01-04-2014, 04:57 PM
PORT NUMBERS
PORT NUMBERS.pdf (Size: 200 KB / Downloads: 35)
The port numbers are divided into three ranges: the Well-Known Ports, the
Registered Ports, and the Dynamic and/or Private Ports.
♦ The Well Known Ports are those from 0 through 1023.
♦ 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 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.