Xerox 4500 PS TR instruction manual Keepalive support for OS/2, Select Port Number

PSF/2 AFP Printing Using TCP/IP

Xerox 4500 PS TR

8.Select Port Number

If the output device is attached to PARALLEL 1 of the print server, then select TCP/IP port number 5001. The value 5002 may also be used. The value chosen must match the value defined for the session in the PrintServer (IPDS)

9.Select OK

10.Select Create

The device created can be used with PSF/2 direct and with PSF/2 DPF printing methods.

17.2 KEEPALIVE support for OS/2

The TCP/IP components in OS/2 offer network attachment for printers. However, these TCP/IP components do not always detect connection failures if a point-to-point session between the OS/2 machine and the device has failed (e.g. in connection with a printer being abruptly powered off). This may result in serious problems for IPDS printers in sessions with PSF/2.

Now, support for the TCP KEEPALIVE facility has been added to the TCP/IP components of OS/2 to detect all communication failures. PSF/2 directs TCP to send a KEEPALIVE transmission on a TCP connection remaining inactive for an extended period. If the KEEPALIVE transmission is not acknowledged, the TCP assumes that the connection partner has been lost and subsequently reports a failure to PSF/2.

The frequency of these transmissions depends on the configuration of the OS/2 TCP/IP environment. The default for OS/2 is two hours or more. This, however, can be adjusted. These values apply to all TCP applications that request KEEPALIVE transmissions.

In the following, you are provided with instructions for using the KEEPALIVE support facility added to the TCP/IP components for OS/2.

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