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Ports |
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TCP Port NumbersThe port numbers are divided into three ranges: the Well Known Ports, the Registered
Ports, and the Dynamic and/or Private Ports. The Registered Ports are those from 1024 through 49151
The Dynamic and/or Private Ports are those from 49152 through 65535 WELL KNOWN PORT NUMBERS The Well Known Ports are controlled and assigned by the IANA and on most systems can only be used by system (or root) processes or by programs executed by privileged users. Ports are used in the TCP [RFC793] to name the ends of logical connections which carry long term conversations. For the purpose of providing services to unknown callers, a service contact port is defined. This list specifies the port used by the server process as its contact port. The contact port is sometimes called the "well-known port". To the extent possible, these same port assignments are used with the UDP [RFC768]. The assigned ports use a small portion of the possible port numbers. For many years the assigned ports were in the range 0-255. Recently, the range for assigned ports managed by the IANA has been expanded to the range 0-1023. REGISTERED PORT NUMBERS The Registered Ports are not controlled by the IANA and on most systems can be used by ordinary user processes or programs executed by ordinary users. Ports are used in the TCP [RFC793] to name the ends of logical connections which carry long term conversations. For the purpose of providing services to unknown callers, a service contact port is defined. This list specifies the port used by the server process as its contact port. While the IANA can not control uses of these ports it does register or list uses of these ports as a convienence to the community. To the extent possible, these same port assignments are used with the UDP [RFC768]. The Registered Ports are in the range 1024-65535. DYNAMIC AND/OR PRIVATE PORTS The Dynamic and/or Private Ports are those from 49152 through 65535 REFERENCES [RFC768] Postel, J., "User
Datagram Protocol", STD 6, [RFC793] Postel, J., ed.,
"Transmission Control Protocol - DARPA Internet Program Protocol Specification",
STD 7,
This page on Port Numbers has been developed with information found at the Information Sciences Institute at the University of Southern California. |