Http; Dns; Nat - Avaya 4600 Series Administrator's Manual

Overview of Voice over IP (VoIP) and Network Protocols

HTTP

HTTP is potentially a more secure alternative to TFTP, particularly when Transport Layer
Security (TLS) is used to create HTTPS (Secure HTTP). You can store the same application
software, script file, and settings file on an HTTP server as you can on the TFTP server. With
proper administration, the telephone seeks out and uses that material appropriately. However,
the 4600 Series IP Telephone must already be running Release 2.2 software to be able to
access and use HTTP servers. As with TFTP, some functionality might be lost by a reset if the
HTTP server is not available. For more information, see
and HTTP on page 66.

DNS

The Domain Name System (DNS) is a distributed Internet directory service. DNS is used mostly
to translate between domain names and IP Addresses. Release 1.5 and later Avaya IP
Telephones can use DNS to resolve names into IP Addresses. In DHCP, TFTP, and HTTP files,
DNS names can be used wherever IP Addresses were available as long as a valid DNS server
is identified first. See

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 IP Telephones support NAT interworking. Therefore, no
problems exist with NAT and Release 1.7 of the 4600 Series IP Telephones. Note that support
for NAT does not imply support for Network Address Port Translation (NAPT). Specifically, the
4600 Series IP Telephones do not support communication to the PBX through any NAPT
device.
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
24 4600 Series IP Telephone Release 2.2 LAN Administrator Guide
DNS Addressing on page 84.
Related Documents
DHCP and File Servers
on page 15.
on page 47