Filter Configuration - NETGEAR RH348 Reference Manual

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
Outgoing Data
packet filters
Drop
packet
Figure 8-1. Outgoing Packet Filtering Process

Filter Configuration

Figure 8-1.
No
match
Built-in
default call
filters
Match
Drop packet
if line not up
Filter Configuration
Call filters
No
match
User-defined
call filters
(if applicable)
Match Match
Drop packet
if line not up
Or
Send packet
but do not
reset idle timer
Chapter 8
No Active data
match
Initiate call
if line not up
Send packet
and reset
idle timer
Or
Send packet
but do not
reset idle timer
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8-1