gw/resolve_timeout is a SAP Parameter attribute which is used to control Timeout for net lookup calls 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 .
You can use this parameter to activate time measurement for network
calls. If a call takes longer than the specified period of time, the
call, its parameters and the time required are logged in the trace file
dev_rd.
This can identify problems with the network configuration.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.