topic VoIP over WLAN - Client Roaming Settings in Wireless

VoIP over WLAN - Client Roaming Settings

Frank Wagner — Sun, 04 Jul 2021 01:53:14 GMT

Hello,

what would you suggest, are the best settings in the "Client Roaming Section" of the WLC Configuration for the following requirements:

VoIP over WLAN deployment, 802.11a, WLC 4402, 25 - 30 access points (mainly 1252, a few 1130), 7925G phones.

In the moment the settings are set to default, that means: Min. Rssi = -85; Hysteresis = 3; Scan Tresh. = -72; Trans. Time = 5

Unfortunately we are not completely satisfied with the roaming behavior of our phones, so there is the question,

if the roaming behavior of the phones can be improved. Sometimes it looks like the phone takes too much time to make a roaming decision.

Thanks,

Greeting Frank

Re: VoIP over WLAN - Client Roaming Settings

Aaron — Thu, 17 Jun 2010 17:24:16 GMT

Frank, those settings only apply to Intel clients and are not used by 7925Gs. For the phones, I would recommend:

run the current firmware (1.3.4 SR1)
go through the 7925G Deployment Guide recommendations, chapter and verse (http://www.cisco.com/en/US/docs/voice_ip_comm/cuipph/7925g/7_0/english/deployment/guide/7925dply.pdf)

Aaron

Re: VoIP over WLAN - Client Roaming Settings

Frank Wagner — Fri, 18 Jun 2010 07:04:04 GMT

Hello Aaron,

thanks for your answer.

The phones are already running on firmware 1.3.4 SR1.

And meanwhile, I think I know the 7925G Deployment Guide by heart.

But sometimes the phone simply makes the wrong roaming decision.

Unfortunately it's not 1 out of hundred, it's one out of 10 decisions that's wrong.

Maybe it would be a suggestive feature in the future if one can set "default roaming routes" for the phone.

Greetings Frank

Re: VoIP over WLAN - Client Roaming Settings

Elliott Shawd — Sat, 19 Jun 2010 05:10:07 GMT

So your wireless network was properly surveyed for and channel/power settings for aps are configured properly? Do you have your WLAN set up for CCKM and WMM? Do you have qos set up for voice?

Re: VoIP over WLAN - Client Roaming Settings

Frank Wagner — Mon, 21 Jun 2010 07:48:58 GMT

Our wireless wireless network has been surveyed twice.

The first time to figure out the positions of the Access Points and because there have been changes in amount of APs

and position of some APs, a second time to figure out the ideal power level and channel settings for the changed environment.

The amount of APs and some positions changed, because sometimes there have been two APs in the same office

with an RSSI, let's say 60-65 and the phone was permanently changing the AP, what impacted the quality of the phone call.

The WMM and QOS settings are set for the WLAN, as described in the 7925G Deployment Guide.

CCKM is not set, because we are using WPA2-PSK.

Isn't CCKM of note only, when using 802.1x authentication?

Greetings Frank

Re: VoIP over WLAN - Client Roaming Settings

Aaron — Tue, 22 Jun 2010 02:54:38 GMT

Frank, what version of code are you running on the WLCs/APs? If 6.0.182.0 thru 6.0.196.0,then do please note that the APs are susceptible to:

CSCta29484: Radio stops beaconing for 10-second period (fixed in 6.0.196.0)

CSCte89891 Radio may stop transmitting beacons periodically (affects 6.0.196.0 too)

If the phone doesn't receive beacons for one second, it'll roam to another AP.

Aaron

Re: VoIP over WLAN - Client Roaming Settings

Frank Wagner — Tue, 22 Jun 2010 06:22:36 GMT

Hello,

we are running the 7.0.98 code.

Greetings, Frank

Re: VoIP over WLAN - Client Roaming Settings

Aaron — Tue, 22 Jun 2010 15:04:51 GMT

7.0.98.0 is not susceptible to those known beaconing problems.

I would recommend opening a TAC case, and being prepared to collect multichannel, NTP-sychronized wireless packet traces, coordinated with phone traces, WLC/AP debugs, and wired packet traces.

Aaron

Re: VoIP over WLAN - Client Roaming Settings

Frank Wagner — Wed, 23 Jun 2010 07:21:37 GMT

Thanks Aaron.

We will definitely consider this possibility.

Re: VoIP over WLAN - Client Roaming Settings

Dominic Stalder (old profile) — Thu, 22 Jul 2010 07:49:50 GMT

Hi Frank

have you been able to solve your problems. We have the same issues with 7921 (1.3.4SR1) and 7.0.98.0, but we are not able to solve the problems.

Regards

Dominic

Re: VoIP over WLAN - Client Roaming Settings

Frank Wagner — Thu, 29 Jul 2010 07:49:51 GMT

Hello Dominic,

at the moment we are redesigning the problematic spots in our network

and this will hopefully help to resolve our problems.

Greetings Frank

Re: VoIP over WLAN - Client Roaming Settings

Dominic Stalder (old profile) — Thu, 29 Jul 2010 07:54:11 GMT

Hi Frank

thanks for the feedback. Actually we are working with the TAC and hopefully we gonna have a solution today or tomorrow.

As soon as I now more I will post it here.

Regards

Dominic

Re: VoIP over WLAN - Client Roaming Settings

Frank Wagner — Wed, 04 Aug 2010 10:56:02 GMT

Hello Dominic,

Did you get your problems solved in the meantime?

Greetings Frank

Re: VoIP over WLAN - Client Roaming Settings

Dominic Stalder (old profile) — Wed, 04 Aug 2010 14:47:11 GMT

Hi Frank

no not at all, we are working with the TAC since 2 weeks and with the business unit (developers) voice and wireless since 2 days, but actually we do not have a solution.

Regards

Dominic

Re: VoIP over WLAN - Client Roaming Settings

Dominic Stalder (old profile) — Sun, 29 Aug 2010 14:42:02 GMT

Hi Frank

how are you doing with your VoIP design? We also redesigned some spots, but we still have voice gaps and it is annoying.

Regards

Dominic

Re: VoIP over WLAN - Client Roaming Settings

Frank Wagner — Mon, 30 Aug 2010 07:47:54 GMT

Hello Dominic

In the meantime, we decided to request for help at another distributor.

They sent their wifi specialist and after one day of testing he was sure,

that this isn't a problem of a wrong configuration or missing coverage or something else,

but it's a failure of one of the components in the wifi network.

Therefore he opened a cisco TAC case and meanwhile cisco is analyzing several debug logs and protocols.

According to the statement of the wifi specialist, cisco should be able to find the failure this week.

We will see......

Greetings Frank

Re: VoIP over WLAN - Client Roaming Settings

Dominic Stalder (old profile) — Mon, 30 Aug 2010 08:15:59 GMT

Hi Frank

thanks for your feedback, exactly the same process as we are running through.

We arranged a site survey with another wireless specialist (third opinion) and the specialist is also sure, that this can not be a design (configuration or coverage) problem. You can stand next to an access point but the phone will not roam to it in the first 20 - 30 seconds, only after this time the phone can see the access point and roams to it.

It would be nice, if you send me the feedback of Cisco, maybe this would help to force our case. Do you have a case opened at Cisco?

Best regards

Dominic

Re: VoIP over WLAN - Client Roaming Settings

Frank Wagner — Mon, 30 Aug 2010 09:53:20 GMT

Hello Dominic,

if you wish, you can contact me directly by email (f.wagner AT lissmac.com),

i'll send you my contact information and we could exchange information via phone.

Greetings Frank

Re: VoIP over WLAN - Client Roaming Settings

Dominic Stalder (old profile) — Mon, 30 Aug 2010 19:03:28 GMT

Hi Frank

thanks a lot for your contact information. I will send you a mail or will call you as soon as possible. We got a great message today, there are two Cisco engineers (business unit) comming onsite this week and I hope we are going to solve our problems!

As soon as I know more, I will contact you. But as a hint, if I forget it (this happens a lot at the moment ;-)) just reply to this post and I will contact you.

Regards

Dominic

Re: VoIP over WLAN - Client Roaming Settings

lus — Wed, 01 Sep 2010 11:35:23 GMT

Hello

Same problem here. Bad roaming issues with the 7925 Phone.

Regards