Prestige 201 ISDN Access Router
6-2 Filter Configuration
Figure 6-1 Outgoing Packet Filtering Process
For incoming packets, your Prestige applies data filters only. Packets are processed depending upon whether
a match is found. The following sections describe how to configure filter sets.
The Filter Structure of the Prestige
A filter set consists of one or more filter rules. Usually, you would group related rules, e.g., all the rules for
NetBIOS, into a single set and give it a descriptive name. The Prestige allows you to configure up to twelve
filter sets with six rules in each set, for a total of 72 filter rules in the system.
You can apply up to four filter sets to a particular port to block multiple types of packets. With each filter set
having up to six rules, you can have a maximum of 24 rules active for a single port. The following diagram
illustrates the logic flow when executing a filter rule.
Data
Filtering
Outgoing
Packet
Drop
packet
Built-in
default
Call Filters
User-defined
Call Filters
(if applicable)
Initiate call
if line not up
Active Data
Send packet
and reset
Idle Timer
Or Or
if line not up
if line not up
Send packet
but do not reset
Idle Timer
Send packet
but do not reset
Idle Timer
Match MatchMatch
No
match
No
match
No
match
Call Filtering
