The OSI model is a conceptual framework that standardizes the functions of a telecommunication or computing system into seven layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application. It’s important for troubleshooting network issues, as it helps IT professionals understand how data flows across networks.

I would start by checking physical connections (cables, switches, routers). Next, I’d verify the network settings (IP address, subnet mask, gateway) on the device. I’d then use tools like ping and tracert to test connectivity and isolate the problem’s location.

TCP (Transmission Control Protocol) is connection-oriented and ensures reliable data transmission with error checking and flow control. UDP (User Datagram Protocol) is connectionless, offering faster transmission but without the reliability guarantees, making it suitable for real-time applications.