Nat Traversal Feature; Network Configurations - Nortel NN43001-504 Installation Manual

84 System information

NAT Traversal feature

The NAT Traversal feature is used where the IP Phone (this includes the
handsets) is located on the private side of the NAT router, while the rest of
the Server resides on the public side.
To ensure correct deployment of the wireless handsets in this type of
network configuration, most, if not all, of the WLAN equipment must reside
on the private side of the NAT router.
Network configurations
The WLAN Handset 2212 has a VPN feature that enables an IPsec tunnel
to a Nortel VPN Router, which is the only IPsec platform supported today.
This feature alters some of the usual design recommendations for the
telephony components, such as the WLAN IP Telephony Manager 2245.
Usually, the WLAN IP Telephony Manager 2245 is placed in the same
subnet with the handsets.
With the VPN feature enabled, the WLAN IP Telephony Manager 2245 now
resides behind the VPN Router in a different subnet from the handsets;
however, even though the same-subnet restriction has been lifted, it is still
very important to locate the WLAN IP Telephony Manager 2245 as close to
the handsets as possible. In this case, it is located immediately behind the
VPN Router (and in the same subnet as the VPN Router). The VPN Router
must also be located as close to the handsets as possible.
You can deploy the handsets behind a NAT router with no Security Switch,
as shown in
configuration includes a Layer 2 switch, which can be any Layer 2 switch
(for example, Nortel Ethernet Switch 450). No Layer 3 device, such as a
router, can be located between the wireless handsets and the WLAN IP
Telephony Manager 2245.
Copyright © 2004-2007, Nortel Networks
.
Figure 18 "VPN design over a Layer 2 network" (page
Nortel Communication Server 1000
WLAN IP Telephony Installation and Commissioning
NN43001-504 01.02 Standard
Release 5.0 15 June 2007
85). This