Aggressive Load Balancing Per SSI

Hey team,
I was looking through some docs but couldn't find out "WHEN" aggressive load balancing would be available per SSID on a WLC. Does anyone have any feedback on this particular topic? We have some legacy clients and we want to segregate them via WLAN and have the feature available when necessary without supplicants etc.
Thanks in advance!
bigjess

Hi bigjess,
Available as of 6.0.188.0 with 6.0.196.0 being the current maintenance release.
See http://www.cisco.com/en/US/docs/wireless/controller/release/notes/crn6_0_188.html#wp598887
-Matt

Similar Messages

WLC - Aggressive Load Balancing?

Hello,
The Wirless LAN Network bulit is as follows -
1. 1 x 4404 WLC
2. 40 x LWAPP 1131AG Access Points
3. Windows Clients used by the Laptop Clients.
4. Only one Wireless VLAN across the Capmus network - hence AP's, WLC & Clients are all in one VLAN / IP Subnet.
5. No Access Point Group is created.
6. Aggressive Load Balancing is enabled allowing 15 Clients as max connection per Access Point.
Problem facing -
1. Tried configuring the Aggressive Loadbalancing allowing only 2 x Clients per AP. But noticed that the 3rd Client connecting to the same AP as of the previous 2 Clients have connected. 3rd client is not associating to a different AP which is nearby.
Please can one help me, if i'm configuring & testing Aggressive Load Balancing in the right way!
Regards,
Keshava Raju

AMR is on target. In fact I just completed 20 hours worth of testing with variuos clients with ALB for a white paper I am doing. Code 17 isnt honored by most clients and is only sent 1 time from the AP. The clients will contiue to attempt to associate to the AP and the AP will allow them on.
Here is a peek of my white paper "still in draft"
WLC - Cisco WLC Aggressive Load Balancing; What is it and where did it go in 6.0!
I've spent the majority of my WLC experience at code level 4.2. Not by choice really, more
based on the fact that 4.2 is pretty darn stable and it is the only safe harbor to date for the Cisco WLC. Healthcare and Enterprise enviroments are typically slow to move on upgrades, especially when things are operating fine.
Since my latest project involves the deployment of hundreds of Cisco 1142s @ location grade, it required that I move to later code to support the 1142 access points. After much research, conversations with our
local Cisco Wireless SE, conversation with peers at other healthcare organizations, and direct contact with the aware team I had decided that 6.0.188.0 was a release that was of great interest.
As I start to get fimilar with the new code I am starting to see that things got moved around a little. One of the items is Aggressive Load Balancing. If you aren't fimilar with Aggressive Load Balancing (ALB) you definitly need to be and let me share why.
First lets look at what ALB is and how it works and then we will dive into the differences between the 4.2 code and the new options 6.0 gives us. ALB when enabled, allows the Cisco WLC to load balance wireless clients on access points that are joined to the same controller. “Key word here – same controller”. You can configure the load balancing window globally in the controller. What is the load balancing window you ask? Well is the maximum number of clients that should be allowed on the access point BEFORE it will start to load balance.
Lets assume for a moment you have an access point with 5 clients already attached. When client #6 sends association request to the access point the access point will kindly respond with an associaton response frame with the reason code of 17. The wireless client will see reason code 17 in the association response and will kindly find other access points to associate with. However, some devices will ignore this frame and yet still continue to try and associate to the access point. Note: The Cisco WLC will ONLY send 1 reassociation frame with a reason code of 17. It doesn’t flood the medium / client with multiple frames.
Its up to the client to honor this information and move on. But I can tell you from my experience and testing this isn’t always the case.
By default, 4.2 and 6.x both have a load balancing window of (5). Lets look at an example.
The window setting controls when aggressive load−balancing starts. With a window setting of five, for
example, all clients after the sixth client are load−balanced.
I know, what is the reason code talk, right. Lets cover this as well. If you dive into the 802.11 frames you will see “Reason Codes”. When a client sees the reason code of “17”, it indicates to the client that the access point is busy and the client should look else where.
yada yada yada
I will post the complete paper on my site: my80211.com in the next week or so ...

Aggressive Load-balancing feasible?

I am experiencing some issues with laptops in a lab not being able to associate properly.
I'm in a university environment with 132 APs at the current time.
The lab in question is in a building with 6 APs total: 4 on the 2nd floor, 2 on the 1st floor. The lab itself is located on the 2nd floor close to the central point of the 4 APs. They plan to use 30 laptops at once via wireless.
There are also many other areas on campus that have a focused load (common student areas for example).
For the lab specifically, would this be a viable condition to enable load-balancing? I'm thinking a client window of 10 or 12 should work.
All 6 APs can see each other, and all the 2nd floor APs can see at least 3 other APs with -70dBm or more (stronger).
My current threshold is set to -65dBm, but I will be changing that to -70 to meet current recommendations.
Also, what is considered 'high density' in terms of LWAPP deployments? Is there a certain number of 'visible' APs to aim fo r(from each AP's point of view)?
Finally, will changing the threshold and enabling load-balancing require controller reboots, or can I just apply them on the fly?
Thanks.
Edit: My WLCs (1x WiSM blade) are on version 4.2.61.0.

You can enable aggressive load balancing and change the thresholds on the fly. These will not require you to reboot the wlc. High density can vary depending on the applications the users are using. Cisco recommends around 15 to 20 per access point, but that is not a hard number. Aggressive load balancing can help or not help, it is something you have to enable and see how the users are affected by the change.

WLC Voice Audit - Aggressive Load Balancing on WLAN not disabled

I am running v6.0.196 on 2 WLCs. Aggressive Load Balancing is disabled globally via WCS. (Configure / Controller / General / Aggressive Load Balancing = Disabled). When running the Voice Audit Tool against the VoWLAN, I receive the following:
"Aggressive Load Balancing on WLAN not Disabled"
I am unable locate the command or the screen to actually disable this on an individual WLAN. Is this perhaps a code glitch?
-Robert

This is not available on the WCS. I was able to locate this on the individual WLCs.
But thanks for pointing me where to look nonetheless!
-Robert

Load Balancing per packet not working properly

Hi,
I am attaching you the configs of issue. There are two links E1 links from
Karac-1(Serial0/0/0:0 & 0:1) and Karac-2 with (Tunnel10) which were connected with Khask-1w
Now the issue is that Load balancing per packet were not done sucessfully the NMS snap shot is already attached.
Load balancin g only configured in KarAC-1 & 2
What is the resolution of this problem traffic only use on two links but third links were not utilize.
Kind regards,Salman Ahmed

Hi Paolo!
I have one doubt pertaining to per-packet load-sharing. In order to connect my two data-centres- A & B, Site A is having two WAN links and Site B is having two WAN links - one from ISP1 (30Mbps link) and the other from ISP2 (50Mbps link). I am doing static route load balancing using same AD values for both the ISPs. I have configured "ip load-sharing per-packet" on both the outgoing interfaces.
The load is getting distributed equally across both the links but total bandwidth utilization across both the links is not going beyond 30Mbps. The combined bandwidth of both links is 80Mbps (50+30). However links are not getting fully utilized even though heavy load is there on the links. Can you please tell me how to make full use of both the wan links at both the ends? OR Can you tell me how I can distribute the traffic across both the links with full utilization without using per-packet load sharing. Moreover, my links can be configured statically only at both the ends.

Aggressive Load Balancing = unstable network

Last week we upgraded 26 WLCs 4400 controllers from version 5.2.178 to version 6.0.188.0/6.0.196.0.
Two days after the upgrade, IT-administrators had reported problems with 15 of the WLCs.
The symptoms was:
- Problems conntecting to SSIDs
- Unstable network when connected
- Clients didnt get a IP-adress
- Unstable signal strength
After some troubleshooting, it turned out "Aggressive load-balancing" was enabled on the WLCs having these problems.
Output from one WLC:
(Cisco Controller) >show load-balancing
Aggressive Load Balancing........................ Enabled
Aggressive Load Balancing Window................. 0 clients
Aggressive Load Balancing Denial Count........... 3
Statistics
Total Denied Count............................... 5873 clients
Total Denial Sent................................ 14067 messages
Exceeded Denial Max Limit Count.................. 2924 times
None 5G Candidate Count.......................... 8215 times
None 2.4G Candidate Count........................ 2331 times
Yesterday we ran this command on these WLCs:
config load-balancing aggressive disable
..and the problems now seem to have dissappeared.
Aggressive load-balancing is disabled as default in the newest versions of WLC software, but we have upgraded since version 4.0.155.5 (where I think this was enabled as default), and I guess this setting was enabled because of that.
Some info from cisco.com about aggressive load balancing:
Aggressive load-balancing works at the association phase. If enabled and the conditions to load-balance are met, when a wireless client attempts to associate to a LAP, association response frames are sent to the client with an 802.11 response packet that includes status code 17. This code indicates that the AP is too busy to accept any more associations.
It is the responsibility of the client to honor, process or discard that association response frame with reason code 17. Some clients ignore it, even though it is part of the 802.11 specification. The standard dictates that the client driver must look for another AP to connect to since it receives a "busy" message from the first AP it tries. Many clients do not do this and send the association request again. The client in question is allowed on to the wireless network upon subsequent attempts to associate.
Just wanted to post this in case others are experiencing problems like we did

Tweak your RF. You need to adjust the TX power and the data rates. The reason you have one AP with 9 clients is probably because that AP has the lowest TX power setting like 7-8. Make each AP the same TX power level, depending on how many AP's and how big the room is. You will need to play around with this and the data rates to achieve what you want.
Here is a guide to look at too
http://www.cisco.com/web/strategy/docs/education/cisco_wlan_design_guide.pdf
Sent from Cisco Technical Support iPhone App

Aggressive load balancing

hi there,
i am having problems with implementing load balancing successfully. its really churing my head. Can the genious people out here shed me some light on aggressive load balancing. How successful is load balancing? I have not been able to block clients connecting to a light weight AP when it exceeds the maximum clients allowed. Please help

Hi Solomon,
Have a look at this recent thread. There are some excellent
answers which detail this process
https://supportforums.cisco.com/message/3121939#3121939
Cheers!
Rob
Please support CSC Helps Haiti
https://supportforums.cisco.com/docs/DOC-8895
https://supportforums.cisco.com/docs/DOC-8727

How can I debug Aggressive Load Balancing on the WLC ?

Hello Cisco-Experts,
I'm looking for the command on the Cisco WLC to debug Aggressive Load-Balancing.
There is a nice document, ID 107457 describing this feature, but it lacks the command.
Please investigate and help me and maybe improve YOur documentations.
Thanks in advance
Winfried

Hello NetPros,
I have disabled now "Agressive Load Balancing" now on the WLC. To my surprise, still Load-balancing packets are received from our HREAP-APs via a WAN-Link on the central WLC.
Here is an example:
Tue Jan 13 15:35:59 2009: 00:1c:bf:4a:3f:2e LBS data stored for Mobile 00:1c:bf:4a:3f:2e from AP 00:23:5d:0e:e9:e0(0) new saved RS
SI (A -128, B -53), SNR 41, inUse 1, [rcvd RSSI (A -128, B -54), SNR 40]
Tue Jan 13 15:35:59 2009: 00:1c:bf:4a:3f:2e LBS data rcvd for Mobile 00:1c:bf:4a:3f:2e from AP 00:23:5d:0e:e9:e0(0) with RSSI (A -
128, B -55), SNR 42
Tue Jan 13 15:35:59 2009: 00:1c:bf:4a:3f:2e LBS data stored for Mobile 00:1c:bf:4a:3f:2e from AP 00:23:5d:0e:e9:e0(0) new saved RS
SI (A -128, B -54), SNR 41, inUse 1, [rcvd RSSI (A -128, B -55), SNR 42]
It is remarkable that the MAC-addresses of many of the WLAN-clients do not belong to our company and packets are send via a WAN-link.
Why do I see these packets while load-balancing is disabled ?
How is this working ?
Thank You for any explanation.
Winfried

ASA load balance per destination

Hello,
I have an ASA with version 8.4.4.1 connected via a switch to two routers and I have two default routes on the ASA pointing to the two routers.
The question is : Does the ASA load balance the traffic onto the two routers per-destination or per-packet?
As in routers, CEF load balances the connection per-destination by default. So, what about the ASA regardless of the hardware.
Regards,
George

No. Everything will go to lowest cost route. Matthew

Aggressive load balancing - doco default

The doco. Command Reference for v4.0 says,
config load-balancing
is Enabled by default.
I think this is wrong.
WiSM v4.0.179.8

Tweak your RF. You need to adjust the TX power and the data rates. The reason you have one AP with 9 clients is probably because that AP has the lowest TX power setting like 7-8. Make each AP the same TX power level, depending on how many AP's and how big the room is. You will need to play around with this and the data rates to achieve what you want.
Here is a guide to look at too
http://www.cisco.com/web/strategy/docs/education/cisco_wlan_design_guide.pdf
Sent from Cisco Technical Support iPhone App

What does per Wlan Band select and load balancing do ?

Good morning.....We recently upgraded our controllers from 4.2.185 to 6.0.188 and have noticed many clients having connectivity issues. We have Aggressive load balancing turned off globally but have noticed that band select and load balancing are enabled on the
Wlan. Are these settings mutually exclusive or do they do the same thing ? Does the Wlan setting override the default ? We have noticed that there is
output doing "debug dot11 load-balancing"
Thanx.....Dave

I believe we never had load balancing turned on when running 5.2 code. We jumped from 5.2 to 6.x temporarily and then to 7.0 within a 30 day time frame this summer. We're a large university and we had very few users on WiFi during that time.
The Macintosh laptops are having nothing but trouble since school began, and I have gone over everything and found that band select is turned on as well as load balancing. Since band select didn't exist in 5.2 (I believe) I know it wasn't on. As for load balancing, I don't believe it was on, and I discovered it was turned on when recently reviewing our configs.
The Macintosh laptops have been debugged and our Mac gurus tell us they're getting a message that equates to "the AP is busy, or the AP is full". This leads me to believe that load balancing got turned on during the upgrade and we didn't notice, which caused the Macintoshes to have issues.
We don't have any VoWiFi clients so we don't have to support them, and we don't officially support smartphones, either.
I turned off load balancing and will see how it goes....
Thanks!

LWAPP-3-REPLAY_ERR and load balancing issue

Guys, I was trying to troubleshoot this error in my WLC
Nov 24 00:30:01 wlc1: *spamApTask5: Nov 24 00:30:01.883: #LWAPP-3-REPLAY_ERR: spam_lrad.c:35169 The system has received replay error on slot 0, WLAN ID 1, count 1 from AP 08:d0:9f:23:4f:e0
I did some search and I was trying to check if there was any replay attack in the network but I don't know where to start and kept searching for other reasons, and got an anwser in other blog. And this issue could be related to a Load-balancing config.
Eventhough,I've got Load-Balancing disable in all my WLAN's but still got these counters. How can I check if those are false positives?
(wlc-1) >show load-balancing
Aggressive Load Balancing........................ per WLAN enabling
Aggressive Load Balancing Window................. 10 clients
Aggressive Load Balancing Denial Count........... 3
Statistics
Total Denied Count............................... 17682 clients
Total Denial Sent................................ 30891 messages
Exceeded Denial Max Limit Count.................. 5032 times
None 5G Candidate Count.......................... 206270 times
None 2.4G Candidate Count........................ 5040 times
In the GUI the Load-Balancing is DISABLED per WLAN.

yes, even I've upgraded my entire campus to 1702i and 2702i lightweight AP's with 8.0.115.0 code in my WLC I still got huge amount of LWAPP Replay Erros, please check the summuary of erros during yesterday..
     14 APF-1-CONFLICT_IN_ASS_REQ: apf_80211.c
     14 APF-3-CHECK_EXT_SUPP_RATES_FAILED: apf_utils.c
     14 APF-3-CHECK_SUPP_RATES_FAILED: apf_utils.c
     15 APF-3-NO_FRAMED_IP_ADDRESS: apf_radius.c
    638 APF-3-VALIDATE_DOT11i_CIPHERS_FAILED: apf_rsn_utils.c
    103 DOT1X-3-AAA_AUTH_SEND_FAIL: 1x_aaa.c
   2427 DOT1X-3-ABORT_AUTH: 1x_bauth_sm.c
     55 DOT1X-3-AUTHKEY_TX_TRANS_ERR: 1x_kxsm.c
     20 DOT1X-3-CLIENT_NOT_FOUND: dot1x_msg_task.c
   1365 DOT1X-3-INVALID_REPLAY_CTR: 1x_eapkey.c
     69 DOT1X-3-INVALID_WPA_KEY_MSG: 1x_eapkey.c
    296 DOT1X-3-INVALID_WPA_KEY_MSG_STATE: 1x_eapkey.c
      2 DOT1X-3-INVALID_WPA_KEY_STATE: 1x_eapkey.c
    923 DOT1X-3-WPA_SEND_STATE_ERR: 1x_kxsm.c
      7 DTL-3-ARP_CLIENT_IP_DUPLICATED: dtl_arp.c
      2 IPV6-3-CREATE_BINDING_FAILED: ipv6_net.c
      2 IPV6-3-ORPHAN_ADDR_LEARNING_FAILED: ipv6_net.c
      2 LOG-3-Q_IND: 1x_eapkey.c
      3 LOG-3-Q_IND: rrmChanUtils.c
     22 LOG-3-Q_IND: spam_lrad.c
   5120 LWAPP-3-REPLAY_ERR: spam_lrad.c
      2 LWAPP-3-VENDOR_PLD_VALIDATE_ERR: spam_lrad.c
      3 RRM-3-RRM_LOGMSG: rrmChanUtils.c
    615 RRM-3-RRM_LOGMSG: rrmLrad.c
      2 SISF-3-INTERNAL: sisf_shim_utils.c

Email notifications and load balancing

We are load balancing 2 OMS's. The problem is email notifications have embedded links that have the OMS that sent the notification instead of the virtual hostname set-up for the load balancer. The OMS's have been set-up to use the load balancer per the OEM Advanced Configuration and from an agent/Web console perspective, everything is working fine and using the load balanced hostname. Does anyone know where to modify the email notifications so the links point to the load balanced URL rather then the individual OMS host that sent the notification?

Thanks, but I was actually asking about the links that OEM has in the email content sent out as part of a notification. (So you can click the link in the notification and it takes you to the appropriate spot in the Grid console). I've since heard from Oracle support that modifying these embedded links to use the load balanced hostname (rather than the individual OMS hostname) is not possible and is something they say they're working on for 11g.

Cisco 886VA - Multiple PPPoE Line Load Balancing

Dear Cisco Community,
due to the need of increased bandwidth a customer ordered three ADSL6000/576Kbit lines from the same ISP. Dial-in is done with PPPoE and the IP is not static.
- Is it possible to load balance between the three ISP lines with this router as the Cisco 886VA-K9 (Advanced IP Services) doesnt support PFR/OER I want to load balance per session, meaning each TCP session takes the same path, the next TCP session takes second path, next TCP session takes third path, then first path again and so on.
- I did read the tutorials avaiable, but they don't discuss how the lines are used in round-robin fashion, just how to distribute different traffic on different lines. (https://supportforums.cisco.com/document/32186/dual-internet-links-nating-pbr-and-ip-sla?page=1) or (http://www.cisco.com/c/en/us/support/docs/ip/network-address-translation-nat/100658-ios-nat-load-balancing-2isp.html)
- How would you solve this challenge?
Relevant config so far:
vlan 1
name #LAN#
vlan 2
name #WAN-Uplink1#
vlan 3
name #WAN-Uplink2#
interface FastEthernet0
description #LAN#
switchport access vlan 1
interface FastEthernet2
description #WAN-Uplink1#
switchport access vlan 2
no ip address
pppoe enable
pppoe-client dial-pool-number 20
interface FastEthernet3
description #WAN-Uplink2#
switchport access vlan 3
no ip address
pppoe enable
pppoe-client dial-pool-number 30
interface ATM0
description #WAN-Uplink3#
no ip address
logging event atm pvc state
logging event atm pvc autoppp
logging event subif-link-status
no atm ilmi-keepalive
no ip redirects
no ip unreachables
no ip proxy-arp
dsl enable-training-log delay 0
dsl bitswap both
interface ATM0.1 point-to-point
bandwidth 550
bandwidth receive 6000
pvc pvc 1/32
pppoe enable
pppoe-client dial-pool-number 10
vbr-nrt 500 500 1
service-policy out WAN-Control1-Parent
interface Vlan1
description #LAN#
ip address 172.16.1.1 255.255.255.0
ip nat inside
ip virtual-reassembly in
interface Dialer1
description #WAN-Dialer1#
bandwidth 550
bandwidth receive 6000
ip address negotiated
ip mtu 1492
ip nat outside
ip virtual-reassembly in
encapsulation ppp
ip tcp adjust-mss 1452
dialer pool 20
dialer idle-timeout 0
ppp authentication chap pap callin
ppp chap hostname XXX
ppp chap password XXX
ppp pap sent-username XXX
ppp ipcp dns request accept
ppp ipcp route default
ppp ipcp address accept
no cdp enable
service-policy output WAN-Control2-Parent
interface Dialer2
description #WAN-Dialer2#
bandwidth 550
bandwidth receive 6000
ip address negotiated
ip mtu 1492
ip nat outside
ip virtual-reassembly in
encapsulation ppp
ip tcp adjust-mss 1452
dialer pool 30
dialer idle-timeout 0
ppp authentication chap pap callin
ppp chap hostname XXX
ppp chap password XXX
ppp pap sent-username XXXX
ppp ipcp dns request accept
ppp ipcp route default
ppp ipcp address accept
no cdp enable
service-policy output WAN-Control3-Parent
interface Dialer3
description #WAN-Dialer3-ATM#
bandwidth 550
bandwidth receive 6000
ip address negotiated
ip mtu 1492
ip nat outside
ip virtual-reassembly in
encapsulation ppp
ip tcp adjust-mss 1452
dialer pool 10
dialer idle-timeout 0
ppp authentication chap pap callin
ppp chap hostname XXX
ppp chap password 7 XXX
ppp pap sent-username xxx
ppp ipcp dns request accept
ppp ipcp route default
ppp ipcp address accept
no cdp enable
ip nat inside source route-map ISP1 interface Dialer1 overload
ip nat inside source route-map ISP2 interface Dialer2 overload
ip nat inside source route-map ISP3 interface Dialer3 overload
route-map ISP1 permit 10
match ip address 100
match interface Dialer1
route-map ISP2 permit 10
match ip address 100
match interface Dialer2
route-map ISP3 permit 10
match ip address 100
match interface Dialer3
access-list 100 remark #NAT-LIST#
access-list 100 permit ip 172.16.1.0 0.0.0.255 any
Thank you for helping.

Hey there,
I managed to fulfill my requirement..
If its a cluster on same machine or across machines, this should work
1. Login to machine, cd $DOMAIN_HOME
2. mkdir -p Apex_lsn_config/AdminServer Apex_lsn_config/<MS1> Apex_lsn_config/<MS2> # MS1 and MS2 are the Managed Server names as appropriate
#If you are planning for cluster spawning MS's across machines, make sure you create the dir's on step 2 for each machine respectively. (in my case $DOMAIN_HOME is not shared)
3. Copy apex-config.xml from the /tmp/apex or whatever location you have it currently to Apex_lsn_config/<MS1> Apex_lsn_config/<MS2>
4. cd $DOMAIN_HOME/bin; cp -p SetDomainEnv.sh SetDomainEnv.sh.orig #Backup the file
5. Append -Djava.io.tmpdir in SetDomainEnv.sh as below for JAVA_OPTIONS # Do it on both machine if you are not sharing DOMAIN_HOME and planning cluster across machines
-Djava.io.tmpdir=$DOMAIN_HOME/APEX_CONFIG/${SERVER_NAME}
Hint: Search for "iterativeDev" and append the same line with -Djava.jo.tmpdir
6. Modify "java.io.tmpdir" from the web.xml file of apex.war as below and re-deploy the war
<context-param>
<param-name>config.dir</param-name>
<param-value>${java.io.tmpdir}</param-value>
</context-param>
7. Bounce Weblogic Admin and Manged Servers. Make sure to tail the Managed Server log to see apex-config.xml is picked from the new location.
8. Brew a Coffee for yourself :)
- You find the instructions on creating a cluster from weblogic documentation, the steps mentioned above are only to overcome the bdb locking issue whilst creating a cluster.
Did it help?
Edited by: Oratime on Mar 25, 2013 2:44 AM

WLC Load Balancing Threshold

I am trying to understand how the load balancing threshold is calculated but I am finding conflicting information, even withing Cisco's own documentation. I would be grateful if anyone could help.
Cisco's latest Wireless LAN Controller Configuration Guide for software release 7.0.116.0 (April 2011) contains the following information for configuring Wireless > Advanced > Load Balancing Page (emphasis mine):
In the Client Window Size text box, enter a value between 1 and 20. The window size becomes part of the algorithm that determines whether an access point is too heavily loaded to accept more client associations:
load-balancing window + client associations on AP with highest load = load-balancing threshold
In the group of access points accessible to a client device, each access point has a different number of client associations. The access point with the lowest number of clients has the lightest load. The client window size plus the number of clients on the access point with the lightest load forms the threshold. Access points with more client associations than this threshold is considered busy, and clients can associate only to access points with client counts lower than the threshold.
Option 1
The formula shown is correct (load-balancing window + client associations on AP with highest load = load-balancing threshold). If so, this would mean that if you had a window size of 5 and the AP with the highest load at the time of calculation was 15, the threshold would be 18. However, as no APs have 18 associations then this threshold would never be reached. Even if an AP reach 18 associations, the next client trying to associate would trigger another calculation for the threshold which would be 21 (3 + 18) and so still, this threshold would never be hit.
Option 2
The description in the paragraph below is correct (The access point with the lowest number of clients has the lightest load. The client window size plus the number of clients on the access point with the lightest load forms the threshold). This sounds much more sensible to me. In this case, the window size was 3 and the AP with the lowest number of associations already had 7 clients associated, the load balancing threshold would be 10 i.e. no load balancing would occur until a client tried to associate with an AP which already had at least 10 clients associated.
Option 3
I have seen many descriptions on forums etc of the load balancing threshold being essentially the Client window size, i.e. if the client window size is 3 then load balancing will kick in when a client tries to associate to an AP with at least 3 clients already associated. This doesnt match the above documentation unless the AP with the least number of clients associated doesnt have any associated clients i.e. 0 clients.
Questions
I think Option 2 is the correct description of load balancing and the formula given stating use of the AP with the highest load is a typo (albeit still not corrected in the latest documentation). Am I correct?
The problem with using the option 2 method of calculating the load threshold is that you will be unnecessarily performing load balancing in an environment where some of your APs do actually have zero clients associated, unless you set the window size to somehing close to 10.
I read here http://www.perihel.at/wlan/wlan-wlc.html#aggressive-load-balancing that when calculating the load threshold, it only accounts for the 8 'best' APs for a given client. In other words, if you have 60 APs on your campus but only 20 are visible to the client, the controller will only perform its load threshold calculations bases on the 8 APs which have the best signal to the client. This would ,ake sense as there is no point setting a load threshold based on the lightest loaded AP which is not even within 'reach' of the client. Is this correct as I can not find any other documentation which supports this?
Thanks in advance for your help with this.

Interesting, the config guide contradicts itself in the same paragraph.....    I thought maybe we had two different documents with different explanations. I don't see any open documentation bugs asking to correct this, but I swear I've heard discussion on this in the past.......
First off: Option #3 was the "old way". I think it changed in 6.0.    If you had a threshold of 5, then as soon as you had 5 clients on an AP it would reject the association (3 times and then let them on the 4th attempt). Now its a sliding window/scale.
Option #1 I think is completely wrong. As you described, how in the world would you ever surpass the threshold if the highest AP + the window is what you have to beat to load-balance....?    RIght, that just doesn't make any sense to me.....
Option #2, the way you explain it is correct to my understanding...
Your question #3 is also correct (not sure if it is Top 8 or based on an RSSI threshold though.)
The idea is that you don't want some AP in a remote office with 0 clients being your starting point.   So I believe that it is based on the top X candidate for your client.    If your client has 4 viable candidates (lets just say -70 or better), and one of those APs has 5 clients and the rest have 15, I'd expect loadbalancing to try to get you to the 5 client AP if your window size was ~10...... something like that anyhow...

Aggressive Load Balancing Per SSI

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