Hardware manual

80-001113 SysLINK Administrator’s Guide Page 21
Network Translation
The gateway is capable of accepting incoming TCP connections and redirecting them to
remote TCP hosts. This functionality is called network translation and behaves much like a
TCP "pipe" between two systems.
It is also possible to modify the network protocol traveling through the TCP pipe by using
the Protocol Settings page to define the remote host's protocol requirements. The most
common use for this functionality is to add SSL encryption to an incoming TCP connection
prior to sending it along to the remote host.
The Network Translation table is used to define network mappings for TCP pipes. You must
first specify the incoming TCP port to which your device or application will connect. Then,
you must specify the outgoing hostname and destination TCP port for the TCP pipe.
You may also specify the source TCP port for the outgoing TCP connection. Usually, this
should be set to 0 to allow automatic selection of the source port. However, if you have a
firewall that imposes limits on source TCP ports then you may need to set this to something
specific. Note that if you specify something other than 0, you will be limited to only 1 TCP
pipe at-a-time for any given destination port.
In the example above, if the gateway receives an incoming TCP connection on TCP port
5000, a TCP pipe will be established to www.myhost.com on TCP port 443. Since the TCP
source port is 0, any number of simultaneous connections are allowed and the TCP source
port will be automatically chosen for each one.
As in the phone number translation table, the protocols for the outgoing Host and TCP Port
combinations are defined in the Protocol Settings page.