ZyXEL Communications Intelligent Broadband Sharing Gateway P-324 - Manual (Page 160)

13-2 Filter Configuration
Figure 13-1 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
13.1.1 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 cannot mix device filter
rules and protocol filter rules within the same set. 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
Drop packet
if line not up Drop packet
if line not up
Send packet
but do not reset
Idle Timer
Send packet
but do not reset
Idle Timer
Match Match Match
No
match
No
match
No
match
Call Filtering