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Wireless association performance

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  • 1.  Wireless association performance

    Posted Dec 04, 2020 01:30 PM
    I was wondering if someone would be willing to compare performance stats with me.  This is typical of what I see if I look at Clarity in Airwave at connections that a student's computer is making to our wireless network.  They're connecting to our WPA2 Enterprise Secure SSID in this case:


    If I switch over to list view, it further breaks it down, and shows that the majority of that authentication time is Dot1x and only a small part is the WPA 4way hand shake.

    I'm wondering what speed is a good amount of speed for this to happen in.  At some threshold, it would seem like this would get to be a problem as clients connect and roam and disconnect and reconnect.  We're measuring in milliseconds here, but sometimes it's fully twice as long to authenticate as other times.

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    Adam Forsyth
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  • 2.  RE: Wireless association performance

    EMPLOYEE
    Posted Dec 07, 2020 05:33 AM
    Adam,

    I think the authentication times are on the high side. If you have ClearPass, you can check in the detailed logs where most time is spent and backend (like Active Directory) lookups are common reasons for slow responses. Could it be that your authentication servers or their backends are busy/overloaded/under-resourced? Or that some servers are not (always) responding? Mentioning this as most values are around 0, 500, 1000 ms, which could be a timeout with failover to a next server. Also, check if DNS is working properly and performant.

    The differences typically have to do with cached information in some part of the chain, or in not-so-busy environments that processes involved in the authentication are swapped out to disk, after which the first authentication will take more time to get the process back in memory.

    With these values, even 500ms is quite high, I would further dig down where exactly is the delay in the authentication process and address that. Depending on the complexity of your authentication workflow, on a low-latency network (LAN/Campus, no WAN connections involved), you should be able to achieve below 100ms.

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    Herman Robers
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    If you have urgent issues, always contact your Aruba partner, distributor or Aruba TAC Support. Check https://www.arubanetworks.com/support-services/contact-support/ for how to contact Aruba TAC.
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