VoIP over WLAN - Client Roaming Settings

[Frank Wagner]

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

[Dominic Stalder (old profile)]

Hi

yes indeed, Javier - the developer of the WLC Analyzer - was onsite, so we used the analyzer as a troubleshooting helper ;-)

Regards

Dominic

[Frank Wagner]

Hello Dominic,

I've just read in the forum, that a new 7.x code called 7.0.98.205 (an Engineering Special build) is available through TAC.

I was wondering if you have already updated your WLC or if your are going to update the next time.

Because according to the release notes (you find them in the "Other Wireless" section of the forum)

they have fixed one of the three bugs (CSCtg74904) you have posted a few weeks ago, after the visit of the cisco engineer.

Greetings Frank

[Dominic Stalder (old profile)]

Hi Frank

we did an upgrade to 7.0.98.202, but not yet to 7.0.98.205. I will just write our TAC engineer, thanks a lot for the hint.

Regards

Dominic

[Frank Wagner]

Hello Dominic,

has the "202" release already included the described bug?

Have you noticed any improvements concerning your problems with that "202" release?

Greetings Frank

[Dominic Stalder (old profile)]

Hi Frank

no the .202 version did not include any solution for our debugs, was just a "nice to have" upgrade.

Regards

Dominic

[guilhem.perez]

Hi,

I'm in the same context like you (WLC 5508 v7.0.98.0, AP 1142N, IP PHONE 7921 v1.3.4SR1) and we meet VoIP over WLAN issue.

Did you try 7.0.98.205 build?

Does this buld improve client roaming issue and others issues?

Could you send me this buld please?

Thank you.

Best regards

Guilhem PEREZ

[Dominic Stalder (old profile)]

Hi Frank

sorry I gave you wrong information. I just had contact with the Cisco Engineer of the Business unit and he told me this one:

CSCtg74904 was first added into 7.0.98.202, 205 is just an accumulative release, that also has that bug, plus other changes. So, if the reason to upgrade to 205 is that bug id, you already got that fix, since I did the onsite visit.
  
AS relevant that may affect your deployment, and that are added to 205:

CSCti91944 Unified APs removing clients on max-retries.                                                     
If the phone goes out of RF coverage, and the AP sends 255 TX tries, with this fix, the phone is not removed, but moved to inactive state.
If you have RF areas where you can hit 255 failed transmit events (which is not same as retries..), then RF needs tuning, but this would prevent phone to be removed.

CSCtg41911 Radio may stop transmitting for several seconds due to MSDU packet load
CSCti06835  Multicast packets stuck on radio forever, after WLAN changes
These two are mostly on multicast and 11n deployments. The phones are 11a/g, so not direct critical.

Hope this answers your last question about the bug CSCtg74904.

Regards

Dominic

[Dominic Stalder (old profile)]

Hi Guilhem

we did not upgrade to 7.0.98.205, so I am sorry, I do not have this software build.

No the .205 release will not solve any client roaming issues, because the biggest part of roaming decisions is in the phone load. I noted some bugfixes in the post before, maybe this helps you.

On our site we had to install more access points, because Cisco did not (yet) develop a new firmware for this pico cell environment.

Regards

Dominic

[Frank Wagner]

Hello Dominic,

thanks for your detailed response.

I will talk to my distributor, if the new firmware is interesting for us or if we wait for the next official release.

By the way, as you seem to have a really "hot" connection to Cisco,

have you got any news, when they plan to release a new official firmware for WLC, or even more important, for the 7925?

Greetings Frank

[Dominic Stalder (old profile)]

Hi Frank

as you know Cisco too, they are not willing to release any dates if they are not officially fixed and published ;-)

In a presentation in June this year, there was the following release planned: Release 7.0MR1 for November 2010.

About the phone load I know that they are working on 1.4.x, but don't know when this is going to be released.

Regards

Dominic

[Wilson Samuel]

Hi All,

It seems that we also have exactly the same issues.

7925s wont roam properly, and WLC is 5508 with 7.0.98.0 and a lot of 7925s.

Anyone got a conclusion of this isse yet?

Sam Wilson

[Frank Wagner]

Hello folks,

there's a new phone firmware 1.4.1 available at the Cisco Homepage.

According to the release notes, they didn't solve the bugs mentioned in this thread.

I will download and test it anyway......

Greetings Frank

[Dominic Stalder (old profile)]

Hi Frank

thanks for the information. Yes they told us, that there will no bugs (found at our problem) be solved in this version.

It is not sure, if they ever gonna solve theses bugs.

Hope you are doing well with the tests anyway.

Regards

Dominic

[etmarcof]

Hi,

Have you tested firmware 1.4.1? Could you Give me some feedback?

Because now i am using 1.3.3 but i have some roaming problems.

Best Regards

MC

[Dominic Stalder (old profile)]

Hi MC

as far as I know - and we tested it last week - there are no (big) changes concerning the roaming algorithms and so we didn't see any improvement in our pico cell environment. But you can test it for your environment.

Regards

Dominic