ZyXEL Communications 802.11g Wireless ADSL2+ 4-port VoIP IAD P-2602HWNLI - Manual (Page 428)

P-2602HWNLI User’s Guide
428 Appendix I Commands
Data filtering screens 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 Ethernet side. Call filtering
is used to determine if a packet should be allowed to trigger a call.
Outgoing packets must undergo data filtering before they encounter call filtering. Call filters
are divided into two groups, the built-in call filters and user-defined call filters. Your ZyXEL
Device has built-in call filters that prevent administrative, for example, RIP packets from
triggering calls. These filters are always enabled and not accessible to you. Your ZyXEL
Device applies the built-in filters first and then the user-defined call filters, if applicable, as
shown next.
Figure 226 Outgoing Packet Filtering Process
Two sets of factory filter rules have been configured to prevent NetBIOS traffic from
triggering calls. A summary of their filter rules is shown in the figures that follow.
The following figure illustrates the logic flow when executing a filter rule.
Data
Filtering Outgoing
Packet
Drop
packet
Built-in
default
Call Filters
User-defined
Call Filters
(if applicable)
Initiate call
if line not up
Active Data
Send packet
and reset
Idle Tim er
Or Or
Drop packet
if line not up Drop packet
if line not up
Send packet
but do not reset
Idle Tim er
Send packet
but do not reset
Idle Tim er
M atch M atch M atch
No
m atch
No
m atch No
m atch
Call Filtering