Chapter 10 Install and System Administration for FortiOS 5.0 : Session helpers : Oracle TNS listener session helper (tns)
  
Oracle TNS listener session helper (tns)
The Oracle Transparent Network Substrate (TNS) listener listens on port TCP port 1521 for network requests to be passed to a database instance. The Oracle TNS listener session helper (tns) listens for TNS sessions on TCP port 1521. TNS is a foundation technology built into the Oracle Net foundation layer and used by SQLNET.
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)
Remote shell session helper (rsh)
Real-Time Streaming Protocol (RTSP) session helper (rtsp)
Session Initiation Protocol (SIP) session helper (sip)
Trivial File Transfer Protocol (TFTP) session helper (tftp)