🌐Systems & Networks
Network Algorithms
Exchanging data through layers and protocols. Learn the 2 topics below step by step with interactive visualizations.
🌐OSI Model
The OSI 7-layer model standardizes network communication into seven layers: application, presentation, session, transport, network, data link, and physical. Each layer has an independent role, and data moves up and down the layers through encapsulation and decapsulation, attaching and removing headers.
7 Layers · Encapsulation🌐TCP Handshake
Before exchanging data, TCP confirms both directions are ready with a 3-way handshake, and when finishing it closes each direction in turn with a 4-way handshake. Each step exchanges SYN, ACK, and FIN flags along with sequence numbers (seq/ack), and both sides' connection state changes step by step.
3-way · 4-way