Networks Overview - Turbolearn AI

Created by Turbolearn AI Networks Overview The concept of networks revolves around the interaction between a server and a client. A client requests services or connects to a server within the same network. A server is a centralized system holding data and managing instructions. Thi...

Created by Turbolearn AI Networks Overview The concept of networks revolves around the interaction between a server and a client. A client requests services or connects to a server within the same network. A server is a centralized system holding data and managing instructions. Think of a bar: clients customers order drinks from the server bartender, who handles the requests. Computer Networks A computer network consists of multiple computers connected to each other, capable of sending and receiving data. This can be to a centralized system or in a peer-to-peer manner. Hub, Switch, and Router There are different ways to connect computer systems: Hub: Sends data to all devices on the network, regardless of the intended recipient. Switch: Sends data from one specific computer to another on the network. Router: Connects multiple networks, allowing them to communicate e. g. , ahomeW i − F inetworkconnectingtotheinternet. The Internet The internet is a vast network utilizing the TCP/IP protocol for data transmission. It lacks a central governing body. The internet refers to the physical infrastructure wires, mobilenetworks, etc.. The World Wide Web W W W is the collection of information, like websites and web pages, accessible via the internet. ISPs I nternetServiceP roviders manage networks, granting users internet access through internet exchanges. Internet exchanges are crucial for the internet's global functionality, linking different ISPs together. These exchanges are usually managed by academic institutions or non-profits. Data Transmission The internet transmits data through packets. A single piece of data, like a picture, is divided into numerous packets, which may travel different routes but ultimately reach the same destination where they are reassembled. This process is known as packet switching. A packet is a unit of information. Data Packet Structure A data packet typically includes: Payload: The actual data e. g. , image, textf ile, etc. in binary format. Header: Contains sender and destination information. Trailer: Contains information such as error checking data. Routers Routers manage traffic, control data packet flow, and ensure packets reach their intended destination efficiently. Routers act as relays on the internet, guiding packets. Page 1  Created by Turbolearn AI Types of Networks Networks can be configured differently for various purposes. Local Area Network LAN A local area network LAN typically covers a single building with a radius of one kilometer or less e. g. , ahomenetwork, aschoolnetwork. Wide Area Network W AN A wide area network W AN covers a much larger area than a LAN, potentially connecting multiple LANs via routers. Examples of WANs: The internet. Cellular networks. ATM networks. Network Types LAN vs. WAN Local Area Network LAN vs. Wide Area Network W AN : The primary difference is geography. LANs cover smaller areas e. g. , abuilding. WANs cover larger areas. Data Transfer Rate: LANs usually have higher data transfer rates due to shorter distances, which reduces signal dilution. Cost: WANs are generally more expensive due to the infrastructure wires, etc. required to connect networks over a wider area. Technical Problems: WANs tend to have more technical issues because of the multiple devices and routers involved. Virtual Networks Virtual Local Area Network V LAN VLAN: An artificial network created using network switches or software configuration that mimics a physical LAN. Allows for more networks from a software perspective than physically available. Used to group computers into virtual networks with different access and security requirements. Flexibility: Easier to switch computers between networks via software configuration. Security: Different security settings can be implemented for each VLAN more efficiently than with a physical LAN. Complexity: May require custom software configuration or specific switchboard setups. Use Case: Beneficial for larger organizations to reduce the need for multiple physical LANs. Storage Area Network SAN SAN: A dedicated network of storage devices. May appear as shared drives on a school network. Computers access the SAN directly, bypassing typical LAN or Wi-Fi networks. Stores various data types like emails, application data, and database data. Typically includes backup servers and batteries for fault tolerance and data conservation. Offers better performance because servers are dedicated to data storage. Access: Computers directly access the SAN through a router or switchboard. Wireless Networks Page 2  Created by Turbolearn AI Wireless LAN W LAN WLAN: A LAN where devices connect wirelessly via radio waves W i − F i. Wi-Fi is a type of radio wave used for wireless connections. Functionality: Devices make requests to a Wi-Fi router, which then communicates with the Internet. Licensing: No need to license the radio spectrum. Mobility: No cables, allowing for movement within the network's range. Global Standards: Devices can connect to Wi-Fi networks globally. Ease of Setup: Relatively simple to set up. Interference: Susceptible to interference from objects like refrigerators. Range: Limited coverage area. Security: Vulnerable to hacking if not properly secured. Health Concerns: Some unverified health concerns associated with wireless technology. Personal Area Network P AN PAN: Connects devices in a user's immediate vicinity. Similar to a LAN but with a smaller radius. Examples: Wi-Fi hotspots and Bluetooth devices. Connecting devices like AirPods to a laptop via Bluetooth creates a PAN. Private Networks Intranet and Extranet Intranet: A private internet accessible only within a specific network. Uses TCP/IP and web pages but is isolated from the World Wide Web. Example: A company's internal discussion board accessible only when connected to the company's Wi-Fi. Example: North Korea's internet system, which is a closed network. Extranet: An intranet that can be accessed through an online portal. An intranet becomes an extranet when it allows access to external users through a portal. Virtual Private Networks V P N s VPNs are a common way to securely access servers and information. When you use a VPN client likeN ordV P N , you're accessing a VPN server hosted by the company that owns the client. Your device (the user) sends information through an encrypted tunnel to a VPN server. The VPN server then sends the request to the destination e. g. , google. com. The response from the destination is sent back to the VPN server, which forwards it to you through the encrypted tunnel. The VPN server acts as an intermediary, so the destination only sees the VPN server's IP address, not your actual IP address. Tunneling: The process of creating and maintaining an encrypted connection between a server and a client. Technologies like SSL, TLS, or IPSec are used for encryption. Advantages of VPNs: Page 3  Created by Turbolearn AI Advantage Description You have control over what information you send and what encryption is used. You must log in to the VPN Authentication client to use it. Encryption No one can see the data you're sending through the VPN. Tunneling Data is heavily secured between you and the VPN server. Multiple Exit Provides anonymity, as websites cannot directly identify you or your location unless you explicitly provide Nodes identifying information. They only see the VPN server's IP address. Peer-to-Peer P 2P Networks In a peer-to-peer network, computers share resources directly with each other, without a centralized server. Each computer acts as both a client and a server. There is no central point through which all data passes. Each computer has a direct connection with every other computer in the network. A real-world example of a P2P network is speed dating, where individuals communicate directly with each other without an intermediary. This is in contrast to a dating website, where communication is centralized through the website's platform. > Client-Server Model: A model where multiple clients access a centralized server for information and resources. T hinkairportkiosksgoingtoacentralcomputer Protocols Protocols: The rules for data transmission in a network. In the internet, the TCP/IP protocol is commonly used. HTTPS is used for transmitting data between a web browser and a server. SFTP is used for transferring files from a client to a server. Protocols have a few basic functions: Data Integrity: Ensuring that the data sent is the same as the data received. Flow Control: Making sure data is sent and received at the same rate. This prevents one computer from overwhelming another with data. Prevent Deadlock: Avoiding situations where two computers are waiting for each other, causing a standstill in data transmission.## Data Transmission Essentials Ensuring Data Integrity Deadlock makes sure that data doesn't collide, preventing packets from blocking each other during transmission. It ensures data is received without errors, maintaining data integrity. Layers of Data Transmission When transmitting data over the Internet, there are seven layers of processes: 1. Application 2. Presentation 3. Session 4. Transport 5. Network 6. Data Link 7. Physical For the IB exam, it's recommended to memorize any three of these layers. The physical layer involves the actual wires or wireless connection, while the application layer is like the website you're seeing e. g. , H T T P. Page 4  Created by Turbolearn AI Transmission Media Transmission media refers to the physical methods used to transmit data packets. Types of Transmission Media Wired: Ethernet T wistedP air: Commonly used with a square input. Copper: Includes copper wires and coaxial cables usedf orT V connections. Fiber Optic: Used for long-range, heavy-duty network connections. Wireless: Radio Waves Microwave Wi-Fi Factors to Consider When choosing a transmission medium, consider: Security: Can the connection be hacked? Reliability: How likely is data loss? Cost: What is the expense? Speed: How fast is the connection? Wi-Fi vs. Ethernet Factor Wi-Fi Ethernet Speed Slower Faster Less reliable More reliable Reliability ′ interf erencef romobjects, geography aslongasthecordiswell − insulatedandthere snoelectromagneticinterf erence Security Requires data encryption Data should still be encrypted, but harder to intercept Latency Higher latency slower Lower latency f aster Deployment Easier justsetupaW i − F irouter More complex requirescablesf oreachcomputer Fiber Optic vs. Copper Fiber optic cables are used for transmitting data at a faster rate over longer distances due to their high bandwidth. Feature Fiber Optic Copper e. g. , Ethernet Bandwidth Higher Lower Distance Longer Shorter Interference Not susceptible to electromagnetic interference or voltage surges Susceptible to electromagnetic interference Material Glass transmitslightpatterns Copper Wires Weight Lightweight Heavier Cost More expensive Less expensive Bending Requires a linear connection, cannot be sharply bent Can be bent Fiber optic is a piece of glass that transmits patterns of light at extremely high frequencies millions/billionsof timesasecond to transmit data, similar to Morse code but with light. Cost Comparison Page 5  Created by Turbolearn AI Fiber Optic: Most expensive Copper: Second most expensive Wi-Fi: Cheapest Factors Affecting Transmission Speed Primary Factor Traffic: The amount of data being sent at a given time. Higher traffic leads to slower network speeds. Secondary Factors Time of day: Network speeds can vary based on usage patterns throughout the day. Distance: Data transmission is less effective over longer distances. Infrastructure: The quality and setup of wiring. Additional Factors Environmental Factors: Temperature, interference. Financial Factors: The quality of equipment. Type of Data: Streaming data e. g. , N etf lix can slow transmission.## Data Compression Data compression is the process of reducing the size of data to make it smaller, which can be useful for sending data more quickly or storing more data in a set amount of space. There are two types of compression: lossy compression and lossless compression. Lossy compression removes data to make a file smaller, resulting in a loss of quality. This type of compression is often used for videos and images. Lossless compression uses an algorithm to reduce file size without losing any data. This type of compression is often used for text files and other data where quality is important. The main difference between lossy and lossless compression is that lossy compression is irreversible, meaning that once data is removed, it cannot be recovered. Lossless compression, on the other hand, allows the original data to be restored. Network Security Network security refers to the measures taken to prevent unauthorized access to a network. There are several ways to secure a network, including: Authentication: verifying the identity of users or devices Encryption: encoding data to prevent unauthorized access Media Access Control M AC addresses: controlling access to a network based on device addresses Firewalls: analyzing and controlling incoming and outgoing data packets Physical security: protecting network devices and data from physical threats Authentication There are three types of authentication: Type Description One-factor using something you know, such as a password authentication Two-factor using something you know and something you have, such as a password and a text message authentication Three-factor using something you know, something you have, and something you are, such as a password, a authentication fingerprint, and a facial recognition scan Page 6  Created by Turbolearn AI Encryption Encryption is the process of encoding data to prevent unauthorized access. It uses a private key or public key to encode and decode data. Media Access Control M AC addresses A MAC address is a unique address assigned to each network device. It can be used to control access to a network by creating a whitelist of allowed devices. Firewalls A firewall is a device or software that analyzes and controls incoming and outgoing data packets. It can be used to block unauthorized access to a network and prevent sensitive data from being sent outside the network. Physical Security Physical security refers to the measures taken to protect network devices and data from physical threats, such as: Locking doors and cages to prevent unauthorized access Using security guards to monitor the network Protecting against natural disasters, such as hurricanes and earthquakes Using EMP insulation to prevent magnetic interference Page 7