. Peer - A peer is a device or system that has equal status in a network and can both provide and request services or resources.in a peer-to-peer networks all devices are peers, meaning they can directly share files or resources with each other without needing a central server.  Peer-to-peer network model P2p-networks are the most basic network and is created by connecting each device together through a hub or switch. Each computer, codec, or access control panel is equal in the eyes of the switch, It is a decentralized network architecture in which participants, called peers, interact directly with each other without needing a central authority or server In a P2P network, each participant acts as both a client and a server, enabling them to share resources and services directly with other peers, Peer-to-peer network model features There is no dedicated server. Each computer is responsible for sharing its own resources. Typical environment of a few computers of lo of few computers with a maximum of 20. Security is not important. Limited growth. Client-server network model Client-server network is a network model designed for the end users called clients, to access the resources and services from a central computer known as server. The server is the central controller while all other computers in the network are called clients. A server is responsible for managing all the resources such as tiles, directories, printer, etc. Dedicated servers are faster at sharing resources. Users are not required to share resources Client-server network: pros & cons Pros: Cons: 1. Centralized control: Easy to manage 1. Cost: Expensive to set up and maintain security and resources. 2. Single point of failure: It the server goes down, 2. Better security: Easier to protect data and everything stops control access. 3. Complex setup: Needs technical knowledge to set up 3..Scalable: Can easily add more clients or and maintain. upgrade the server. 4. Server load: To many clients can slow down the server. 4. Data backup: Central storage makes data 5. Dependence: Clients need the server to easier to backup. access resources. 5. Resource sharing: Clients can access shared resources like files or databases. The difference P2P network Each mode can both request and provide services Client-server network The client modes request services and the server mode provides them  Centralized computing Centralized computing means all data and processing are done by one central server, while clients devices or users connect to it to resources or tasks Thin client-A thin client is a lightweight computer or device that relies on a central server to handle most of its processing and data storage.it has a minimal local storage and computing power, and mainly serves as an interface to access applications or services hosted on a server, Thick client- A thick client or fat client is a device that performs most of its processing and stores data locally without relying heavily on a server. Distributed computing Distributed computing is a system where processing and data are spread across multiple computers or devices, which work together to complete tasks. Each device (node) in the system contributes to the overall processing power, allowing for faster and more efficient computing. Distributed computing vs. Parael computing Distributed computing: Multiple independent computers Parallel computing: Multiple processors within Work together over a network on a task. One computer work together on a task at the same time eg., multi-core processors Advantages of P2P networks Disadvantages of P2P networks Decentralization and resilience aspect Lack of centralized control Easy scalability Network management complexity Efficient resource utilization Dependency on peer availability Cost savings Performance and efficiency variability Direct communication and faster Security risks content delivery Legal and copyright concerns Enhanced privacy and security Client-server model definition The client-server model is a way of organizing how computers communicate: a client requests services or data, and a server provides those services. Or data. For example, when you browse a website, your device (client) asks a web server for the page, and the server sends it Back to you. Steps to create a good network plan Current infrastructure Appropriate infrastructure Review the current Review the appropriate infrastructure infrastructure, if one exists requirements and/or changes. Existing technologies Documentation Review new and existing technologies Document the network design for that can be used to meet business needs historical reference  Specialised servers Application server Makes the server side of client/ server applications as well as the data available to clients. File server Provide basic networked file storage and retrieval services Print server Connect printing devices to clients on a network, accept print tasks from users & queue them-it can fail to cope with the number of requests received. Mail server Handles e-mail messages on behalf of network users, this involves acting as a cleaving house for local exchange of messages Database server A program that provides database services to other programs or computers as per client/server model. Web server. Is a computer that stores web server software and a website's component files e.g. HTML documents, images, CSS style sheets, and JavaScript files Name server A network service for resolving queries for host names to internet protocol p addresses- it translates domain names into ip addresses, Network planning and design is an iterative process encompassing topological design and network synthesis. How to design a network Key components of a server Processor Storage Write down network design requirements Choose necessary devices Ram Bandwidth Decide the type of network topology Map out network connections Create a plan for successful network design implementation, How does a server work? When a user enters a website URL in the web browser, several servers are already waiting to provide the requested information. The process begins with the web browser dividing the URL into three parts. Protocol: The first part is the hypertext transfer protocol HTTP or https, which acts as a communication pathway for servers and browsers to talk to each other. Server name: The second part of the URL relates to the server name. Here, a domain name server DNS translates the domain name into the server's IP address that hosts the requested website. File name: The final part encapsulates files that include HTML CSS, touts, images. Graphics, and many other ingredients that make up the requested website In step one, the web browser sends a domain name request to the DNS server. Next, the DNS server identifies the IP address associated with the requested domain. Upon receiving the IP address, the browser forwards the user request to the target server. The server then collects the website data along with the dynamic elements necessary to display the website on the user side and sends it back to the user as a response to the user query,  Key features of servers Scalability High processing power Reliability Cost savings Safeguard from cyberattacks Better collaboration Types of networks LAN WAN IAN HAN A local area network is A wide area network is An internet area network A home area network is a group of connected a large network that or cloud area network a small network within a computers and devices connects computers refers to a network that home that connects within a small area, like and devices over long connects devices and personal devices, such as a home school, or distances, such as systems through the computers, office,, that share between cities or internet or cloud smartphones, smart data and resources countries, often using infrastructure, allowing TVs, printers, and smart such as sprinters or the internet or other them to communicate and home devices, allowing the internet communication share resources remotely them to communicate technologies. regardless of physical and share resources like location.it relies on cloud the internet of files. services to manage and store data. SAN CAN MAN A storage area network is a high-. A campus area network is a A metropolitan area network is speed network that provides less to network that connects computers a network that covers a larger consolidated, blocklevel data storage, and devices within a limited area than a LAN, typically a city typically used by businesses or data geographic area, such as a or a large campus, it connects centers.it allows multiple servers to university campus or a business multiple LANs within the area, access shared storage devices, making campus.it is larger than a LAN but allowing for high-speed data data management more efficient and smaller than a WAN, providing high transfer and communication scalable. speed data transfer across between devices across multiple buildings or locations different buildings or locations within the campus. in a city. OSI layers OSI means open systems interconnection Application layer Application layer Presentation layer 1. Physical layer- It sends the data as bits over cables. Session layer 2. Data link layer - It organizes and checks for errors. Transport layer Transport layer 3. Network layer - It finds the best route for the data. Internet layer Network layer 4. Transport layer- It ensures data arrives in the correct order. Network access layer Data link layer 5. Session layer- It manages the communication between devices. Physical layer 6. Presentation layer - It translates and encrypts data. 7. Application layer- It's where you interact with services like email and browsing DoD layers 1, Network interface - Manages physical connections and local data delivery. 2. Internet - Routes data between networks using ip addresses. 3. Transport- Ensures reliable delivery of data. 4. Application - Provides services and interacts with the user.  Data flows through the OSI model step-by-step Application layer: Applications create the data Presentation layer: Data is formatted and encrypted. Session layer: Connections are established and managed. Transport layer: Data is broken into segments for reliable delivery. Network layer: Segments are packaged into packets and routed. Data link layer: Packets are framed and sent to the next device. Physical layer: Frames are converted into bits and transmitted physically. Sender Receiver Transmission medium UTP unshielded twisted pair is best for: 1. LANs:Used in home and office networks 2. Short distances: Effective up to 100 Meters 3. Budget-friendly: Affordable and easy to install 4. Low interference: Ideal for environments with minimal EMI Summary: UTP is great for cost-effective, simple networks in low interference settings STP shielded twisted pair is best for: 1, High-interference areas; Ideal tor environments with more electromagnetic inference, like factories or areas with heavy machinery. 2. Longer distances: Better for longer cable runs over 100 Meters compared to UTP 3. Higher security: Provides better protection from caves dropping due to its shielding. Summary: STP is great for networks in areas with high interference or for longer distances where more protection is needed. Coaxial cable is best for: 1, Cable Internet and TV: Commonly used to connect cable modems and televisions to the internet and " broadcast signals. 2. Longer distance transmission: Suitable for transmitting data over longer distances without significant signal loss. 3. High bandwidth: Capable of carrying high-frequency signals, making ii good for broadband internet and video transmission. Summary: Coaxial cable is ideal for cable TV, internet connections, and long-distance data transmission with minimal signal loss. Fiber optic cable is best for: 1. High-speed internet; Provides extremely fast data transfer speeds, ideal for high-bandwidth applications. 2.Long-distance transmission: Can carry signals over long distances without significant signal loss. 3.Low interference: Immune to electromagnetic interference, making it perfect for environments with high electrical noise. 4. Future proofing; Ideal for future-proofing networks due to its high capacity and speed. Summary: Fiber optic cables are perfect for high-speed,long distance, and interference-free data transmission.  Network topologies Network topology refers to the layout way that various elements modes, links, devices are physically and logically arranged in a computer network Bus topology It is a topology in which all the modes are connected to a single communication cable in series A bus topology is used in: 1, Small networks: Simple and cheap for small offices or homes. 2. Temporary networks: Quick setups like conferences. 3. Limited budget: Cost-effective for schools or startups. 4. Legacy systems: Older setups that can't upgrade easily. Advantages: Easy, low-cost setup. Disadvantages: Not good for large networks; a single cable failure affects the whole network. Star topology It is a topology for a local area network in which all modes are individually connected to a central connection point, like a hub or switch. A star topology is used in: 1. Modern networks: Common in homes, offices, and businesses. 2. High reliability: Each device connects to a central hub so it one connection fails, others aren't affected. 3. Easy troubleshooting:Issues are easier to identify and fix since each device is connected separately. 4. Scalability: Adding or removing devices is simple. Advantages: Reliable, easy to manage and scalable. Disadvantages:If the central hub fails, the entire network goes down, and it can be more expensive due to extra cabling. Ring topology It is a network configuration in which device connections create a circular data path. Each networked device is connected to two others, like points on a circle. A ring topology is used in: 1. Small to medium networks: Suitable for networks where data needs to travel in a specific order. 2. Data flow control: Each device is connected to two others, forming a ring, which helps manage data traffic efficiently. 3. Token passing:Often used in networks where a "token" is passed around to control which device can send data, reducing collisions. Advantages: Organized data flow, good for handling high traffic. Disadvantages: If one device or connection fails, it can affect the entire network, and troubleshooting can be harder. DHCP DHCP dynamic host configuration protocol automatically assigns ip addresses to devices on a network. Here's how it works; 1. Discovery:The device requests an IP. 2. Offer: The DHCP server offers an IP. 3. Request: The device accepts the offer. 4. Acknowledgment:The server confirms the lease, and the device uses the IP. Summary: DHCP makes it easy to connect devices by automatically assigning and managing IP addresses. IP addressing IP addressing definition An IP address is a 32 -Bit number than uniquely identifies a host like a computer or other devices such As a printer or Or router on a TCP/IP network The main purpose of IP addressing To identify devices on a network Ensue that data sent from one device reaches the correct destination Subnet mask definition Defines the network and host portions of the IP address.it determines which part of the IP address is the network identifier and which part is the host identifier. DNS DNS domain name system translates domain names like www.example.com into IP addresses. How it works: 1. Query: Your device asks a DNS server for the IP address of a website. 2. Lookup: The DNS server finds the IP address, either from its records or By asking other servers. 3. Response: The server sends the IP address to your device. 4. Connection: Your device uses the IP to connect to the website. Summary: DNS works like a phonebook, converting website names into IP addresses.