The transport layer (TCP and UDP) (User Datagram Protocol, Transmission Control Protocol, TCP establishment and termination, Port numbers, Protocol usage by common Internet applications),
TCP Client-Server example (TCP Echo server, Normal startup, Normal termination, Posix Signal Handling, Handling of SIGCHLD signals, wait() functions, Termination of server process, Crashing/Shutdown of server host), και
Sect. 8:
Elementary UDP sockets (recvfrom() and sendto() functions, UDP Echo server, Lost Datagrams, Verifying Received Response).