Nortel Networks MOG7xx, MOG6xx Access Point, Mobility across different subnets when using DHCP

38

Mobility across different subnets when using DHCP

If a WSS is not in use, and the IP address of the wireless handset has been acquired through DHCP, the wireless handset must be powered down and powered up when entering a new subnet. This enables functionality of the wireless handset when entering the WLAN RF signal coverage area of a different WLAN IP Telephony Manager 2245 group on a different subnet. Normal functionality returns once the wireless handset:

•establishes communication within the Extended Service Set ID (ESSID) of the new WLAN

•obtains another IP address from the DHCP Server

•checks in with the group master

If the wireless handset is configured to use the ESSID of the new WLAN, it automatically discovers the ESSID of the APs operating in broadcast mode.

Table 2 summarizes the roaming and handover capabilities.

Table 2 Roaming and handover capabilities summary

IP address	WSS in use	Roaming capability	Handover capability
Static	No	No	No
Static	Yes	Yes	Yes
DHCP	No	Yes, if the wireless	No
		handset is
		power-cycled between
		subnets.
DHCP	Yes	Yes	Yes

Access Point

The 802.11b APs provide the connection between the wired Ethernet LAN and the wireless (802.11) LAN. APs work in all markets and must be positioned in all areas where the WLAN handsets are used. The number and placement of APs affects the coverage area and capacity of the WLAN IP Telephony system. Typically, the requirements for use of WLAN Handsets 2210/2211 are similar to those of other wireless data devices.

The APs must be SVP-compliant to support QoS. For a list of supported APs, refer to Appendix A: Compatible Access Points on page 77.

When a user on an active call is moving about, the call switches from one AP to another in the subnet. This changeover is transparent to the user.

Overview