802.11g-only network conversion

Answered Question
Feb 11th, 2009

Folks, I am making plans to convert my wireless network from 802.11b/g to 802.11g only. I've done a fair amount of research and have discovered that there is a 66% performance hit when running mixed b/g mode compared to a stricty .g network. This is because a .b client in the mix will drop the network into protection mode where the APs perform extra processing to make sure they do not step on the .b modulated traffic.

The performance gain is the driving factor behind this initiative. I want to keep my network out of protection mode.

Now I know that all our managed clients will support .g-only. My question here is whether anyone knows what will happen to the .g-only network if it detects neighboring business .b clients probing. We are located in a dense urban location. So will these neighboring .b clients drop my .g-only network into protection mode if APs hear these .b modulated probes/beacons even if these .b clients do not associate?

If that is the case, then it may not be worth converting to .g-only, if our neighbors can still impact the performance of our network in that way.

Any thoughts are appreciated.

Regards

I have this problem too.
0 votes
Correct Answer by jeff.kish about 7 years 11 months ago

By disabling 802.11b, you'll be disabling the 1, 2, 5.5, and 11Mbps data rates. These are the rates at which 802.11b clients probe, so your APs will be immune to such probing.

Best of luck! It's exciting that you get to disable 802.11b, I see too many businesses that don't want to do so for one reason or another. You should enjoy some pretty fast rates in a pure G environment.

Jeff

Correct Answer by jwadleigh about 7 years 11 months ago

Your neighbors will not be able to enable protection mode on your network. If you have your network in g-only mode, it will completely ignore non-g traffic.

Further, even without enabling g-only mode, the AP only goes into protection mode when it negotiates association with a b client, which wouldn't happen if your neighbor is not probing the appropriate SSID.

Hope this helps.

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Correct Answer
jwadleigh Wed, 02/11/2009 - 12:03

Your neighbors will not be able to enable protection mode on your network. If you have your network in g-only mode, it will completely ignore non-g traffic.

Further, even without enabling g-only mode, the AP only goes into protection mode when it negotiates association with a b client, which wouldn't happen if your neighbor is not probing the appropriate SSID.

Hope this helps.

Correct Answer
jeff.kish Wed, 02/11/2009 - 12:04

By disabling 802.11b, you'll be disabling the 1, 2, 5.5, and 11Mbps data rates. These are the rates at which 802.11b clients probe, so your APs will be immune to such probing.

Best of luck! It's exciting that you get to disable 802.11b, I see too many businesses that don't want to do so for one reason or another. You should enjoy some pretty fast rates in a pure G environment.

Jeff

c.fuller Wed, 02/11/2009 - 12:44

Thanks guys. I was hoping this was the case.

So it sounds like even if I broadcast an SSID on my g-only network (i.e my guest network) b-only neighbors still won't be able to associate. It's probes will be ignored. This was another concern I had.

I'm looking forward to observing the actual throughput improvement once complete.

jeff.kish Wed, 02/11/2009 - 14:33

Thanks for the feedback :D

You're actually quite wise to be asking about probes. A lot of people think their network is all-G just because their clients are all G clients. Especially for someone like you with nearby businesses, you always need to be wary of 802.11b probes.

I'll admit that I've not heard 66% improvement, but I think 40-50% is common. Either way, it's a vast improvement.

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