The Filter Structure Of The Prestige; Figure 7-1 Outgoing Packet Filtering Process - ZyXEL Communications Prestige 316 User Manual

Prestige 316 Broadband Sharing Gateway/Wireless LAN
Outgoing
Data
Packet
Match
Drop
packet
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.

7.1.1 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.
Three sets of factory default filter rules have been configured in Menu 21 to prevent NetBIOS traffic from
triggering calls and to prevent incoming telnetting. A summary of their filter rules is shown in the figures
that follow.
The following diagram illustrates the logic flow when executing a filter rule.
7-2
Call Filtering
No No
Built-in
match match
default
Call Filters
Match
Drop packet
if line not up
Or
Send packet
but do not reset
Idle Timer

Figure 7-1 Outgoing Packet Filtering Process

Active Data
No
User-defined
match
Initiate call
Call Filters
if line not up
(if applicable)
Match
Drop packet
if line not up
Or
Send packet
but do not reset
Idle Timer
Send packet
and reset
Idle Timer
Filter Configuration