Packet Loss on 2800 AP

[Ben Duff]

Hi,

We've recently installed some 2800 series APs, we're seeing significant packet loss on two identical Windows 10 Intel 8260 clients. Only appears to be when connected to a 2800 AP. We're running 8.3.102.0 on our 5500 controllers. Downgrading to 8.2.121.0 currently to troubleshoot. Any bugs?

Thanks
Ben

[Ben Duff]

Hi,

This post https://blog.michaelfmcnamara.com/2016/08/lenovo-thinkpad-t460-yoga-with-intel-ac-8260-wireless-issues/ may have been mentioned here. What we find it if we change the mode it stops connecting at AC speeds. If we select VHT/866Mbps, HT/300Mbps and Disable/54Mbps.

Are Cisco or Intel going to come up with a solution for these problems?

Ben

[Males]

FYI: according to my sources this happens if the 8260 is connected to APs controlled by a WLC that uses A-MSDU aggregation. If you are using A-MPDU (it's std for the 8260 because it's an AC card) you won't run into the issue.

So 3 solutions:

1-Deactivate the VHT/HT mode on the card (to avoid using aggregation)

2-Use driver 18.30 on the nic and turn off auto updates

3-Change your packet aggregation config...

It's an issue that has been seen on laptops at Cisco and so far it's linked to the fact 8260 can't digest some large a-msdu's with certain driver versions (though why this size a-msdu is seen from APs isn't known)

Cheers!

[Males]

Great news!

It is an Intel bug but Cisco refences it here: CSCvb26086

Intel drivers v19.2 is supposed to solve the issue, or the workarounds I've previously mentioned....

:)

[quintin.hassell]

Just tried version 19.20 with the same issues. Looks like it won't be corrected until 19.20.1 after looking at the bug you mentioned. We installed driver version 18.30 like you suggested above and that seems to be the best fix for us right now until the new version comes out. Thanks for all of the info you posted!

[Ben Duff]

Hi,

What builds of Windows 10 are you running? Also are you able to share the bug comments as we don't seem to have permission?

Thanks
Ben

[alexandre.rogoski]

That didn't fix to me. (Neither MSS, neither Disable-NetAdapterRsc.)

Running Chipset 8260 + Driver 19.60.0.7 + WLC 8.4.100.0 (AP 3802i).

Stuck at 173,3 Mbps

[patoberli]

Are you running 20 MHz channels? 173 is the maximum on a 20 MHz channel. For more you need 40, 80 or 160 MHz channels.

[alexandre.rogoski]

I guess not... Here it is:

[alexandre.rogoski]

Found my problem...

What was limiting connection to 173 Mbps is that RF Profile was set in WLANs -> AP Groups. All RF Profiles was setting Channel Width to 20 MHz.

Just set RF Profile to None in AP Group for now.

[denysmonteiro]

Hi.

I Have a problem with 2800/3800 APs. I'm using VDI application and users report low performance.

In all 2800/3800 APs I can see very counters in "RxIncompleteFragment" and the counters is the same in "RxDataPacketCount". Anyone know what that means? 

In another APs (3502 and 3602), the counter is 0 for "RxIncompleteFragment".

WLC 5520 with 8.3.121 version.

APs 2802e + Antena 2566D4M

APs 3802i

=========================================================

(Cisco Controller) >show ap stats 802.11a SCBRJK-P6-AP-09

Number Of Slots.................................. 2
AP Name.......................................... SCBRJK-P6-AP-09
Radio Type....................................... RADIO_TYPE_80211a
Stats Information
Number of Users................................ 29
TxFragmentCount................................ 206869058
MulticastTxFrameCnt............................ 4736145
FailedCount.................................... 79222983
RetryCount..................................... 79222983
MultipleRetryCount............................. 13582553
FrameDuplicateCount............................ 0
RtsSuccessCount................................ 27820133
RtsFailureCount................................ 4467086
AckFailureCount................................ 0
RxIncompleteFragment........................... 458925780
MulticastRxFrameCnt............................ 5990265
FcsErrorCount.................................. 0
TxFrameCount................................... 206869058
WepUndecryptableCount.......................... 0
TxFramesDropped................................ 43611
RxErrorFrameCount.............................. 0
MacMicErrorFrameCount.......................... 0
MacDecryptErrorFrameCount...................... 0
ReplayErrorFrameCount.......................... 0
RxMgmtFrameCount............................... 9509527
RxCtrlFrameCount............................... 27820133
RxDataFrameCount............................... 458925780
TxMgmtFrameCount............................... 1098010
TxCtrlFrameCount............................... 32287219
TxDataFrameCount............................... 206869058
RxDataPacketCount.............................. 458925780
TxDataPacketCount.............................. 206869058
Rate Limiting Stats:
Wlan 1:
Number of Data Packets Recieved.............. 0
Number of Data Rx Packets Dropped............ 0
Number of Data Bytes Recieved................ 0

[patoberli]

Not sure about the packet counters, but if you run VMware VDI based on PCoIP (not the brand new Blast protocol), make sure to have the feature Application Visibility and Control enabled, configured (give PCoIP Gold priority) and assigned to the BSSID.

See my screenshots for the required configuration.

This way, I have great results on my mixed WiFi.

Please note, this requires you to use PCoIP, make sure with your VDI people you're actually using that.

Also, my BSSID is configured for normal Bronze QoS and it's shared by many users.

Oh and please, next time open a new thread for a new question :)

[nguyenducviet1983]

Hi Ben, Can you share how to solve this issue?

Thank you.