DSL-302G ADSL Modem User’s Guide
NAT
Network Address Translation is a method for disguising the private IP addresses you use on your LAN as the
public IP address you use on the Internet. You define NAT rules that specify exactly how and when to translate
between public and private IP addresses.
NAT is enabled by default. You can enable or disable NAT by selecting the
Enable
or
Disable
option in the
configuration menu and submitting the settings.
NAT Configuration
Information displayed in the NAT Configuration is summarized below:
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 in 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, and the
closing state
, in which the connection is being shut down. When a NAT
rule is in effect 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.
GRE Timeout(sec)
Same as TCP Idle Timeout, but for GRE-based communication sessions.
Default Nat Age(sec)
Same as TCP Idle Timeout, but for GRE-based communication sessions.
NAPT Port Start/End
When an NAPT rule is defined, the source ports will be translated to
sequential numbers in this range.
45
