User guide

Chapter 24: Network Configuration Guidelines for VoIP
292 MAXCS ACC 6.7.1 Administration Manual
Configuration Guidelines for NAT
Note: This section only applies to AltiGen IP phones or IPTalk integrated with
MaxCommunicator or MaxAgent.
The section discusses the configuration guidelines when AltiServ is behind NAT (Network
Address Translation) and communication to AltiGen IP phones, IPTalk, or another
AltiServ is over WAN. AltiGen SIP phones support NAT traversal, which does not require
special settings on the NAT router at the remote site.
Due to H.323/SIP protocol, which puts the IP address information in the TCP/IP payload,
the NAT router requires some H.323 protocol and SIP protocol implementation to cor-
rectly handle the H.323/SIP traffic and translate the private IP address into a public IP
address. Not all NAT routers have this kind of implementation. If the NAT router does
not support H.323/SIP, you need to check Enable SIP NAT support and Enable H323
NAT support in Enterprise Manager, IP Networks tab.
The following sections illustrate a private network configuration and a VPN configuration.
For information on setting up VoIP traffic forwarding for NAT and configuring AltiServ
behind NAT, see “Configuring AltiServ Behind NAT” on page 310.
Private Network Configuration Example
(MAXCS with private IP address and behind NAT)
Only the private IP address is used in a private network—the public router will not route
the packet that has a private IP address as its destination. (All IP addresses beginning
with 192.168.x.x, 10.x.x.x, or 172.16.x.x to 172.32.x.x are private IP addresses.)
Figure 137. MAXCS behind NAT