Fortigate Service TTL

This article describes how to change the session TTL for a specific port. In this example it is telnet.

config system session-ttl
 set default 1800
 config port
 edit 23
  set protocol 6
  set timeout 3600
  set start-port 23
  set end-port 23
 next
end

The session timeout is in seconds.
Protocol 6 is TCP.
Protocol 17 is UDP.
If you leave the protocol on 0, it is valid for all protocols.