Data communication means exchange of data between two devices through a medium.
For communication to happen, devices must be connected and use rules (protocols).
There are five main elements:
The actual data (text, image, audio, video).
Device which sends data.
Examples: Computer, Phone.
Device which recieves data.
Examples: Printer, Phone.
Path where data travels.
Examples: Cable, WiFi, Fiber Optic.
Rules that govern communication.
Example: TCP/IP,HTTP.
The data must reach the correct destination. It should be delivered to the right device or user.
The data must be received without any errors. No changes or corruption should occur during transfer.
The data must be delivered on time. Especially important for real-time communication like video calls or online gaming.
Jitter means the variation in delay during data transfer.
Low jitter = smooth audio/video.
High jitter = lag, disturbances.
One-way communication
Example: TV → User
Two-way, but one at a time
Example: Walkie-Talkie
Two-way at same time
Example: Mobile Phone Call
Cheap, used in LAN.
Used in TV cables.
Fastest, uses light, no interference.
Protocols are rules that control data transfer.
✓TCP/IP - Main internet protocol ✓HTTP/HTTPS - Web browsing ✓FTP - File transfer ✓SMTP - Sending emails ✓POP/IMAP - Receiving emails ✓VoIP - Voice over IP (Whatsapp call)
✓Data communication = exchange of data between devices ✓Optical fiber = fastest medium ✓Sender-Receiver-Message-Medium-Protocol = 5 elements ✓Simplex = one direction ✓Full duplex = two-way same time ✓HTTP protocol used for → Web browsing ✓FTTP = File transfer ✓SMTP = Sending email ✓POP/IMAP = Receiving email