Re: Multiple clients on same AP, noise on the channel

Clem58 · ‎10-02-2019

Hello,

We have implemented a WH Wireless, with 3802E APs in flexconnect (local switching) and WLC 5520, as per Best Practices, we have set static Channels and Power.

We have conducted a Wireless survey in both 2.4Ghz and 5Ghz, the coverage is really good, and SNR values are not higher than 20 dB.

Today, we have detected a zone had issues, some scanners are disconnected while the signal should be really good in this zone. What I have noticed is, in this zone today they have installed the scanners dock stations to charge them. In fact there around 15 scanners connected here on wireless while they are charging.

I've asked to power off all the charging scanners, and the Wireless connection is now good in this zone.

What does that mean ? I though an AP could cover easily more than 20 clients connections ? Could it be an issue with the current channel here ? We have set 1, 6, 11 but we have a little channel overlapping in this zone on channel 6. However the nearest AP is on channel 11. I did not verify but I assume the scanners were connected on this AP.

Currently the client balancing is off on the WH scanners dedicated SSID, do you thing enabling it could help ? Or do you see any other setting that could improve this issue ?

patoberli · ‎10-02-2019

The amount of clients shouldn't be an issue at all. Even less so while they are charging.
Do they maybe use wireless charging? That could cause issues.
Can you output a 'show client detail macaddressofaffectedclient' from the WLC while the client is in that area?
Can you output a 'show ap stats 802.11-abgn apname'? If that command doesn't output anything, use 802.11b instead of 802.11-abgn.

Clem58 · ‎10-02-2019

Nope no wireless charging, they are plug in a dock station connected on normal power.

Here is the client details:

Client MAC Address............................... xx:xx:xx:xx:xx:xx
Client Username ................................. N/A
AP MAC Address................................... xx:xx:xx:xx:xx:xx
AP Name.......................................... AP123
AP radio slot Id................................. 0
Client State..................................... Associated
Client User Group................................
Client NAC OOB State............................. Access
Wireless LAN Id.................................. 2
Wireless LAN Network Name (SSID)................. SSID2
Wireless LAN Profile Name........................ SSID2
Hotspot (802.11u)................................ Not Supported
BSSID............................................ xx:xx:xx:xx:xx:xx
Connected For ................................... 2 secs
Channel.......................................... 1
IP Address....................................... 10.xxx.xxx.x
Gateway Address.................................. 10.xxx.xxx.x
Netmask.......................................... 255.255.255.0
Association Id................................... 137
Authentication Algorithm......................... Open System
Reason Code...................................... 1
Status Code...................................... 0

--More-- or (q)uit
Session Timeout.................................. 1800
Client CCX version............................... No CCX support
QoS Level........................................ Silver
Avg data Rate.................................... 0
Burst data Rate.................................. 0
Avg Real time data Rate.......................... 0
Burst Real Time data Rate........................ 0
802.1P Priority Tag.............................. disabled
CTS Security Group Tag........................... Not Applicable
KTS CAC Capability............................... No
Qos Map Capability............................... No
WMM Support...................................... Enabled
APSD ACs....................................... BK BE VI VO
Supported Rates.................................. 11.0,12.0,18.0,24.0,36.0,
............................................. 48.0,54.0
Mobility State................................... Local
Mobility Move Count.............................. 0
Security Policy Completed........................ Yes
Policy Manager State............................. RUN
Audit Session ID................................. f004710a0013c7e38ba8945d
AAA Role Type.................................... none
Local Policy Applied............................. none
IPv4 ACL Name.................................... none

--More-- or (q)uit
FlexConnect ACL Applied Status................... Unavailable
IPv4 ACL Applied Status.......................... Unavailable
IPv6 ACL Name.................................... none
IPv6 ACL Applied Status.......................... Unavailable
Layer2 ACL Name.................................. none
Layer2 ACL Applied Status........................ Unavailable
Client Type...................................... SimpleIP
mDNS Status...................................... Disabled
mDNS Profile Name................................ none
No. of mDNS Services Advertised.................. 0
Policy Type...................................... WPA2
Authentication Key Management.................... PSK
Encryption Cipher................................ CCMP (AES)
Protected Management Frame ...................... No
Management Frame Protection...................... No
EAP Type......................................... Unknown
FlexConnect Data Switching....................... Local
FlexConnect Dhcp Status.......................... Local
FlexConnect Vlan Based Central Switching......... No
FlexConnect Authentication....................... Central
FlexConnect Central Association.................. No
FlexConnect VLAN NAME............................ management
Quarantine VLAN.................................. 0

--More-- or (q)uit
Access VLAN...................................... 32
Local Bridging VLAN.............................. 4
Client Capabilities:
CF Pollable................................ Not implemented
CF Poll Request............................ Not implemented
Short Preamble............................. Implemented
PBCC....................................... Not implemented
Channel Agility............................ Not implemented
Listen Interval............................ 3
Fast BSS Transition........................ Not implemented
11v BSS Transition......................... Not implemented
Client Wifi Direct Capabilities:
WFD capable................................ No
Manged WFD capable......................... No
Cross Connection Capable................... No
Support Concurrent Operation............... No
Fast BSS Transition Details:
Client Statistics:
Number of Bytes Received................... 0
Number of Bytes Sent....................... 0
Total Number of Bytes Sent................. 0
Total Number of Bytes Recv................. 0
Number of Bytes Sent (last 90s)............ 2706

--More-- or (q)uit
Number of Bytes Recv (last 90s)............ 917
Number of Packets Received................. 0
Number of Packets Sent..................... 0
Number of Interim-Update Sent.............. 0
Number of EAP Id Request Msg Timeouts...... 0
Number of EAP Id Request Msg Failures...... 0
Number of EAP Request Msg Timeouts......... 0
Number of EAP Request Msg Failures......... 0
Number of EAP Key Msg Timeouts............. 0
Number of EAP Key Msg Failures............. 0
Number of Data Retries..................... 0
Number of RTS Retries...................... 0
Number of Duplicate Received Packets....... 0
Number of Decrypt Failed Packets........... 0
Number of Mic Failured Packets............. 0
Number of Mic Missing Packets.............. 0
Number of RA Packets Dropped............... 0
Number of Policy Errors.................... 0
Radio Signal Strength Indicator............ Unavailable
Signal to Noise Ratio...................... Unavailable
Client Rate Limiting Statistics:
Number of Data Packets Received............ 0
Number of Data Rx Packets Dropped.......... 0

--More-- or (q)uit
Number of Data Bytes Received.............. 0
Number of Data Rx Bytes Dropped............ 0
Number of Realtime Packets Received........ 0
Number of Realtime Rx Packets Dropped...... 0
Number of Realtime Bytes Received.......... 0
Number of Realtime Rx Bytes Dropped........ 0
Number of Data Packets Sent................ 0
Number of Data Tx Packets Dropped.......... 0
Number of Data Bytes Sent.................. 0
Number of Data Tx Bytes Dropped............ 0
Number of Realtime Packets Sent............ 0
Number of Realtime Tx Packets Dropped...... 0
Number of Realtime Bytes Sent.............. 0
Number of Realtime Tx Bytes Dropped........ 0
Nearby AP Statistics:
AP125(slot 0)
antenna0: 92 secs ago.................... -83 dBm
antenna1: 92 secs ago.................... -83 dBm
AP108(slot 0)
antenna0: 2 secs ago..................... -78 dBm
antenna1: 2 secs ago..................... -78 dBm
AP129(slot 0)
antenna0: 2 secs ago..................... -59 dBm

--More-- or (q)uit
antenna1: 2 secs ago..................... -59 dBm

AP111(slot 0)
antenna0: 2 secs ago..................... -61 dBm
antenna1: 2 secs ago..................... -61 dBm
AP113(slot 0)
antenna0: 2 secs ago..................... -51 dBm
antenna1: 2 secs ago..................... -51 dBm
AP118(slot 0)
antenna0: 2 secs ago..................... -66 dBm
antenna1: 2 secs ago..................... -66 dBm
AP115(slot 0)
antenna0: 2 secs ago..................... -70 dBm
antenna1: 2 secs ago..................... -70 dBm
AP107(slot 0)
antenna0: 2 secs ago..................... -65 dBm
antenna1: 2 secs ago..................... -65 dBm
AP117(slot 0)
antenna0: 2 secs ago..................... -83 dBm
antenna1: 2 secs ago..................... -83 dBm
AP103(slot 0)
antenna0: 2 secs ago..................... -75 dBm
antenna1: 2 secs ago..................... -75 dBm
AP122(slot 0)

--More-- or (q)uit
antenna0: 2 secs ago..................... -72 dBm
antenna1: 2 secs ago..................... -72 dBm
AP123(slot 0)
antenna0: 2 secs ago..................... -53 dBm
antenna1: 2 secs ago..................... -53 dBm
AP120(slot 0)
antenna0: 2 secs ago..................... -67 dBm
antenna1: 2 secs ago..................... -67 dBm
AP104(slot 0)
antenna0: 2 secs ago..................... -85 dBm
antenna1: 2 secs ago..................... -85 dBm
AP105(slot 0)
antenna0: 2 secs ago..................... -80 dBm
antenna1: 2 secs ago..................... -80 dBm
AP126(slot 0)
antenna0: 2 secs ago..................... -87 dBm
antenna1: 2 secs ago..................... -87 dBm
AP127(slot 0)
antenna0: 25 secs ago.................... -88 dBm
antenna1: 25 secs ago.................... -88 dBm
DNS Server details:
DNS server IP ............................. 10.xxx.x.x
DNS server IP ............................. 10.xxx.x.xxx

Assisted Roaming Prediction List details:

Client Dhcp Required: False
Allowed (URL)IP Addresses
-------------------------

AVC Profile Name: ............................... none

And AP details:

Number Of Slots.................................. 2
AP Name.......................................... AP123
MAC Address...................................... xx:xx:xx:xx:xx:xx
Radio Type....................................... RADIO_TYPE_80211abgn
Stats Information
Number of Users................................ 0
TxFragmentCount................................ 23384954
MulticastTxFrameCnt............................ 37267144
FailedCount.................................... 40804939
RetryCount..................................... 0
MultipleRetryCount............................. 0
FrameDuplicateCount............................ 0
RtsSuccessCount................................ 0
RtsFailureCount................................ 0
AckFailureCount................................ 0
RxIncompleteFragment........................... 172387441
MulticastRxFrameCnt............................ 129617798
FcsErrorCount.................................. 0
TxFrameCount................................... 23384954
WepUndecryptableCount.......................... 0
TxFramesDropped................................ 1031

--More-- or (q)uit
RxErrorFrameCount.............................. 0
MacMicErrorFrameCount.......................... 0
MacDecryptErrorFrameCount...................... 0
ReplayErrorFrameCount.......................... 0
RxMgmtFrameCount............................... 0
RxCtrlFrameCount............................... 0
RxDataFrameCount............................... 172387441
TxMgmtFrameCount............................... 0
TxCtrlFrameCount............................... 0
TxDataFrameCount............................... 23384954
RxDataPacketCount.............................. 172387441
TxDataPacketCount.............................. 23384954
Rate Limiting Stats:
Wlan 7:
Number of Data Packets Recieved.............. 0
Number of Data Rx Packets Dropped............ 0
Number of Data Bytes Recieved................ 0
Number of Data Rx Bytes Dropped.............. 0
Number of Realtime Packets Recieved.......... 0
Number of Realtime Rx Packets Dropped........ 0
Number of Realtime Bytes Recieved............ 0
Number of Realtime Rx Bytes Dropped.......... 0
Number of Data Packets Sent.................. 0

--More-- or (q)uit
Number of Data Tx Packets Dropped............ 0
Number of Data Bytes Sent.................... 0
Number of Data Tx Bytes Dropped.............. 0
Number of Realtime Packets Sent.............. 0
Number of Realtime Tx Packets Dropped........ 0
Number of Realtime Bytes Sent................ 0
Number of Realtime Tx Bytes Dropped.......... 0
Wlan 2:
Number of Data Packets Recieved.............. 0
Number of Data Rx Packets Dropped............ 0
Number of Data Bytes Recieved................ 0
Number of Data Rx Bytes Dropped.............. 0
Number of Realtime Packets Recieved.......... 0
Number of Realtime Rx Packets Dropped........ 0
Number of Realtime Bytes Recieved............ 0
Number of Realtime Rx Bytes Dropped.......... 0
Number of Data Packets Sent.................. 0
Number of Data Tx Packets Dropped............ 0
Number of Data Bytes Sent.................... 0
Number of Data Tx Bytes Dropped.............. 0
Number of Realtime Packets Sent.............. 0
Number of Realtime Tx Packets Dropped........ 0
Number of Realtime Bytes Sent................ 0

--More-- or (q)uit
Number of Realtime Tx Bytes Dropped.......... 0
Wlan 4:
Number of Data Packets Recieved.............. 0
Number of Data Rx Packets Dropped............ 0
Number of Data Bytes Recieved................ 0
Number of Data Rx Bytes Dropped.............. 0
Number of Realtime Packets Recieved.......... 0
Number of Realtime Rx Packets Dropped........ 0
Number of Realtime Bytes Recieved............ 0
Number of Realtime Rx Bytes Dropped.......... 0
Number of Data Packets Sent.................. 0
Number of Data Tx Packets Dropped............ 0
Number of Data Bytes Sent.................... 0
Number of Data Tx Bytes Dropped.............. 0
Number of Realtime Packets Sent.............. 0
Number of Realtime Tx Packets Dropped........ 0
Number of Realtime Bytes Sent................ 0
Number of Realtime Tx Bytes Dropped.......... 0
Call Admission Control (CAC) Stats
Voice Bandwidth in use(% of config bw)......... 0
Voice Roam Bandwidth in use(% of config bw).... 0
Total channel MT free........................ 24500
Total voice MT free.......................... 23437

--More-- or (q)uit
Na Direct.................................... 0
Na Roam...................................... 0
Video Bandwidth in use(% of config bw)......... 0
Video Roam Bandwidth in use(% of config bw).... 0
Total BW in use for Voice(%)................... 0
Total BW in use for SIP Preferred call(%)...... 0
WMM TSPEC CAC Call Stats
Total num of voice calls in progress........... 0
Num of roaming voice calls in progress......... 0
Total Num of voice calls since AP joined....... 0
Total Num of roaming calls since AP joined..... 0
Total Num of exp bw requests received.......... 0
Total Num of exp bw requests admitted.......... 0
Num of voice calls rejected since AP joined.... 0
Num of roam calls rejected since AP joined..... 0
Num of calls rejected due to insufficent bw.... 0
Num of calls rejected due to invalid params.... 0
Num of calls rejected due to PHY rate.......... 0
Num of calls rejected due to QoS policy........ 0
SIP CAC Call Stats
Total Num of calls in progress................. 0
Num of roaming calls in progress............... 0
Total Num of calls since AP joined............. 0

--More-- or (q)uit
Total Num of roaming calls since AP joined..... 0
Total Num of Preferred calls received.......... 0
Total Num of Preferred calls accepted.......... 0
Total Num of ongoing Preferred calls........... 0
Total Num of calls rejected(Insuff BW)......... 0
Total Num of roam calls rejected(Insuff BW).... 0
WMM Video TSPEC CAC Call Stats
Total num of video calls in progress........... 0
Num of roaming video calls in progress......... 0
Total Num of video calls since AP joined....... 0
Total Num of video roaming calls since AP j.... 0
Num of video calls rejected since AP joined.... 0
Num of video roam calls rejected since AP j.... 0
Num of video calls rejected due to insuffic.... 0
Num of video calls rejected due to invalid .... 0
Num of video calls rejected due to PHY rate.... 0
Num of video calls rejected due to QoS poli.... 0
SIP Video CAC Call Stats
Total Num of video calls in progress........... 0
Num of video roaming calls in progress......... 0
Total Num of video calls since AP joined....... 0
Total Num of video roaming calls since AP j.... 0
Total Num of video calls rejected(Insuff BW.... 0

--More-- or (q)uit
Total Num of video roam calls rejected(Insu.... 0
Band Select Stats
Num of dual band client ....................... 0
Num of dual band client added.................. 0
Num of dual band client expired ............... 0
Num of dual band client replaced............... 0
Num of dual band client detected .............. 0
Num of suppressed client ...................... 0
Num of suppressed client expired............... 0
Num of suppressed client replaced.............. 0

patoberli · ‎10-02-2019

This output here is weird:
Radio Signal Strength Indicator............ Unavailable
Signal to Noise Ratio...................... Unavailable

Not sure why it is. Can you check with one or two other clients?
Normal output should look like this (on a 5520 WLC, which uses completely different software):
Radio Signal Strength Indicator............ -52 dBm
Signal to Noise Ratio...................... 42 dB

Clem58 · ‎10-02-2019

Ha yes you are right, I think the client was just disconnected when I typed the command, with another client we have the right information appearing:

      Number of Policy Errors.................... 0
      Radio Signal Strength Indicator............ -56 dBm
      Signal to Noise Ratio...................... 34 dB

In fact, all the handheld scanners have been put in their docking stations for charging at the same time, maybe it's a client related issue and not Wireless related. I need to do some tests with SkorpioX4 from Datalogic, I Wonder if the Wireless is disconnecting when we plug it on the dock station.

patoberli · ‎10-03-2019

It's well possible, because "you don't need the scanners while they are charging" could be a common thinking of the manufacturer.

Clem58 · ‎10-04-2019

Thanks for your answer, I've confirmed that the scanners are not disconnecting while we plug them or unplug them from the dock stations.

However I can see in the logs of multiple APs this kind of alerts:

invalid staid xxx received

We don't see these alerts on the other APs, only on 5 APs, including the one covering the zone where we have issue.

I know our WLC code has a lot of bugs with 3802 APs (8.2.130.0), maybe we need to restart them to fix the issue ?

Last question: what is the best way to restart the AP, from the GUI/CLI and do a "reset", or shut the switch port and unshut .

patoberli · ‎10-04-2019

I suggest you first upgrade the WLC to 8.2.170.0. This will cause all APs to reboot anyway.

I suggest doing the reset in the GUI/CLI, this is a tiny bit safer than killing the power (assuming PoE) every time.

Clem58 · ‎10-04-2019

I knew you will tell me to upgrade, the issue is I cannot take this decision, and the ones who can are scared because we have +300 APs all over Europe on it and they don't want to have any issue as this is really critical.

I'll have to push them for upgrading anyway.

patoberli · ‎10-04-2019

Yes really do. The release is now out for quite a while and deemed stable, besides you already have issues ;)

Make sure to pre-load the image on the APs before reloading the WLC, that should give more security.
You are btw. also affected of a critical flash issue on the APs (not the 3800, previous models) if you have them in use:
https://www.cisco.com/c/en/us/support/docs/wireless-mobility/wireless-lan-wlan/213317-understanding-various-ap-ios-flash-corru.html
This is fixed in the 8.2.170.0 release. The longer you use the old release, the higher the probability of the issue. Please note, 8.2 is end of life and 8.2.170.0 should be the latest release (there is a beta version, in case you have 702w APs in use), more info:
https://www.cisco.com/c/en/us/support/docs/wireless/wireless-lan-controller-software/200046-tac-recommended-aireos.html

Clem58 · ‎10-04-2019

Many thanks for your comprehsensive answer !

Clem58 · ‎10-21-2019

An update to this issue, we have found a lot of "invalid staid" in the logs of our 3802 APs, I think it's corresponding with the fact the clients have been 'rejected'.

Then we have reboot every APs that had these errors in their logs, and we haven't any issue now, but I'm not sure it won't happen again.

I've searched some information about this "bug" and it seems it's again related with our fw version :(