Figure 211 H.323 With Multiple Wan Ip Addresses; Figure 212 H.323 Calls From The Wan With Multiple Outgoing Calls - ZyXEL Communications ZYWALL P1 User Manual

With multiple WAN IP addresses on the ZyWALL, you can configure different firewall
and NAT Many One to One rules to allow incoming calls from each WAN IP address to
go to a specific IP address on the LAN. Use NAT Many One to One address mapping to
have the H.323 calls from each of those LAN IP addresses go out through the same WAN
IP address that calls come in on. The NAT Many One to One address mapping lets the
ZyWALL correctly forward the return traffic for the calls initiated from the LAN IP
addresses.
For example, you configure firewall and NAT Many One to One rules to allow LAN IP
address A to receive calls through public WAN IP address 1. You configure different
firewall and NAT Many One to One rules to allow LAN IP address B to receive calls
through public WAN IP address 2. You configure corresponding NAT Many One to One
address mapping to have calls from LAN IP address A go out through WAN IP address 1
and calls from LAN IP address B go out through WAN IP address 2.

Figure 211 H.323 with Multiple WAN IP Addresses

• When you configure the firewall and NAT Many One to One address mapping to allow
calls from the WAN to a specific IP address on the LAN, you can also use NAT Many
One to One address mapping to have H.323 calls from other LAN IP addresses go out
through a different WAN IP address. The NAT address mapping lets the ZyWALL
correctly forward the return traffic for the calls initiated from the LAN IP addresses.
For example, you configure the firewall and NAT Many One to One address mapping to
allow LAN IP address A to receive calls from the Internet through WAN IP address 1.
You also use NAT Many One to One address mapping to have LAN IP address A make
calls out through WAN IP address 1. Configure another NAT Many One to One address
mapping entry to have H.323 calls from LAN IP addresses B and C go out through WAN
IP address 2. Even though only LAN IP address A can receive incoming calls from the
Internet, LAN IP addresses B and C can still make calls out to the Internet.

Figure 212 H.323 Calls from the WAN with Multiple Outgoing Calls

• The H.323 ALG operates on TCP packets with a port 1720 destination.
• The ZyWALL allows H.323 audio connections.
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