ZyXEL Communications P-2301R/RL-P1C Support Notes page 20

device category; they act on the raw data from/to LAN and WAN. The IP and IPX filter rules belong to the
protocol category; they act on the IP and IPX packets.
In order to allow users to specify the local network IP address and port number in the filter rules with SUA
connections, the TCP/IP filter function has to be executed before SUA for WAN outgoing packets and after the
SUA for WAN incoming IP packets. But at the same time, the Generic filter rules must be applied at the point
when the ZyXEL device is receiving and sending the packets; i.e. the ISDN interface. So, the execution
sequence has to be changed. The logic flow of the filter is shown in Figure 1 and the sequence of the logic flow
for the packet from LAN to WAN is:
•
LAN device and protocol input filter sets.
•
WAN protocol call and output filter sets.
•
If SUA is enabled, SUA converts the source IP address from 192.168.1.33 to 203.205.115.6 and
port number from 1023 to 4034.
•
WAN device output and call filter sets.
The sequence of the logic flow for the packet from WAN to LAN is:
•
WAN device input filter sets.
• If SUA is enabled, SUA converts the destination IP address from 203.205.115.6 to 92.168.1.33 and port
number from 4034 to 1023.
• WAN protocol input filter sets.
•
LAN device and protocol output filter sets.
All contents Copyright (c) 2007 ZyXEL Communications Corporation.
Prestige 2301R/RL-P1C Support Notes
20