DIR_EPS_ROOT is a SAP Parameter attribute which is used to control root path for EPS file transfer 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 .
Base directory for transferrring files with EPS. If a WAN connection and
the directory specified here exists, files can be transferred by RFC in
transaction SEPS.
The subdirectories log, in, out must exist.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.