L3 Roaming

RUCKUS vSZ and vSZ-D/SZ100-D architecture now supports L3 Roaming without the need for additional mobility controllers.

The key use cases for L3 Roaming are well-understood,. Typically, a large WLAN network where APs are separated on different VLAN segments and there is a need for IP address preservation and potentially session persistence. Most common deployments are large campus networks designed with multiple switches and VLANs and there is a need to support L3 Roaming.

On vSZ-D/SZ100-D, RUCKUS Wi-Fi can now support L3 Roaming with IP Address preservation. Below is the high level use case that describes the feature functions. A large network that is broken up into various campuses and there is a need to support L3 Roaming. Below figure depicts 2 campuses, which are L2 separated but need L3 Roaming.

The APs in campus A setup a tunneled WLAN to the vSZ-D (Using Zone Affinity) and APs in building B setup a tunneled WLAN to the vSZ-D in their building.

Each vSZ-D/SZ100-D in the building can be configured to run a DHCP Server and NAT the traffic or be setup as a DHCP Relay. When a client roams from an AP in building A to an AP in building B, the vSZ-D/SZ100-D in building B detects the roaming event and forwards the traffic (or assigns the same IP back to the client) to the vSZ-D in building A (home vSZ-D/SZ100-D or anchor vSZ-D/SZ100-D) to ensure that service to the client is not interrupted.

One additional unique benefit of this architecture over other L3 Roaming solutions is that with this architecture, the roamer client can still have access to his home network resources (this is similar to mobile roaming on 3G/4G networks).
Note: Traffic between inter vSZ-D/SZ100-D tunnels in Figure 6 can be encrypted by enabling tunnel encryption. Refer to Enabling Tunnel Encryption for more information.
Figure 1. Usage of L3 roaming