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(Hz) area More prone to 3: NETWORKS & THE INTERNET Better for devices interference being moved More devices often...

(Hz) area More prone to 3: NETWORKS & THE INTERNET Better for devices interference being moved More devices often use this Computer Communications Efficient already Process of sharing data, programs, and info between devices (emails, texts, 5G Higher data range Smaller coverage (Hz) Less prone to area electronic commerce) interference Connectivity: using networks to link people and resources Theoretical Speeds Physical Maximum speed the device can do Fiber Optic Cables assuming ideal conditions, which almost Transmit data as pulses of light through never happen tiny tubes of glass Download + upload speed Speeds of 1 petabit per second were Based on just one connected device measured (petabit = 1M gigabits) Does not factor interferences Lighter faster, and more reliable at transmitting data than coaxial cables Real world speeds Shared bandwidth between all devices Speed Interference from environment & other Bits: Mbps, Gbps electronics, even other wi-fi connections ○ Data transfer speed Signal loss depending on how far the Bytes: MBps, GBPS device is ○ File sizes Ratio of Bytes to bits (usually) Satellites ○ 1:8 ratio Orbiting 22 miles above earth as ○ Example: advertised, 100 Mbps microwave relay stations. Bad weather connection : 12MB of size can interrupt data flow (uplink and transferred per seconds downlink) ○ Congestion and cable distances will affect overall connection GPS (Global positioning system) speed Satellites help facilitate this to uniquely determine the geographic location of a Wireless: covering a lot more ground rather device easily Bluetooth: Short-ranged radio Connection Devices communication standard (33 meters), Bandwidth most of us use Rate of information transfer, how much WiFi : Wireless fidelity, which uses high information can move across it frequency radio signals. Connections vary Most device let you control the bandwidth in terms of data transfer speed & (to help other connected devices) frequencies used. Internet speeds between your application can decrease as you run more PROS CONS internet-needed tasks Tasks will need varying bandwidth 2.4G Larger coverage Lower data rate amount Connections can be provided by diff kinds of ISP Client: shares/uses resources from other (Internet Service Provider) → DDCFSC nodes 1. Dial up: uses existing telephones and Server: shares resources with other telephone modems nodes 2. DSL: uses existing telephone lines, diff Can handle very large networks, monitor frequencies. Asymmetric DSL (ASDL): network activities most frequently used types Ex. email servers and helping emails get 3. Cables: facilitate connections between to and from places, software running on devices servers which allows admin to handle all 4. Fiber-optic service (FiOS) email accounts hosted on that server 5. Satellites: used but slower than DSL & cable, available almost everywhere Peer to peer: nodes are both client & server 6. Cellular: provides support voice & data Common way to share games, movies, transmission to wireless devices music on internet Easy and inexpensive, sometimes free Network Architecture and strategies Lacks security and management, if you Network communication systems don't set it up properly, people can Connect 2 or more computers so they access exchange info and share resources Ex. files sharing setups, torrent sites Consist of three parts (each part can consist of multiple devices) Network Etiquette: communication protocols ○ Nodes: any device that is Protocols connected to a network (can be Mutually agreed upon set of rules and computer, printer, data storage conventions for efficient data transfer device) Set up as a multilayered hierarchy → ○ Routers: nodes that forwards or changes on any layer does not cause route data packets from one changes to the other components network to their destination in Ex. TCP/IP where in each layer has its another network own set of tasks to deal with how info will ○ Switches: central nodes that flow and get processed coordinate the flow of data by sending messages directly IP Address: helps identify your device between sender and receiver (think like an actual home address) nodes Port: application/service your computer is running Network Architecture A port number can run from 0 to 65,535 Describes how a network is arranged and Well known/used ones run from 0-1024 how resources are coordinated and Certain reserved values are found shared 1024-49151 Find diff topologies & strategies The rest are free to use by everyone else Helps segregate thing, if they mix, certain Network Strategies: how data/info can flow changes can affect diff services between places Client/server: central computers coordinate & HTTP:// (hypertext transfer protocol) supply services to other nodes Protocol under application layer  Set of guidelines for implementing Firewalls end-user services provided by the Limit access to certain things network Programs/devices that control what info E.g.: how you can access website from the current network will get to your ○ Utilizes universal resource actors, private network commonly referred to as URLs Implement rules on file transfer, web ○ Methods that deal with website servers, communication data: GET, DELETE, POST, Control what websites/content devices PATCH, etc. can access HTTP replies: given a certain status code ○ Ex. blocking socmed/streaming to easily denote them (OBFNI) Important so hackers cannot access info, ○ 200: OK, 400: Bad Request, 403: especially when there are security Forbidden, 404: Not found, 500: mishaps Internal Server Error VPN: virtual private network ICMP: Internet control message protocol Like an encrypted “tunnel” between you Helps communicate error messages and and the server you are connecting to status conditions within networks Encryption: converting data into a Ping: packet internet groper, to check if particular code based on some the host (the other devices) is reachable formula/algorithm, conceal important data ○ Verifies that a computer can and prevent unauthorized access communicate over the network Mask location and identity since your with another device device has a diff IP address ○ Ex. games, ping gives the Plain text → Ciphertext: shifted 3 letters network latency between a backs player’s client & gamer server Common reasons (lower ping = lower delay, higher ○ Connecting on public networks: ping = longer delay) public WiFIs you aren't sure with ○ Internet service providers (ISP): DNS: Domain Naming System can see your online activity even Utilizes host names, which translate to if you’re private browser or their IP address equivalents incognito mode For example: canvas.ateneo.edu ○ Accessing content blocked in ○ Canvas: subdomain your region: Netflix episodes not ○ Ateneo: 2nd level domain available in the PH ○ Edu: top level domain