Port

TCP/IP Port

Port(P)

Name Environment Usage Description Data Type Remarks See also

Name

Port

Environment

Windows

Usage

[Form.]Ucm.Port = value$

Description

The Port property identifies the TCP/IP port number the server process is operating on. The value can be set as numeric value (e.g. "7001") or as symbolic alias name as defined in the TCP/IP services file. On Unix systems, this file is located in the /etc directory. On Windows systems the location varies depending on OS type and version. Each line in the services file holds the service name, a port number and a port type (for UCM communication the type should always be tcp). To avoid conflicts with standard TCP/IP ports, these numbers should have values > 5000 assigned by convention. Unitec products use port numbers in the range from 6800 to 6999.

Once both set, the Host and Port properties reduces the I/O scope to messages from that service in the communication space CommID (and - as always - to messages with the same ID as defined by the InputID property). If Port is not set, messages from any source that match InputID will be received and output is forwarded to all UCM controls on the local system that have their Service, Host and Port properties cleared too.

The Port property is meaningful only with AdrMode set to ucmTCP.

Data Type

String

Remarks

In addition to port number the IP address, the ucmTCP addressing mode requires the setting of a valid IP address or host alias name in the Host property. For local communication neither the Host nor the Port property should be set.

A connection is established upon the first send operation of the control. If a socket with identical Host, Port and CommID already exists, the control uses this existing communication link. Note, that this may also occur indirectly when the line was established using a synonym Service property with addressing mode ucmService.

Important note:

In TCP/IP programming a communication link between a server and a client is established by the use of a entity called socket, introduced by UCB University of California at Berkley, also referred to by BSD sockets. A socket is defined by the IP address of the two participating systems and a so called port number. Port numbers often have a symbolic service name assigned in a control file named services, but internally the number is used as is. Many well known port numbers (reserved services) are defined in the rage between 1 and 1023, but room should be left for extensions. By convention, user port numbers should have values > 5000 assigned. Unitec software uses port numbers in the rage 6800 to 6999, e.g. for a future version of the license manager the port 6800 has been reserved and the CSS spooler uses port 6801. To avoid conflicts with standard TCP/IP and Unitec ports, you should use numbers in the range 5001 to 6799 or >= 7000.