what is the best data rate to set?

[hassan_si]

what is the best data rate to set in high density client environment and disabling 802.11b clients.

[Leo Laohoo]

Disable 1, 2, 5.5, 11 Mbps disabled 802.11b data rates.

Some would even recommend you disable up to 9 Mbps and make 12 Mbps as Mandatory.

Take note that by doing something like this you get the following effects:

1.  You are making your wireless signal footprint SMALLER;

2.  Not all clients will support 802.11 g data rates.  There are some clients (such as barcode scanners) that will only support 1 or 2 Mbps data rates.

3.  Disabling data rates alone does not fix "channel interference".  It simply makes your footprint smaller and therefore allowing the channels to "breathe".

[Amjad Abdullah]

Salam Mohammed,

Here is the document taht you'll find very handy:

Cisco High Density Wireless LAN Design Guide

http://tiny.cc/erqbfw

HTH

Amjad

[hassan_si]

Walaikum salam,

Thanks for the info.

I have done the data rate settings as below on my controller

Data Rates**

1 Mbps  Disabled 
2 Mbps  Disabled 
5.5 Mbps Disabled 
6 Mbps  Disabled 
9 Mbps  Disabled 
11 Mbps Disabled 
12 Mbps Mandatory 
18 Mbps  Supported
24 Mbps  Supported  
36 Mbps  Supported  
48 Mbps  Supported  
54 Mbps  Supported  

But still I could see som 802.11b clients are probing on my AP.

Any reason?

Thanks,

[Leo Laohoo]

But still I could see som 802.11b clients are probing on my AP.

Probing?

Probing means the wireless NICs are TRYING to get into your network and they don't have the correct credentials to authenticate to your network.

[hassan_si]

Thanks for the info

My understanding is that in b/g mix environment if 802.11b clients trying to connect, then AP will reduce the throughput to 13 Mbps.

Now in my environment I could see the 802.11b clients are probing but unable to authenticate. Will this reduce the throughput to 13 Mbps?

[Leo Laohoo]

Now in my environment I could see the 802.11b clients are probing but unable to authenticate. Will this reduce the throughput to 13 Mbps?

Again, probing means a client, whether it's authorized client or someone sitting in a car outside your office doing war driving, doesn't mean it's legitimate.  So take this out of your equation.

My understanding is that in b/g mix environment if 802.11b clients trying to connect, then AP will reduce the throughput to 13 Mbps.

Let's talk about a WAP and a client and nothing else, ok?

The WAP does not have the capacity to say, "Hey, I don't know you.  I don't LIKE you.  I'll let you transfer traffic up to 11 Mbps."

The decision to use which data rate is from the client.