User`s guide

ADSL/VoIP Gateway User’s Guide
55
11 Advanced Security
Your device has built in advanced Security features that protect
your network by blocking unwanted traffic from the Internet.
If you simply want to connect from your local network to the
Internet, you do not need to make any changes to the default
Security configuration. You only need to edit the configuration if
you wish to do one or both of the following:
• allow Internet users to browse the user pages on your local
network (for example, by providing an FTP or HTTP server)
• play certain games which require accessibility from the
Internet
This chapter describes how to configure Security to suit the
needs of your network.
By default, the IP addresses of your LAN PCs are hidden from
the Internet. All data sent from your LAN PCs to a PC on the
Internet appears to come from the IP address of your device.
(To display your device’s IP address, see Current Status on
page 24.) In this way, details about your LAN PCs remain
private. This security feature is called Network Address
Translation (NAT).
Configuring NAT Security
Certain network games, chat or file sharing software do not
work with your default NAT setting. Your device knows the port,
protocol and trigger information needed to allow access to the
common applications listed below, but by default, access to
them is disabled.
Application TCP
port
number
UDP
port
number
Trigger
required?
E-mail 110, 25 N/A false
News 119 N/A false
MSN Messenger 1863 N/A false
Yahoo! Instant Messenger
5050
5055
5100
N/A false
AOL Instant Messenger 5190 N/A false
Internet Relay Chat (IRC) 194 194 false
1720 N/A true
N/A 1719 true
Netmeeting (h323)
1731
522
N/A false
Real Audio
544
7070
544
6770
false