LAP/CAPWAP latency limitations

clarkmat · ‎03-18-2009

I have a general question regarding upgrading older access points, specifically 1231G to LAP or CAPWAP. I know that H-REAP is not supported on this model but wonder what the limitations are for normal Local mode operation is. For example if the LAP is 50msec away from the controller will the LAP work?

Is it dependant on the bandwidth and wether the LWAPP control messages are prioritized?

Around a campus LAN there would be no difficulty using these models with LAP or CAPWAP but what about remote sites where deploying lots of controllers are not an option.

i would be interested in hearing from people who has had experience in deploying 1st generation access points such as 1231G and migrating them to LAP.

Thanks in advance

Scott Fella · ‎03-18-2009

Those ap's will not use CAPWAP, but will use LWAPP. I have clients that we have converted these ap's to LAP with no issues. One thing you can do is convert one of these and test it out.... you can always convert it back to IOS. If the LAP is 50msec away will it work, well like you said, it depends if the control messages reaches the wlc and gets back to the ap. QoS might be your answer if the ap isn't able to join the wlc or when there is heavy traffic and control messages never makes it accross. Like you mentioned, these ap's do not support h-reap, so your remote sites will either need to be upgraded to an ap that supports h-reap or just leave them in autonomous until you can swap them out.

-Scott
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clarkmat · ‎03-18-2009

what kind of latency have you managed to obtain between LAP and WLC? same as h-reap limitation of 100ms? is that the supported limit or is it possible to extend it, to say 150ms?

Scott Fella · ‎03-18-2009

Most of my install with ap's in local mode, is below 20msec... but that doesn't mean it will not work. In h-reap, you can go about 150msec. Here is a good link to look at unless you have already seen it. It shows you what Cisco recommends:)

http://www.cisco.com/application/pdf/paws/99947/lwapp-traffic-study.pdf

-Scott
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clarkmat · ‎03-18-2009

i have seen that doc already, thanks anway and thanks for your comments

Scott Fella · ‎03-18-2009

I don have clients though that have h-reap ap's overseas with no issues... but it is still under 150msec.

-Scott
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