Chapter 11 Filter Configuration; Introduction To Filters - Nortel 222 User Manual

Chapter 11
Filter configuration
This chapter shows you how to create and apply filters.

Introduction to filters

Your Business Secure Router uses filters to decide whether to allow passage of a
data packet, make a call, or both. There are two types of filter applications: data
filtering and call filtering. Filters are subdivided into device and protocol filters.
Data filtering screens the data to determine if the packet is allowed to pass. Data
filters are divided into incoming and outgoing filters, depending on the direction
of the packet relative to a port. Data filtering can be applied on either the WAN
side or the LAN side. Call filtering is used to determine if a packet is allowed to
trigger a call. Remote node call filtering is only applicable when using PPPoE
encapsulation. Outgoing packets must undergo data filtering before they
encounter call filtering as shown in Figure
Nortel Business Secure Router 222 Configuration — Advanced
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