Maximum latency between anchor/remote guest controllers?

Unanswered Question
Sep 13th, 2010

Hi all,

We have a scenario where I need to provide guest services to users at a remote site that only has a Satellite connection with latency up around 800ms.

If i run a remote controller on that site and tunnel guest traffic back to a central guest anchor controller over the sat link with that latency affect the ability of the controllers to work in any way?

I know REAP has latency limits, just wondering about the latency between controllers?

Thanks again,

Rob

I have this problem too.
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Sharath Kattema... Mon, 09/13/2010 - 23:00

Hi Rob ,

I believe the latency limit comes  when we are using  HREAP kind of deployment  .

However there should not be any problem at all when we tunnel the traffic to the guest tunnel anchor controller  when the AP are working in local mode. The 100 msec latency limit is not applicable when using controller mobiliy tunneling

A lot depends upon whether you are doing guest tunnelling with webauth or 802.1x auth over the tunnel.

If you are doing 802.1x, you are subject to eap timers since authentication occurs on the anchor.  Otherwise, there should be no problem.

Regards ,

Sharath K.P.

robporzig Mon, 09/13/2010 - 23:14

Hi Sharath,

Thanks for your response.

At this stage we will only be supplying guest WLAN's, so all traffic would be tunnelled back to the anchor controller over the Satellite. AP's will be in local mode and authentication of the guest clients will be done using web auth.

As this is the case from what you;re saying we should be fine, as long as we dont add another secure WLAN which has 802.1x authentication back over the Sat?

Cheers,

Rob

Sharath Kattema... Mon, 09/13/2010 - 23:25

Hi Rob ,

Yes i did search for any know issue reported  regarding latency limitation for Guest tunelling ,didnt find  any .

802.1 x has some specific EAP times depending on the authentication we are using right , they should be taken care .

We can check the same through controller , if you have configured through

eap authentication timers on the controller (show adv eap)...and authentication timers with radius server




Regards ,
Sharath K.P.
bbxie Tue, 09/14/2010 - 16:18

Hi Sharath,

I'm also not quite sure about what's the latency/bandwidth/mtu etc requirements between different WLAN components especially when these components are seperated through WAN link, could you pls. help on it? Thanks!

There are 7 kind of scenarios:

1. Between HREAP and WLC: (this is the only scenario I can find the requirements from Cisco doc)

     *RTT<=300ms (after version 5.2)

     *BW>=128K

     *MTU>=500Bytes

2. Between Local mode LAP and WLC:

     *RTT<=?

     *BW>=?

     *MTU?

     *anything else?

3. Between Anchor WLC and Foreign WLC:

     *RTT<=?

     *BW>=?

     *MTU?

     *anything else?

4. Between WLC and WLC(when they belong to the same mobility group):

     *RTT<=?

     *BW>=?

     *MTU?

     *anything else?

5. Between WLC and WCS:

     *RTT<=?

     *BW>=?

     *MTU?

     *anything else?

6. Between WLC and MSE:

     *RTT<=?

     *BW>=?

     *MTU?

     *anything else?

7. Between WCS and MSE:

     *RTT<=?

     *BW>=?

     *MTU?

     *anything else?

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