DISCUS™ Multiplay Wireless VoIP AG
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OGU 930500105-A1
Security Section
The Router firewall supports advanced filtering, designed to allow comprehen-
sive control over the Firewall’s behavior. You can define specific input and out-
put rules, control the order of logically similar sets of rules and make a
distinction between rules that apply to WAN and LAN network devices.
GENERAL
Use the 'General' screen to configure the gateway's basic security settings.
The firewall regulates the flow of data between the home network and the
Internet. Both incoming and outgoing data are inspected and then either
accepted (allowed to pass through the Router) or rejected (barred from pass-
ing through the Router) according to a flexible and configurable set of rules.
These rules are designed to prevent unwanted intrusions from the outside,
while allowing home users access to the Internet services that they require.
The firewall rules specify what types of services available on the Internet may
be accessed from the home network and what types of services available in
the home network may be accessed from the Internet. Each request for a ser-
vice that the firewall receives, whether originating in the Internet or from a
computer in the home network, is checked against the set of firewall rules to
determine whether the request should be allowed to pass through the firewall.
If the request is permitted to pass, then all subsequent data associated with
this request (a “session”) will also be allowed to pass, regardless of its direc-
tion.
For example, when you point your Web browser to a Web page on the Inter-
net, a request is sent out to the Internet for this page. When the request
reaches the Router the firewall will identify the request type and origin - HTTP
and a specific PC in your home network, in this case. Unless you have config-
ured access control to block requests of this type from this computer, the fire-
wall will allow this request to pass out onto the Internet. When the Web page is
returned from the Web server the firewall will associate it with this session and
allow it to pass, regardless of whether HTTP access from the Internet to the
home network is blocked or permitted.
The important thing to note here is that it is the origin of the request, not sub-
sequent responses to this request, that determines whether a session can be
established or not. You may choose from among three pre-defined security
levels for the Router: Minimum, Typical, and Maximum (the default setting).
The table below summarizes the behavior of the Router for each of the three
security levels.