When "b" users join the "g" game, Cisco says that g throughput will drop to 8 Mbps max 
(true throughput, after the half duplex affect of wireless) because CTS/RTS is invoked 
when b is present, where as it's not when g is  the only technology in use.



>>> [EMAIL PROTECTED] 03/28/04 09:04AM >>>
We are now in the process of upgrading from 802.11b to 802.11g in our
Cisco 1200's. Here's what I see so far:

In 802.11g, if there are 5 "g" clients buzzing along at 54MB/s and one
"b" client walks in the room and connects at 11MB/s, all other clients
drop to 11MB/s *during actual network activity from the "b" client*. It
appears that when the "b" client is idle or disassociates, the "g"
clients enjoy the higher bandwidth again.

Not sure if this typical of what I can expect to see throughout the
campus as I install more "g" radios, but this is what we see in our test
environment.

I realize that I can deny connections to the AP at speeds of 11MB/s or
less to get "pure g", but we need the mixture.

Philippe Hanset wrote:

> Eric,
>
>
> You can limit yourself which connection you allow,
> "transmit rate".
> But bare in mind that a person joining an AP at 1 Mbps
> will slow down all the other ones!
> So it's not a common denominator effect but a
> queuing effect.
> When you mix 802.11g and b it gets even worse.
>
> Philippe Hanset
> U of Tennessee
>
> On Fri, 26 Mar 2004, Eric T. Barnett wrote:
>
>
>>Hello,
>>
>>
>>
>>I'm new to the listserv.  I read somewhere that the AP's maximum speed
>>for all clients is equal to the lowest connected speed, i.e. if one
>>person connects at 1Mb then all users on that AP connect at 1Mb.  Is
>>this true?  If so, that would explain why some of my clients end up with
>>low speeds and great signal strength.  If this is vendor specific, we
>>are using Cisco 350 and 1200's on campus.
>>
>>
>>
>>Thanks,
>>
>>
>>
>>Eric Barnett, CCNA
>>
>>Wireless Administrator
>>
>>Information and Technology Services
>>
>>Arkansas State University
>>
>>870-972-3033
>>
>>
>>
>>
>>**********
>>Participation and subscription information for this EDUCAUSE Constituent Group 
>>discussion list can be found at http://www.educause.edu/cg/.
>>
>
>
> **********
> Participation and subscription information for this EDUCAUSE Constituent Group 
> discussion list can be found at http://www.educause.edu/cg/.

--
***************************************************************
Michael Dickson                         Phone: 413-545-9639
Network Analyst                         Fax:   413-545-3203
University of Massachusetts     Email: [EMAIL PROTECTED] 
Network Systems and Services
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