The LAN inactivity timer (LANINACTMR) parameter of your Systems Network Architecture (SNA) controller description determines how long your system waits before requesting a response from the remote station. Your system uses the request to test if the remote station is still accessible.
Performance problems:
Unnecessary traffic is created if the value that you specify for the LANINACTMR parameter is too small. This might lead to a performance throughput problem. If it is too large, your system might not find out as quickly that the remote station is inaccessible.
LANINACTMR is sensitive to whether the remote station is on the same LAN or not. If the station is across a bridge, you might need to increase this value. If the value is 0 (no time out), you will not be informed if the connection fails until your system attempts a data transfer.
To change these parameters, you should see Change timing parameters.