gw/rem_start is a SAP Parameter attribute which is used to control How to start remote executables 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 determines how remote CPIC programs are to be started:
Start via remote shell
Start via secure shell
Start via rexec
Remote starting of programs deactivated. Remote programs to be started
via remote shell always run under the "gateway" identification. If
remote programs are started using rexec, they run under the
identification defined by the parameters SAPUSERNAME and SAPPASSWORD.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.