Carrier Access Multi-Service Router (MSR) Card MSR/Adit 3K GUI - Manual (Page 158)

4-4 Adit 3000 (Rel. 1.6) and MSR Card (Rel 2.0) GUI
Security
General
General
Use the General tab to configure the Adit’s basic security settings.
The firewall regulates the flow of data between the network and the Internet. Both incoming and
outgoing data are inspected and then accepted (allowed to pass through the Adit) or rejected (barred
from passing through the Adit) according to a flexible and configurable set of rules. These rules are
designed to prevent unwanted intrusions from the outside while allowing 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
network and what types of services available in the network may be accessed from the Internet. Each
request for a service that the firewall receives, whether originating from the Internet or from a computer
in the network, must be 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, all subsequent data associated
with this request (session) will also be allowed to pass, regardless of its direction.
For example, when you point your web browser to a web page on the Internet, a request is sent out to
the Internet for this page. When the request reaches the Adit, the firewall identifies the request type and
origin (HTTP and a specific PC in your network, in this case). Unless you have configured access
control to block requests of this type from this computer, the firewall allows this request to pass out onto
the Internet. When the web page is returned from the web server, the firewall associates it with this
session and allows it to pass, regardless of whether HTTP access from the Internet to the network is
blocked or permitted.