This is a list of TCP and UDP port numbers used by protocols of the Internet protocol suite for operation of network applications.
The Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP) needed only one port for full-duplex, bidirectional traffic. The Stream Control Transmission Protocol (SCTP) and the Datagram Congestion Control Protocol (DCCP) also use port numbers. They usually use port numbers that match the services of the corresponding TCP or UDP implementation, if they exist.
