Xerox 4850 Installation Planning Manual page 189

Defining the printer to the host: TCP/IP attachment
Considerations for
configuring TCP/IP
for MVS
F-15
Following are some considerations for configuring TCP/IP for
MVS:
• To specify a TCP/IP address space name other than the
default (TCPIP), code the following EXEC statement in the
appropriate PSF writer procedure:
STEP01 EXEC PGM=APSPPIEP,
PARM=(,,,,tcpip_name), REGION=4096K
where tcpip_name is the name of the TCP/IP address space.
If this parameter is not coded, PSF uses the default name,
TCPIP. (For a full description of the PARM parameter, refer to
Print Services Facility/MVS: Diagnosis Guide and
Reference.)
• KEEPALIVEOPTIONS statement: PSF relies on TCP to
detect when a connection with the printer is no longer usable.
When no data has been exchanged between PSF and its
connection partner, TCP sends keep-alive probes to the
connection partner periodically. These periodic probes, called
keep-alive transmissions, enable TCP to discover when a
connection is no longer usable, even if the connection partner
is abruptly powered off or is no longer accessible through the
network.
The frequency of keep-alive transmissions is controlled by
the INTERVAL parameter on the KEEPALIVEOPTIONS
statement. The frequency applies to all TCP applications that
direct TCP to send keep-alive transmissions. The default
frequency is after about two hours of inactivity.
For printing on the NPS/IPS, it is recommended you specify a
shorter interval than the default—such as 10 minutes—for the
interval between keep-alive transmissions. Also, unless any
target host requires that the keep-alive packet contain data,
specify SENDGARBAGE FALSE. For example:
KEEPALIVEOPTIONS INTERVAL 10 SENDGARBAGE
FALSE ENDKEEPALIVEOPTIONS
If you change any of the values in the TCP/IP profile, restart
TCP/IP to pick up the changes.
Installation Planning Guide