NAT

A Network Address Translation (NAT) is an application that can be administered between your network and the Internet. The NAT translates network layer IP Addresses so your local intranet IP Addresses can duplicate global, Internet addresses. A detailed discussion of NAT is beyond the scope of this document. Note that NAT use can lead to problems that affect the consistency of addressing throughout your network. In Release 1.6 and earlier releases of the 4600 Series IP Telephones, NAT is not recommended for networks handling IP-based telephony traffic. As of Release 1.7, all 4600 Series H.323 IP Telephones support NAT interworking. Therefore, no problems exist with NAT and these H.323 IP telephones. Note that support for NAT does not imply support for Network Address Port Translation (NAPT). Specifically, the H.323 IP telephones do not support communication to the PBX through any NAPT device. SIP IP telephones do not support NAT.

NAT requires specific administration on the media server. The capability to have a direct Avaya IP Telephone-to-Avaya IP Telephone call with NAT, also called “NAT shuffling,” requires Avaya Communication Manager Release 1.3 software. See the Administration for Network Connectivity document listed in Related Documents.