gw/conn_disconnect is a SAP Parameter attribute which is used to control Timeout to remove connections in state DISCONNECT information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
This parameter defines the time after which connections in status
DISCONNECT are released.
A connection goes into the status DISCONNECT when one side of the
connection breaks off due to an error, but the other side has read the
error information.
A value of 0 deactivates the release of such connections.
This check can be performed a maximum of every
See SAP Parameter Documentation for full SAP documentation for this profile parameter.