Implementing VoIP on a Flexconnect solution

[aleopoldie]

Hello experts,

Is that a problem to deploy VoIP on a flexconnect network ? I mean, is there a roaming problem is clients are roaming from 1 flexconnect AP to another flexconnect AP while the WLC is centralized on the HQ ?

Reading the following, it is advised to deploy a local WLC on each branch location ...

WPA2—To improve client roam times, WPA2 introduced key caching capabilities, based on the
IEEE 802.11i specification. Cisco created an extension to this specification called Proactive Key
Caching (PKC). PKC today is supported only by the Microsoft Zero Config Wireless supplicant and
the Funk (Juniper) Odyssey client. Cisco CCKM is also compatible with WPA2.
Remote branch locations requiring predictable, fast roaming behavior in support of applications
such as wireless IP telephony should consider deploying a local WLC (Virtual Controller on UCS
blade or 2500 WLC).

AL

[Benoit Loriaux]

I have it implemented all over the place. (Even in remote location where annexes part of the buildings are connecting back to the core switch via a wireless shot because there were no service provider options avilable, and it works all good when they are connecting back to the DC)

To give you an idea of the path.

WLC at the DC <=> Internet provider <=> remote site core <=> wireless shot (using cheap non Cisco gears)<=> access switch <=> flexconnect AP <=> VoWLAN client.


This is all because VoWLAN don't need a lot of bandwidth but good latency.

So you want 802.11r (fast roaming)

And CCKM will help for sure.

PLEASE ! Do not forget to sort your Felxconnect AP group otherwise none of this is going to be a successful implementation. You want to have the APs of that building or floor in the same flex-connect group 

I assume you've got the QoS implemented properly.

Review you AP coverage and disable low data rates, if you need more information about this do not hesitate to ask !

[aleopoldie]

Thank you for this detailed answer Benoit !

And your client traffic, including voice is going back to the WLC everytime a client wants to calls another client ? Or do I have to configure The Split Tunneling ?

The goal would be to avoid the traffic to go back to the WLC, and through the WAN link everytime a client in a branch site A wants to talk with another client in the branch site A 

Thank you,

AL

[aleopoldie]

Hello Benoit,

I read on the following document that roaming with local authentication can have some problems if there is no WLC locally installed on branch sites 

"WPA2—To improve client roam times, WPA2 introduced key caching capabilities, based on the
IEEE 802.11i specification. Cisco created an extension to this specification called Proactive Key
Caching (PKC). PKC today is supported only by the Microsoft Zero Config Wireless supplicant and
the Funk (Juniper) Odyssey client. Cisco CCKM is also compatible with WPA2.
Remote branch locations requiring predictable, fast roaming behavior in support of applications
such as wireless IP telephony should consider deploying a local WLC (Virtual Controller on UCS
blade or 2500 WLC)."

Are you using localswitching ? Is it working ?

Thank you,

AL