Filter configuration, Introduction to filters, Chapter 30 filter configuration – ZyXEL Communications P-334W User Manual
Page 357: 1 introduction to filters

Prestige 334W User’s Guide
Filter Configuration
30-1
Chapter 30
Filter Configuration
This chapter shows you how to create and apply filters.
30.1 Introduction to Filters
Your Prestige uses filters to decide whether to allow passage of a data packet and/or to make a call. There are
two types of filter applications: data filtering and call filtering. Filters are subdivided into device and protocol
filters, which are discussed later.
Data filtering screens the data to determine if the packet should be 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 should
be 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 the following
figure.