Beginner Capacity Question.

Unanswered Question

Good morning everyone, I work for a small private school in Ohio.  We have a CISCO Catalyst 3560G for setting up our VLAN's.  I have two VLANS set up for my wireless network which is on a CISCO 2106 Wireless Controller with six access points.  The wireless controller has two different wireless networks programmed into it...called BLUE and RED.

I have steel buildings which limit access to the AP's between the wings in our School.  I have one wing with two AP with very limited wireless use.  The second wing has three AP and will have MOST of the use.  The third access point is in the GYM and that also has limited use.

My Question:  Will the three AP in the area with the MOST traffic be sufficient to handle 260 laptops? Our network has a dark fiber backbone and we have a 5MB pipeline coming in from time warner.

Thanks.  Andrew

I have this problem too.
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George Stefanick Thu, 02/04/2010 - 17:23

Hello Techdesk,

I would be concerned and here is why. Cisco recommends 25 or so clients per access point. Of cource you can associate mnay more then this number up to 1024 in fact. What type of access points do you have and do they have both 802.11a and 802.11g radios?

Leo Laohoo Thu, 02/04/2010 - 18:17

Hi Andrew,

It's good that you ask.  Wireless transmission behaves exactly like a wired hub:  One talks and everyone listens.  So if you have 260 laptops talking simultaneously to ONE AP (ok, ok, ok let's say half) expect to see delays and latency.

Your options are to add a few more AP's, in my view about 7 - 8 and you can configure the AP's to accept no more than 30, for example.

Another issue is the signal distribution.  This is very important when the AP's are not deployed evenly and some AP's may have alot of clients and some don't.

jwarner Sun, 02/07/2010 - 12:01

The job of the network engineer is to move bottlenecks around.

In this case, the important question may be: "Is a 5 Mb/s pipe from Time Warner sufficient for

260 laptops?"  If you have local data sources that are heavily used, your internal traffic

could exceed your external traffic.  But many schools do not have internal data sources.

Or their internal web servers have static pages with e.g. the lunch menu that, while

important, don't generate a lot of traffic.

You should haul your laptop into the Gym in the middle of the day.  If the network

in the 3-AP building is slow _and_ it is slow in the gym as well, your backbone is


If your real intention is to build the case for a Time Warner speed bump, I think you're

on the right path.  If the budget permits, you can move the bottleneck to the APs, and

then work on that.  I doubt the APs will be your bottleneck today.


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