TCP Port Setup

TCP, or Transmission Control Protocol, provides a method of sending data and verifying the correct delivery of that data from client to server. Without a protocol such as TCP data can get lost during transmission or packets can arrive out of order. TCP provides support to detect errors or lost data, and to trigger re-transmission until the data is correctly and completely received.

TCP guarantees the delivery of data and also guarantees that packets will be delivered in the same order in which they were sent. This reliability, however, is achieved at the cost of transmission protocol overhead, which increases the amount of data to be transferred. This can, in some extreme instances, delay of the receipt of the data or exceed the bandwidth of the network.

TCP Port Configuration

The NetRS supports a wide range of services on its TCP ports. You can create a TCP port from the I/O Port Summary page by selecting Create New TCP Port. You must enter a TCP Port Number. See the discussion below for guidance on picking those. You can also choose whether to use Port Authentication when clients attempt to make connections. Beyond that, select a Service type and enter the service-specific options.

Using TCP Ports

The exact method for using a configured TCP port depends on the client platform, the Service in use, and the user's application program. At the lowest level, all that is usually needed is to establish a TCP socket connection to the NetRS IP address and the desired port number. For most services, data will begin flowing through the socket connection, from the NetRS to the client where it can be saved, parsed, displayed, etc. In general, multiple clients can connect to the same TCP Port at the same time, and the same data will flow to all of the clients.

Port Numbers

The IANA, Internet Assigned Numbers Authority, manages the assignment of TCP and UDP ports from 0-1023.

Port Ids from 0-1023 should not be used. These ports are designated as well-known ports and have been assigned specific functions by the IANA. On most systems these ports can only be used by system processes or processes executed by priveledged users.

Port numbers 1024 - 49151 are called registered ports. They are used as logical connections to carry on long term conversations. On most systems these ports can be used by ordinary user processes. They are not controlled by the IANA, although the IANA registers their use as a convenience to the user community.

Port numbers 49152 - 65535 are called dynamic and/or private ports, and use of these ports should be avoided.

The IANA provides a list of accepted port number assignments that can be found at the following location:

http://www.iana.org/assignments/port-numbers



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