Wireless Access

Hey all, I have a customer who is in the middle of replacing their old Cisco WLAN with Aruba.  It's a fairly large hospital so the deployment needs to be done in phases, different wings, floor-by-floor.  

They have just deployed Aruba in the new wing, and they are seeing strange behavior with their Vocera badges.  When the caller and receiver are both on Aruba, there's no problem.  When they're both on Cisco, no problem.  But if the caller is on Aruba and the receiver is on Cisco, they sometimes (not always) lose half of the call - i.e. the person calls and the recipient answers, but they don't hear the voice.  Or the recipient can hear the caller, but the caller can't hear the recipient.

I'm wondering if anyone else has done a similar deployment, and if there are any recommendations to help minimize the impact during the transition?  I did find some older posts with broken links to design guides, but nothing helpful.  

The controller is running 6.3.1.1, and the Vocera badges are mostly B3000, with a few 2000 and 1000's that are being phased out.

Check a couple of things:

- make sure you all the lower data rates enabled under the SSID profile
- make sure that user-role has necessary ports and priorities for the Vocera traffic to flow properly
- enable WMM under the SSID profile
- confirm that your 802.11g environment is healthy (no interference ) show ap arm history ap-name

- Check if there's a lot of jitter and delay which may be cause by the RF environment or L1 issues :

show voice call-quality and do a voice trace while call is ongoing
- what are you using for encryption ?
- are using sharing the VLAN use by Vocera badges with other devices?
- how many SSIDs you have in place?

Hi Victor, thanks for the suggestions.   Everything that you have listed out is already enabled, and I don't think there's any issue with the Aruba wireless connection.  When the vocera badges are all on Aruba, there are no issues.  It's only when one device is on Aruba and one device is on the Cisco WLAN.

As to the rest of your questions:

- what are you using for encryption ?  

WPA2 AES / PSK

- are using sharing the VLAN use by Vocera badges with other devices?

No, the voice VLAN is exclusively for Vocera

- how many SSIDs you have in place?

5 in total.  

Anyway with that said, the customer has since rebooted their WISM and hasn't had any more reports of this issue, so I'm going to go ahead and blame Cisco :) I'm also going to push them to accellerate the Aruba deployment so they can get rid of the Cisco altogether and it won't be an issue anymore.

Hi Martin,

Thanks for all the details.    Your deployment is very similar to the one that I am troubleshooting.       For my customer, we have AP-225s running  a variation of release 6.3.1.1.     Upgrading the code to the current release  fixed a SFS problem, but it did not resolve the dropped conversations between the Aruba and Cisco WLANs.    I may ask them to reboot their WiSM.... :-)    The range long range goal to the convert the entire hospital to AP-225s.

Thanks,

--Kevin.

Hi Martin,

I am working on a similar problem in the states.      Can you tell me a little more about your deployment?

Questions:

1)   Is the Aruba and Cisco WLAN sharing the same subnet for the Vocera badges?

2)   Are you running WMM?    (I would be surprised, if you are.)

3)   What type of APs are deployed?

4)  What firmware are your badges running?

5)  Are the Cisco APs terminating on a WiSM?

Thanks,

--Kevin.

Hi Kevin, here's what they have:

1)   Is the Aruba and Cisco WLAN sharing the same subnet for the Vocera badges?

YES

2)   Are you running WMM?    

They have the voice wifi set to platinum service level on the wism and the others set to lower level,  other than some qos setup on the wirednetwork nothing else i can think of wirelessly

3)   What type of APs are deployed?  

(Cisco) 1141N, 1242AG, and 1231g  -- Aruba AP-105

4)  What firmware are your badges running?  

Vocera server is 4.3 build 2772, not sure about the firmware on the badges.

5)  Are the Cisco APs terminating on a WiSM?  

yes