The rscsi command is a remote generic SCSI transport server program.
rscsi is a program that is run locally on the machine with SCSI
devices, it is used by remote programs like cdrecord(1), cdda2wav(1),
readcd(1), and sformat(1) that like to access SCSI devices through an
interprocess communication connection via libscg.  rscsi is normally
started up with an rexec(3) or rcmd(3) call but it may also be
connected via an internal pipe to an ssh(1) session that was set up by
the remote user.

The rscsi command must be installed setuid root for full functionality.
For this reason it is provided as a separate package to cdrtools.