Concurrent users per 3600?

[tahequivoice]

This is one I am having a hard time finding an answer for.  How many clients can a 3600 AP support?  For 150 clients on one of these, what would the throughput be for each client?

If my calculations are correct, the device can deliver 420 Mbps, which gives each client roughly 2.8Mbps. Is this correct?

[Stephen Rodriguez]

Yes and no.  Take a look at the Miercom Test that was done.  The answer is, it depends.  What type of client is connecting, what that client is doing, and how many other clients are wanting to do the same thing.

http://www.cisco.com/en/US/prod/collateral/wireless/ps5678/ps11983/miercom_report_3_12.pdf

HTH,
Steve

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[tahequivoice]

If I were to knock the speeds down to say the 11Mbps range on the WLC, would that allow more users on the AP?  If the max someone can use is 11 Mbps,  so in theory, 38 users can have 11 Mbps connections. 

Another thing, are the 3600's connected to a WLC smart enough to load balance the clients when the AP's are close to each other?  How do they do this for a large hall that seats several hundred?

[blakekrone]

Lowering the speeds is counterintuitive. Higher data rates allow the client to get on and off the "wire" quicker allowing for better performance and could allow for more connections possibly. If you only support lower data rates it takes the client longer to transmit their packets thus holding up the RF longer causing clients to have to wait to transmit.

[tahequivoice]

Well here is the situation, customer has 6 1250 AP's currently on a WLC. The clients are heavy bandwidth hogs with file transfers, and data manipulation, not sure what exactly they do, but they saturate the wireless, and have a lot of employees who are working exclusively on the wireless network as they roam the office to get their work done. They are constantly complaining about slow speeds on the wireless.  This is the environment that I need to come up with a better solution for them so they can work faster over wireless, because fixed wired is not an option.

They are moving to a new location and now is the time to build them a better network, and looking to start with 16 3600 AP's and maybe span up to 36 total. Not sure how many employees they currently have, I am working on getting that information from them.

They also use wireless phones, but for that, if they switch to A band 7925 phones, the A band can be setup exclusive for their voice.

[Stephen Rodriguez]

Another thing, are the 3600's connected to a WLC smart enough to load balance the clients when the AP's are close to each other? How do they do this for a large hall that seats several hundred?

teh WLC can try to loadbalance the clients, but it is ultimately up to the client to accept the message from the AP that says it's busy.

For the users, you might want to look at keeping the voice off of the 5GHz, and doing a 40MH channel bond.  This will allow the clients to transmit at up to 450Mbps, if they are a 3SS client.

HTH,
Steve

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[Leo Laohoo]

They are moving to a new location and now is the time to build them a better network, and looking to start with 16 3600 AP's and maybe span up to 36 total. Not sure how many employees they currently have, I am working on getting that information from them.

This is not concrete answer because we don't know what the physical environment is like.  I mean without adequate description it sounds to me that you will be deploying or you have deployed the WAPs in a large barn with no walls or cubicles and the WAPs are 10 feet from the ground.

The clients are heavy bandwidth hogs with file transfers, and data manipulation, not sure what exactly they do, but they saturate the wireless, and have a lot of employees who are working exclusively on the wireless network as they roam the office to get their work done. They are constantly complaining about slow speeds on the wireless. 

Alot of questions here:

1.  When these people complain, have they given you what signal strengths the clients are detecting the wireless signals? 2.  Are the clients running on 802.11b/g or 802.11a/n radio?

3.  Channel interferrence?

4.  WAP uplinks:  Are the uplinks GigabitEthernet?  Any signs of speed/duplex mismatch?

5.  What's the uplink to the server they access alot?   Any signs of speed/duplex mismatch?

6.  Wireless NIC clients - gosh, I can think of a number of questions here ...

[tahequivoice]

At their current location, we installed 6 1250 BG radios, 2 on each floor, and not very big rooms either. The real problem started when they decided to take one AP offline on each floor thinking that would help, but they had 45+ users on each AP then. That is where their problem started. SO in the new space, which I haven't seen yet, they are wanting to add more AP's that are capable of handling a lot of clients. They had asked if there is an AP that can do 150 clients.

We had opened a TAC case when they complained about speeds, and Tac came to the same conclusion, too many clients per AP. 

[Stephen Rodriguez]

There are no AP that can handle 150 clients, not well anyway.  Half-duplex shared media, think of the AP as a hub which it essentially is.

     The more clients you put on it, the worse the performance is going to be.  What you probably need to look at is the High Density design guidlines.

HTH,
Steve

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[Leo Laohoo]

They had asked if there is an AP that can do 150 clients.

No manufacturer will guarantee you this high amount of clients.

Like I've stated before, we need to understand the dimension of the space (l x w x h).  We also need to know how many people will be "living" in this space.  (Take that value and multiply by 2.5)

Next, you'll need to consider physically disabling the 802.11b/g radio to some of the WAPs.  Doing this has a "cost" as some clients (laptops, bar code scanners and smartphones) don't have 802.11a radios.