Nortel Networks NN43001-504 - Manual (Page 87)

NAT 87
DHCP assignments, the routing requirements on the VPN Router become
much more complicated. To support such a scenario, you must configure
static routes on the public interface as well as inject those routes into the
routing protocol on the private interface. Therefore, Nortel recommends that
you do not use the network design shown in
Figure 20 "Not recommended
VoWLAN design" (page 87) as a design for the VPN feature.
Figure 20
Not recommended VoWLAN design
If you deploy the VPN feature of the WLAN Handset 2212 in a mixed
network where WLAN Handsets 2211/2210s are also in use, the design
recommendation becomes a little more complex. If you place a WLAN IP
Telephony Manager in the subnet with the WLAN Handsets 2210/2211, and
place a WLAN IP Telephony Manager in the subnet with the VPN Router
to support the WLAN Handset 2212, admission control problems for the
telephony WLAN can occur. Each WLAN IP Telephony Manager counts the
number of their own devices placing calls over APs, but does not count the
number of calls controlled by the other WLAN IP Telephony Manager. This
creates a blind spot for each device, and it is possible to oversubscribe an
AP by up to 2:1. The best solution to this problem is to have the WLAN
Nortel Communication Server 1000
WLAN IP Telephony Installation and Commissioning
NN43001-504 01.02 Standard
Release 5.0 15 June 2007
Copyright © 2004-2007, Nortel Networks
.