ZyXEL Communications ZyWall USG 2000 User Manual page 296

Chapter 18 ALG
can receive incoming calls from the Internet, LAN IP addresses B and C can still
make calls out to the Internet.
Figure 187 VoIP Calls from the WAN with Multiple Outgoing Calls
VoIP with Multiple WAN IP Addresses
With multiple WAN IP addresses on the ZyWALL, you can configure different
firewall and virtual server (port forwarding) rules to allow incoming calls from
each WAN IP address to go to a specific IP address on the LAN (or DMZ). Use
policy routing to have the H.323 (or SIP) calls from each of those LAN or DMZ IP
addresses go out through the same WAN IP address that calls come in on. The
policy routing lets the ZyWALL correctly forward the return traffic for the calls
initiated from the LAN IP addresses.
For example, you configure firewall and virtual server rules to allow LAN IP
address A to receive calls through public WAN IP address 1. You configure
different firewall and port forwarding rules to allow LAN IP address B to receive
calls through public WAN IP address 2. You configure corresponding policy routes
to have calls from LAN IP address A go out through WAN IP address
from LAN IP address B go out through WAN IP address 2.
Figure 188 VoIP with Multiple WAN IP Addresses
Finding Out More
• See Section 5.4.21 on page 99
• See Section 6.7 on page 125
to-peer H.323 traffic.
• See Section 18.3 on page 299
296
for related information on these screens.
for a tutorial showing how to use the ALG for peer-
for ALG background/technical information.
ZyWALL USG 2000 User's Guide
and calls
1