Automatic Nat Detection; Udp Port Assignments - Mitel Inter-Tel 5000 Installation And Maintenance Manual

Automatic NAT Detection

Network Address Translation (NAT) is a method for translating internal IP addresses or network
addresses into public Internet addresses.
The Automatic Network Address Translation (NAT) Detection feature allows Inter-Tel IP
endpoints to operate inside or outside a private network NAT or firewall without having to
change the IP Settings\ NAT Address Type field every time the endpoint is relocated. The
feature enables Inter-Tel hard IP endpoints and the Inter-Tel Model 8602 IP softphone to place
and receive calls either from inside or outside an Inter-Tel private network.
Mitel 5000-series IP endpoints do not support the Automatic Network Address Translation (NAT)
address type. In DB Programming, you must select either Native or NAT for private and public
networks. Refer to the Inter-Tel 5000 Features and Programming Guide (part no. 580.8006) to
configure the NAT address type for Mitel 5000-series endpoints.
Automatic NAT Detection automatically determines whether an IP endpoint is inside the firewall
or outside the firewall. In DB Programming, the administrator designates each IP endpoint to
use the Auto type, as well as either Native or NAT types. The default selection is Auto.
Automatic NAT detection is performed each time an IP endpoint comes online and whenever
the feature is set through DB Programming.
This feature does not work with IP Gateways, IP trunks, Inter-Tel wireless Models 8664, 8665,
and 8668, any Inter-Tel IP endpoints in SIP mode and third-party SIP endpoints. Firmware on
these endpoints cannot run the Auto NAT Detection test. For these endpoints, the installer
needs to manually select the NAT Type setting.

UDP Port Assignments

Expanded IP endpoint capability with v2.0 and later requires changes in User Datagram
Protocol (UDP) port usage. If the Inter-Tel 5000 v2.x equipment operates inside a firewall and
services external IP endpoints, the firewall configuration needs to be updated to reflect the
changes in the UDP port assignments of system.
NOTICE
No-Audio Condition Possible. Failure to adjust the firewall UDP port settings to the
appropriate range can result in no-audio conditions for external IP endpoints, IP trunks, or IP
networking.
Tutorial
In DB Programming, the Audio Stream Receive Port defines the first of 33 even port numbers
that off-node IP resources use to transmit audio data to this IP resource. You must choose an
even-numbered value. The base audio port number, plus 64 additional port numbers, cannot
conflict with other port numbers on the IP connection.
For example, if the base audio port number is 5000, no other port numbers on the IP connection
can fall in the range from 5000 to 5064. Changing the Audio Stream Receive Port resets the IP
resources. The system broadcasts changes to an IP connection Audio Stream Receive Port to
the other nodes in the private network as a database update. This field corresponds to the off-
node IP connection Remote Audio Receive Port. To change the port number, enter the new
number in the text box, then press ENTER or click on another field. The default is 5004, and the
range of values is 1026–65468.
IMPORTANT
®
Inter-Tel 5000 Installation Manual – Issue 2.4, May 2008
Because SIP uses port 5060 (by default) for call control; firewalls, NATs, and
routers often treat this port as a "special case" and may block its use by non-
SIP packets. If your network currently uses SIP, Inter-Tel strongly
recommends that you use a different port range (other than 6004–7039) for
audio stream ports; otherwise, you may experience audio problems over the
IP network.
Chapter 4: Specifications
Automatic NAT Detection
Page 4-55