Socket API
The Berkeley socket API for GATE CS: the call sequence of a TCP server (socket, bind, listen, accept, recv and send, close), a TCP client (socket, connect) and UDP endpoints (sendto, recvfrom), which call triggers which segments of the handshake and teardown, which calls block and until when, the new socket returned by accept, byte-stream versus datagram reads, port and address rules, concurrent servers, and the usual wrong orderings.