Problems with old WLAN Clients after changing the WLAN infrastructure

[Anonymous]

Hello,

we switched our wlan infrastructure at one of our warehouses from old Motorola Symbol Aps using a WEP SSID to our new wlan infrastructure using the XIQ Cloud, with primarily AP410 and a PPSK SSID, using one PPSK for every forklift in the warehouse. (They use an old Win7 embedded OS).

After the switch we noticed several disconnects within the Logistics Software we are using on the terminals to manage the warehouse. We Software keeps losing the connection to the server for a few seconds (from 2-3 seconds to 15-20) and then reconnects. It seems like it’s happening all over the warehouse, even at locations where i can see with our other devices that the wlan connections seems good and stable. What i’ve noticed is that it looks like some sort of roaming problem to me. It seems to me like it is some sort of roaming problem. Maybe the terminals take too long to roam between the aps or having problems with PPSK authentication?

I checked the client monitor to check the clients and noticed a poor client health. Seeing many issues displayed as “The client is configured with an incorrect static IP address or gateway.” Which in fact, seems not to be correct. The forklifts are configured with a static ip, dns and gateway (we dont use DHCP in this VLAN). So what is the cause of this error? Could the be also a hint to our main wlan problem? 

If you need any more information, dont hesitate to ask. I appreciate every help. 🙂

[dpanev]

You could try to reduce the radio power to 13-15 db and check it again

[Anonymous]

Hello Ovais,

1. we replaced around 67 Motorlas with 50 Extreme APs. I should note that we got a few outdoor APs (460c) and you wont see all APs on the screenshot down below, because the plant split into one Big and one small hall which i did not screenshot.

2. On the whole plant? Around 20-30 (10 forklifts, most of the rest are iphones using 5 Ghz in a sepperate SSID)
3. This is a screenshot of our plan. Sadly we dont have a good layout of the plant, i also haven’t done walls yet, since i dont exactly know where which kind of wall is. In the areas where you can see more APs we have full water / softdrink bottles (we are a Beverage manufacturer) and this results in the water absorbing the wlan signal and creating signal holes. So we needed to place more APs to cover up the holes.
   I have created a schedule for the aps to check their neighbor channels every evening and switch channels, if needed.

4. 

   Here a Screenshot like you requested it. I hope you can see everything you need.
    

   

   I noticed that i dont see any “roaming time” like in your screenshot. So when i click on the “green bar” i only see the Health Score and errors. 

5. 

   This one is from one of our aps in the truck loading street (2,4Ghz):
   
   #show int wifi0
   AC=access category; be=best-effort; bg=background; vi=video; vo=voice;
   AIFS=Arbitration Inter-Frame Space; Txoplimit=transmission opportunity limit;
   IDP=Intrusion detection and prevention; BGSCAN=background scan; PS=Power save;
   HT=High throughput; A-MPDU=Aggregate MAC protocol data unit;
   DFS=Dynamic Frequency Selection; CU=Channel Utilization;
   EIRP=Effective Isotropic Radiated Power (Transmit Power + Max Antenna Gain + Max                                     TX Chains Gain);
   OFDMA=Orthogonal Frequency Division Multiple Access;
   BSS_Color= Basic Service Set Color; TWT=Target Wake Time;

   Summary state=Fair;
   Mode=access; Radio disabled=no;
   Admin state=enabled; Operational state=up;
   MAC addr=bcf3:103f:6690; MTU=1500;
   Freq(Chan)=2462Mhz(11); EIRP power=17.01dBm(10dBm + 4.00dBi + 3.01dBi); Diversit                                    y=disabled;
   Tx range=300m; Noise floor=-96dBm; Tx power control=disabled;
   Radio profile=default_2.4ghz_gn; IDP profile=N/A;
   Application Essentials profile=N/A;
   Presence profile=N/A; Presence state=disabled;
   Beacon interval=100; Max clients number=100;
   Phymode=11ng; Short preamble mode=enabled;
   Tx Chain=static 2; Rx Chain=static 2;
   A-MPDU=enabled; Short guard interval=enabled;
   Channel width=20Mhz; HT-protection=Legacy protect; Deny client=none;
   AC=be; CWmin=4; CWmax=6; AIFS=3; Txoplimit=0; NoACK=disabled;
   AC=bg; CWmin=4; CWmax=10; AIFS=7; Txoplimit=0; NoACK=disabled;
   AC=vi; CWmin=3; CWmax=4; AIFS=1; Txoplimit=3008; NoACK=disabled;
   AC=vo; CWmin=2; CWmax=3; AIFS=1; Txoplimit=1504; NoACK=disabled;
   Rx packets=276887294; errors=  48723; dropped=    1;
   Tx packets= 34298939; errors=4230276; dropped=21125;
   Rx bytes=524686103 (500.380 MB); Tx bytes=2513043275 (2.340 GB);
   ACSP use last selection=disabled;
   BGSCAN allow=enabled; BGSCAN during voice=disabled; BGSCAN interval=20 minutes;
   BGSCAN with client=enabled; BGSCAN with PS client=disabled;
   Number of BGSCAN=29297; Number of BGSCAN requested=34168; Number of BGSCAN missed=4871;
   DFS=disabled; Number of detected radar signals=0; DFS static-channel restore=disabled;
   LLDP state=N/A; CDP state=N/A;
   Rx airtime=3056.24 s; Tx airtime=16748.40 s; CRC error airtime=1268.70 s;
   Rx airtime percent=0.00%; Tx airtime percent=0.00%; CRC error airtime percent=0.16%;
   Tx utilization=1%; Rx utilization=2%; Interference utilization=1%; Total utilization=4%;
   Backhaul failover=disable;
   Radio-share mode=off; channel-change=disable;
   Running average Tx CU=2%; Rx CU=4%; Interference CU=2%; Noise=-95dBm;
   Short term means average Tx CU=2%; Rx CU=4%; Interference CU=2%; Noise=-95dBm;
   Snapshot Tx CU=2%; Rx CU=4%; Interference CU=1%; Noise=-95dBm;
   CRC error rate=19%;
   Benchmark 11a score=222000; 11b score=50500; 11g score=222000; 11n score=501000; 11ac score=889000; 11ax score=889000;
   OFDMA downlink=disabled;
   OFDMA uplink=disabled;
   TWT=disabled;
   BSS Color=0;
   A-MSDU=disabled; A-MPDU limit=1048575;
   VHT support in 2.4G interface=disabled;
   Frameburst=enabled;
   Alternate radio profile=disabled;
   Primary radio profile=default_2.4ghz_gn;
   DSSS 20Mhz power:
   Board limit=20dBm(1) 20dBm(2) -(3) -(4); Regulatory limit=18dBm(1) 19dBm(2) -(3) -(4);
   Spectral scan=off;
   The signal by pass BPF.
   
   This one from one within the halls:

   show int wifi0
   AC=access category; be=best-effort; bg=background; vi=video; vo=voice;
   AIFS=Arbitration Inter-Frame Space; Txoplimit=transmission opportunity limit;
   IDP=Intrusion detection and prevention; BGSCAN=background scan; PS=Power save;
   HT=High throughput; A-MPDU=Aggregate MAC protocol data unit;
   DFS=Dynamic Frequency Selection; CU=Channel Utilization;
   EIRP=Effective Isotropic Radiated Power (Transmit Power + Max Antenna Gain + Max TX Chains Gain);
   OFDMA=Orthogonal Frequency Division Multiple Access;
   BSS_Color= Basic Service Set Color; TWT=Target Wake Time;

   Summary state=Good;
   Mode=access; Radio disabled=no;
   Admin state=enabled; Operational state=up;
   MAC addr=bcf3:103f:2bd0; MTU=1500;
   Freq(Chan)=2462Mhz(11); EIRP power=21.01dBm(14dBm + 4.00dBi + 3.01dBi); Diversity=disabled;
   Tx range=300m; Noise floor=-96dBm; Tx power control=disabled;
   Radio profile=default_2.4ghz_gn; IDP profile=N/A;
   Application Essentials profile=N/A;
   Presence profile=N/A; Presence state=disabled;
   Beacon interval=100; Max clients number=100;
   Phymode=11ng; Short preamble mode=enabled;
   Tx Chain=static 2; Rx Chain=static 2;
   A-MPDU=enabled; Short guard interval=enabled;
   Channel width=20Mhz; HT-protection=Legacy protect; Deny client=none;
   AC=be; CWmin=4; CWmax=6; AIFS=3; Txoplimit=0; NoACK=disabled;
   AC=bg; CWmin=4; CWmax=10; AIFS=7; Txoplimit=0; NoACK=disabled;
   AC=vi; CWmin=3; CWmax=4; AIFS=1; Txoplimit=3008; NoACK=disabled;
   AC=vo; CWmin=2; CWmax=3; AIFS=1; Txoplimit=1504; NoACK=disabled;
   Rx packets=429368695; errors=  28213; dropped=  4;
   Tx packets=  3433937; errors=1159192; dropped=150;
   Rx bytes=2004640921 (1.867 GB); Tx bytes=877481336 (836.831 MB);
   ACSP use last selection=disabled;
   BGSCAN allow=enabled; BGSCAN during voice=disabled; BGSCAN interval=20 minutes;
   BGSCAN with client=enabled; BGSCAN with PS client=disabled;
   Number of BGSCAN=33692; Number of BGSCAN requested=34110; Number of BGSCAN missed=418;
   DFS=disabled; Number of detected radar signals=0; DFS static-channel restore=disabled;
   LLDP state=N/A; CDP state=N/A;
   Rx airtime=524.79 s; Tx airtime=7886.45 s; CRC error airtime=4025.86 s;
   Rx airtime percent=0.00%; Tx airtime percent=0.00%; CRC error airtime percent=0.12%;
   Tx utilization=2%; Rx utilization=7%; Interference utilization=1%; Total utilization=10%;
   Backhaul failover=disable;
   Radio-share mode=off; channel-change=disable;
   Running average Tx CU=2%; Rx CU=8%; Interference CU=1%; Noise=-95dBm;
   Short term means average Tx CU=1%; Rx CU=7%; Interference CU=1%; Noise=-96dBm;
   Snapshot Tx CU=1%; Rx CU=7%; Interference CU=1%; Noise=-96dBm;
   CRC error rate=7%;
   Benchmark 11a score=222000; 11b score=50500; 11g score=222000; 11n score=501000; 11ac score=889000; 11ax score=889000;
   OFDMA downlink=disabled;
   OFDMA uplink=disabled;
   TWT=disabled;
   BSS Color=0;
   A-MSDU=disabled; A-MPDU limit=1048575;
   VHT support in 2.4G interface=disabled;
   Frameburst=enabled;
   Alternate radio profile=disabled;
   Primary radio profile=default_2.4ghz_gn;
   DSSS 20Mhz power:
   Board limit=20dBm(1) 20dBm(2) -(3) -(4); Regulatory limit=18dBm(1) 19dBm(2) -(3) -(4);
   Spectral scan=off;
   The signal by pass BPF.
   
   6. We already tried it with and without the protocols. No effect.

[Ovais_Qayyum]

Hi,

I guess we also need to know the following about your network:

• How many AP410C did you deploy against AP5131? 
• How many clients do you have connected during the peak time?
• How does the channel and Tx power plan look like? is it set to auto channel selection or are you using a static channel plan? In a healthy RF environment, you should not have channel overlap (neighboring APs shouldn't use the same channels), look out for that. If you have floor plan already setup, you can see the current channel plan under “Network 360 Plan”, share it here if you prefer so we can understand your network better:

• 

   

After you make sure that the channel plan looks good and there is no adjacent channel interference going on,  maybe you can start off by checking the following:

• Pick a client that has shown issues while roaming. Check the following client stats in Client 360. Look for roaming time value and check RSSI, SNR, Floor Noise and Usage. You can probably send a screenshot of this screen from your setup.

• Scroll down on the same screen and check following:

  

• On the AP #show int wifi0 or wifi1 counter // to see stats per interface. Great to see retry, CRC, mDNS counters. If you have retries then you are most probably suffering with an RF problem, either bad coverage, too many APs or too less of APs for far more clients. 
• If you have 11r,11k,11v enabled on the WLAN, I would recommend you disable those and test, even though these are supposed to help you with roaming but many old clients do not support these and if you have it enabled, it may have an adverse effect on the roaming.  

Regards,

Ovais

[Anonymous]

Hello,

Ah ok. Yes, this should be the case. 

To your second question. I will try to get this information. Maybe takes some time (the warehouse is at a other location than my office)

Is there something else i can check? Could you give me some informations about the “application health” in the client monitor?

Edit:
 

I’ve checked the average RSSI of other terminals and noticed that some terminals got an average of -60 to -70 dbm. This, of course, seems to be pretty bad. Could this be caused by much roaming? The warehouse is pretty big and the forklifts often travel through the whole halls.

[Ovais_Qayyum]

Hi, 

You are seeing  “The client is configured with an incorrect static IP address or gateway” because we do alert via Client Monitor under Manage>Tools or from Client360 for a specific device if we suspect a client has a static IP and we're doing that based on DHCP traffic patterns. Currently, this check can’t be disabled. Consider it as a false positive for now because this won’t impact anything.

To your question:

1. How can I find this out? You mean if we have APs that could cover the area of other APs if it goes down?

 (Ovais) What I meant is the coverage overlap which is required for seamless roaming when the client moves between two APs.

Can you confirm that the application does not disconnect if the client is not moving/remains connected to the same AP?

Moving from WEP to PPSK can be one of the reasons as well, PPSK is like WPA2 and it should be treated that way. Make sure your client driver supports WPA2-AES, if it does not, you will have issues. 

I would recommend you update the WLAN driver on one of the clients and run the roaming tests on it.

Regards,

Ovais