Chapter 10 Install and System Administration for FortiOS 5.0 : Session helpers : Remote shell session helper (rsh)
  
Remote shell session helper (rsh)
Using the remote shell program (RSH), authenticated users can run shell commands on remote hosts. RSH sessions most often use TCP port 514. To accept RSH sessions you must add a security policy with service set to any or to the RSH pre-defined service (which listens on TCP port number 514).
FortiOS automatically invokes the rsh session helper to process all RSH sessions on TCP port 514. The rsh session helper opens ports required for the RSH service to operate through a FortiGate unit running NAT or transparent and supports port translation of RSH traffic.
See Also
Viewing the session helper configuration
Changing the session helper configuration
DCE-RPC session helper (dcerpc)
DNS session helpers (dns-tcp and dns-udp)
File transfer protocol (FTP) session helper (ftp)
H.245 session helpers (h245I and h245O)
H.323 and RAS session helpers (h323 and ras)
Media Gateway Controller Protocol (MGCP) session helper (mgcp)
ONC-RPC portmapper session helper (pmap)
PPTP session helper for PPTP traffic (pptp)
Real-Time Streaming Protocol (RTSP) session helper (rtsp)
Session Initiation Protocol (SIP) session helper (sip)
Trivial File Transfer Protocol (TFTP) session helper (tftp)
Oracle TNS listener session helper (tns)