4-Port ADSL Router User Manual

Configuring Network Address Translation
60
The [NAT Configuration] page contains the following elements:
•
The [NAT Options] drop-down list will provide access to the
[NAT Configuration] page and [NAT Global Information] table
(shown by default and in Figure 16), the [Network Address
Translation (NAT) Rule Configuration] page (see Figure 18)
and the [NAT Translations]
page (see Figure 20).
•
The [Enable] and [Disable] radio buttons will allow you to turn
on or off the NAT feature.
•
The [NAT Global Information] table will display the following
settings that apply to all NAT rule translations:
Field Description
TCP Idle Timeout
(sec):
TCP Close Wait
(sec):
TCP Def Timeout
(sec):
When two computers communicate via the Internet,
a TCP-based communication session is created between them
to control the exchange of data packets. The TCP session can
be viewed as being in one of three states, depending on the
types of packets being transferred.
-
The establishing state, where the connection is being set up.
- The active state, where the connection is being used to
transfer data.
- The closing state, in which the connection is being shut down.
When a NAT rule is effective on a TCP session in the active
state, the session will timeout if no packets are received for
the time specified in [TCP Idle Timeout].
When in the closing state, the session will timeout if no packets
are received for the time specified in [TCP Close Wait].
When in the establishing state, the session will timeout
if no packets are received for the time specified in [TCP
Def Timeout].
UDP Timeout
(sec):
Same as TCP Idle Timeout, but for UDP-based
communication sessions.
ICMP Timeout
(sec):
Same as TCP Idle Timeout, but for ICMP-based
communication sessions.