NETGEAR RH348 Filter Configuration, Chapter

Chapter 8

Filter Configuration

This chapter provides information about using filters and configuring filters for your

Model RT328/RH348 router.

The router uses filters to decide whether to allow passage of a data packet and/or to make a call

over the ISDN line. Three types of filters are involved: incoming data filters, outgoing data filters, and call filters. Data filters screen the data to determine if the packet should be allowed to pass. Call filters are used to determine if a call should be placed.

Outgoing packets must pass through the data filters before they encounter call filters. The call filters are divided into two groups: default call filters and user-defined call filters. The Model RT328/RH348 router has default call filters that filter out administrative packets (for example, RIP packets). The router applies the default filters first and then, if applicable, applies the user-defined call filters as shown in Figure 8-1.

Call filters

No

No

No

Active data

Outgoing

Data

match

Built-in

match User-defined

match

Initiate call

packet

filters

default call

call filters

if line not up

filters

(if applicable)

Send packet

and reset

Match

Match

Match

idle timer

Drop

Drop packet

Drop packet

packet

if line not up

if line not up

Or

Or

Send packet

Send packet

but do not

but do not

reset idle timer

reset idle timer

Figure 8-1.

Outgoing Packet Filtering Process

7787EA

Filter Configuration

8-1