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Number of Clients Per Access Point on Single Band 2.4ghz

Hi there,

 

So although Im not actually using cisco access points, i thought this might be the best place to get some confirmation.

 

16 Extreme Network 4511 AP single band radio , can do either 2.4 or 5.0ghz. -they have a virtual master and all use the same config they are

All connected via POE to an Extreme Networks 450e POE switch via cat6 -

The switch has 6 uplinks  (lag -lacp) to the main hp switch which is then connected to our sonicwall firewall, and then out over a 100mb dedicated line.

The 100mb line is shared with the house (wired) network.

On the switch I run port utilization and monitor the throughput on all the ports, none have ever gone above 40%, most  of the time they run around 3-5%

 

We have 16 single band 2.4ghz APS spread out over 2 floors, at least 6 of these are in audio rooms as the rooms have lead in the walls for noise dampening etc.

Each AP is on either channel 1,6,11.

In general when its quiet to average use (around 60 clients in house) it handles ok,

however when we start hitting 80-90 clients and some APs have up to 8 -10 clients in them we start getting big slowdown.

The majority of the time rebooting the access point in particular room fixes this, but its only temporary.

 

We have Client Load balancing enforced to 1mb up and down, ,and have limited each access point to 20 clients max.

In the logs I have noticed that when these begin to fail, clients get error handshakes going on, however Utilization on the access point never looks like its out of control, and on the switch side it never even reaches 10%

 

When we get the internet slowdown, i know its not at the main internet level, I have one machine hardwired into the main AP point and i have one machine on the house network.

The house network machine can  browse and playback/stream video fine, however at the same time the machine on the wireless shows significant slowdown when browsing the web.

The issue is defiantly on the wireless side, If i plug a machine directly into the switch and assign it a static ip, i do not get slowdown, so this is happening before it reaches the poe switch.

So my question is - is it number of clients connecting and streaming, is there a number of clients i should limit each ap too, 

the clients need to be able to play back quicktimes and so forth for work so i cannot limit the bandwidth too much.

Would switching the APs to 5ghz help? or would adding a second ap in the same area but putting it on 5ghz help?

Eventually in August we are hoping to get a secondary internet line in, FIOS business 300/100, would having the wireless on this help? or is it just a AP bandwidth thing?

My only explanation is that each actual AP is getting congested with commands and that creates the slowdown,

 

any help , thoughts would be great.

thanks

 

Brian

 

 

2 REPLIES
Cisco Employee

Though this sounds very

Though this sounds very specific to the AP and its scalability and should be confirmed for best practices in deployment with the AP vendor. The infrastructure with numbers look great and ideally should not have any problems with 8-10 clients.

One suggestion is to try using 5 Ghz channel which has more number of non-overlapping channels and see the results (I guess easy to deploy and test option).

If you have any Network Management Application, manage your switch and Wireless infrastructure to see if there is any Utilization issues as per it.

-Thanks

Vinod

-Thanks Vinod **Rating Encourages contributors, and its really free. **
Hall of Fame Super Gold

The house network machine can

The house network machine can  browse and playback/stream video fine, however at the same time the machine on the wireless shows significant slowdown when browsing the web.

The issue is defiantly on the wireless side, If i plug a machine directly into the switch and assign it a static ip, i do not get slowdown, so this is happening before it reaches the poe switch.

So many factors affect the way to stream data up and down wireless.  Sure, I have seen >40 clients on 802.11a AND 802.11b radio of a single 1140 AP.  But this is not good.  Why?  Because wireless is a very "noisy" environment.  When one talks, everyone else has to stop, listen and waits for their turn.  The > 80 wireless clients connected to the 1140 AP had a detected maximum speed of 11 Mbps and they couldn't get any higher than that.  They couldn't get any lower than 11 Mbps because I've disabled lower data rates.   

 

You said you hard-code the channels to 1, 6 and 11 but what is the co-channel interferrence like in your wireless environment?  

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