3Com OfficeConnect 3C857, User Manual

Page: 63 / 120

Firewall 63
The port numbers are specified using a comma-separated list, with
hyphens to denote port number ranges. So for example, entering
2, 3,
5-7 would cause ports 2, 3, 5, 6, and 7 to be activated.
Special Applications
Figure 49 Special Applications Screen
Select Special Applications tab to display Authorized Application setup
screen. ( Figure 49 )
Some software applications require special or multiple connections to the
Internet and these would normally be blocked by the firewall. For
example Internet Telephony or Video conferences require multiple
connections.
So that these special applications can work properly and are not blocked,
the firewall needs to be told about them. In each instance there will be a
trigger port and incoming port(s), where traffic on the trigger port tells
the firewall to open the incoming ports.
Each defined Special Application only supports a single computer user,
and up to 10 Special Applications can be defined. Any incoming ports
opened by a Special Application trigger will be closed after five minutes
of inactivity.
To configure special applications:
1 Click New .
2 Select the applications from the pull-down list. ( Figure 50 )