Owner's Manual

Advanced Configuration
61
N300 Wireless Gigabit ADSL2+ Modem Router DGN3500
Figure 36.
The WAN Setup fields are described in the following table:
Table 5.
Setting Description
Connect Automatically, as
Required
Usually, this check box is selected, so that an Internet connection is made
automatically, whenever Internet-bound traffic is detected. If this causes high
connection costs, you can clear the check box to disable this feature.
If this setting is disabled, you must co
nnect manually, using the screen that
you access by clicking the Connection Status button on the Status screen.
If you have an Always on connection, this setting has no effect.
Enable PPPoE Relay Selecting this check box allows a PPPoE client on a local
PC to connect to a
remote PPPoE server with the wireless modem router acting as a relay agent.
Disable Port Scan and DOS
P
rotection
The firewall protects your LAN against port scans and denial of service (DOS)
attacks. This protection should be disabled only in special circumstances.
Default DMZ Server This feature is sometimes helpful when you are using some online games and
video confrencing. Be careful when using this feature because it makes the
firewall security less effective. See the following section, Setting up Static
Routes on p
age 71.
MTU Size (in bytes) The normal MTU (Maximum Transmit Unit) valu
e for most Ethernet networks
is 1500 bytes, or 1492 Bytes for PPPoE connections. For some ISPs you
might need to reduce the MTU. This is rarely required, and should not be done
unless you are sure it is necessary for your ISP connection.
Disable SIP ALG The Session Initiation Protocol (SIP) Ap
plication Level Gateway (ALG) is
enabled by default to optimize VoIP phone calls that use the SIP. The Disable
SIP ALG check box allows you to disable the SIP ALG. Disabling the SIP ALG
might be useful when running certain applications.