Computer networks
Layers, frames, error detection, subnetting, routing algorithms, TCP and network performance: the networking course of a computer science degree.
Course · 8 lessons · 60 min
- 1Layered models: OSI and TCP/IPFreeWhy networks are built in layers, how the seven OSI layers map onto the four of TCP/IP, and how much each header costs on the wire.1977–1989 · 7 min
- 2The link layer: Ethernet, switching and VLANsHow a frame is laid out, what a MAC address encodes, how a switch learns where hosts are, and how 802.1Q tags split one switch into many LANs.1973–today · 8 min
- 3Error detection: parity, checksums and CRCWhy bits flip, what parity and Hamming distance can and cannot catch, how the internet checksum is computed by hand, and why links use a CRC.1947–1988 · 7 min
- 4IP addressing and subnettingPrefixes and masks in binary, network and broadcast addresses, host counts, and a worked VLSM plan that packs five subnets into one /24.1981–2006 · 8 min
- 5Routing algorithms: distance vector and link stateHow routers compute paths: Bellman–Ford and count-to-infinity in RIP, flooding and Dijkstra in OSPF, with a shortest-path tree worked by hand.1956–1998 · 8 min
- 6Network performance: delay, throughput and the bandwidth-delay productThe four components of delay, why bandwidth is not throughput, and how the bandwidth-delay product sets the window a fast long-distance transfer needs.1988–today · 7 min
- 7TCP: connections, flow control and congestion controlSequence numbers and the three-way handshake, the receiver's window, and how slow start and AIMD keep senders from collapsing the network.1981–2022 · 8 min
- 8UDP and application-layer protocolsWhat UDP adds to IP and what it leaves out, how ports demultiplex traffic, how application protocols are designed, and why QUIC runs over UDP.1980–2021 · 7 min