Prestige 201 ISDN Access Router

Outgoing

Packet

Data Filtering

Match

No match

 

 

Call Filtering

 

 

 

Built-in

No

User-defined

No

match

match

default

 

Call Filters

 

Call Filters

 

(if applicable)

 

 

Match

 

 

Match

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Active Data

Initiate call if line not up

Send packet and reset Idle Timer

Drop packet

Drop packet

 

 

 

Drop packet

 

 

 

if line not up

 

 

 

if line not up

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Or

 

 

 

 

 

Or

 

 

 

 

 

 

Send packet

 

 

 

 

Send packet

 

 

 

 

 

 

 

 

 

 

but do not reset

 

 

but do not reset

 

 

 

 

 

Idle Timer

 

 

 

Idle Timer

 

 

 

 

 

 

 

 

 

 

 

 

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.

6-2

Filter Configuration

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ZyXEL Communications P-202 manual Outgoing Packet Filtering Process, Filter Structure of the Prestige