WLC 5520 download speed

[l.buschi]

My WIFI network is made of 5520 WLC and 1832 APS. WLC ver Rel 8.5.

If my clients try to download a big file tha download speed decrease till stop and some applications can't work.

Apparently it happens with all nic model and also if the wireless clients is not moving.

I checked all roaming feature with tac and no errors were detected with roaming.

(Now i Know it happens also with a laptop which is stable over a table).

What may I check?

Tks Johnny

[cmarva]

not sure if this would be the case here, I've never worked with 1800s. But it does sound strangely similar to a problem I've seen in the past with 3802s, and it goes to needing to set the TCP MSS. I believe this is covered now in the WLC best practices doc.

you can try this on a couple and see if it helps at all.

[Leo Laohoo]

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@l.buschi wrote:

If my clients try to download a big file tha download speed decrease till stop and some applications can't work.

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Have you tried looking at the CPU of the the server where this application is being hosted when this downloading is in progress?

What is the exact version the WLC running on?

[l.buschi]

HW Version: 

AIR-CT5520-K9 

connected to the network with two 10G link in LAG.

FW Version:

8.5.135.0

AP models:

all my APs are AIR-AP1832I-E-K9

My WIFI Network is composed by 72 APs and normally has very few clients associated: about 50 clients in total network. No more than 2 -3 clients per APs. some AP have no client associated at all. (it's an hospital network).

In a few hours I'll let my costumer check server CPU, by the way the same operations are working perfectly if done with a wired connection.

It seems that download stops or severely degrades even with a laptop not moving, lying over a table.

I need to have more information about operative systems: I suspect but not sure it could be W8.1.

tried with different model/vendor laptop with the same result.