udp
2 free lessons tagged udp across Computer Science. Each one is a short sequence of focused steps with narration and a five-question quiz at the end — take them in any order, no signup required.
DNS, HTTP, and the Move to QUIC
Before a byte of HTTP moves, a name has to become an address. Follow the full resolution path from stub resolver to authoritative server, see how TTLs govern change, then trace head-of-line blocking from HTTP/1.1 through HTTP/2's TCP problem to HTTP/3 running on QUIC over UDP.
TCP: Reliability, Windows, and Congestion
TCP turns a lossy packet service into an ordered byte stream, and almost every performance surprise on the internet comes from how it does that. Work through the handshake, cumulative ACKs, retransmission timers, the two windows, slow start and AIMD, CUBIC versus BBR, bufferbloat, and when to reach for UDP instead.