Why use "tunnel mode"

[bob_williamson]

There is an option in the WLAN settings that states "Tunnel WLAN traffic to ZoneDirector (Recommended for VoIP clients and PDA devices.)"

From what I understand it forces all traffic through an L2TP, which to me seems like it would introduce some latency.

If so, why does it say recommended for "VOIP and PDA devices"?

Thanks,
Bob

[bob_williamson]

Agreed, seems weird to me as well. The one time I used it was when I installed a new switch and did not setup the necessary vlan tags on the ports (we have different vlans for different SSIDs). Worked great for that.

I think from his explanation the inter-subnet roaming is the most important.

Bob

[jelle_alten_606]

There is a nice side effect: I have a ZD at my office that also controls AP's on different sites. I made one hidden SSID named "tunnel" that and have that one tunnel to the ZD. Whenever I connect to that wlan, it is as if I have a VPN connection to my office.
I turned on the encryption for tunneling, of course. So every AP can VPN bridge to the ZD, but on a lower level than normal VPN bridges. The ip ranges don't even need to be different, because it is tunneling on a lower level. Nice.

[DarrelRhodes]

Tunnelling traffic has multiple applications. With VoIP (not necessarily Wi-Fi calling, which is a related but a very different beast), tunnelling the traffic can prevent prevent delay-sensitive traffic from being adversely affected by local network conditions which may impact latency. 

We have a knowledge base article with more information here: https://support.ruckuswireless.com/articles/000002896

And a full document for download here: https://support.ruckuswireless.com/documents/2339-smartzone-voice-over-ip-voip-best-practices-design...