Network and Classroom Management Thread, Which WAPs? in Technical; We have 2 sets of wireless laptops (16 x 2) which access the network by 2 WAPs each (Netgear WG602 ...
3rd March 2008, 10:51 AM #1
We have 2 sets of wireless laptops (16 x 2) which access the network by 2 WAPs each (Netgear WG602 and Proxim Orinoco). Each pair are on two different channels and half the laptops are 'pointing' at each WAP
The speed etc is, and always has been, appalling and the laptops are nearly unuseable.
I have recently upgraded the switches on the network and now we have a decent backbone but this hasn't improved anything (to be fair the WAPs are not connected straight to the backbone but via a 100 switch)
I need to know why nothing works - the school next door has the same system on the computers (schoolcare) and their wireless works fine, so I don't think is that slowing it down too much.
What can I do to improve the situation? We don't have much money so an expensive solution is not doable - and I can't get a handle on why everything is SO bad as it is ( all put in before my time here). I know there are threads about which WAPs are good but I don't know which would be best for my network! All advice gratefully received!
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3rd March 2008, 11:28 AM #2
At the main site I work at with have used cisco Aironet kit, which has been very reliable with aroun 120 wireless laptops in the school, however at over £300 per ap this is not a cheap solution.
At some of our smaller supported schools we have used the Netgear WG302 points, which are about £110 each i think. These have been excellent, and 1 ap happily supporting 20 laptops at once. - Note we dont have roaming profiles or too much else happening at logon, but 20 laptops will happily browse the net at the same time.
The netgear wg602 you currently use does look more like a home access point, in the past we have tried cheap d-link points and found them to be very unreliable for anything more than 1 or 2 laptops.
Only other things you might want to chech for your existing setup are:
Do you have large roaming profiles, redirected folders etc which will use up bandwidth?
Which type of encryption are you using? from experience some points work better with certain types than others.
Are there any 802.11B devices still around the school and in use? try setting the access points to 802.11G only to see if that makes a difference.
Is windows update enabled on the laptops? If so disable it - 16 laptops all downloading updates will completely kill a wireless network!
3rd March 2008, 11:32 AM #3
thanks for that. Yes, we do have roaming profiles and they are quite large. Maybe that is the problem?
One of the pairs of WAPs aren't encrypted at all but no faster (the proxims)
No, the laptops don't run windows update
We have no other 802.11B devices in the school. How do I set the access points to 802.11G and why would that make a difference?
3rd March 2008, 11:44 AM #4
802.11g runs at a maximum 54Mbps, 802.11b runs at a maximum of 11Mpbs.
Provided your AP's support 802.11g, you should be able to set what they run at through the WebUI.
3rd March 2008, 11:46 AM #5
Roaming profiles could be a problem, although are things still slow once everyone has finished logging on?
If you have no B devices around then setting to G only wont make any difference. B runs at 11mbit as opposed to 54mbit for G, if you get 1 B device on the network, everything off that point runs at 11mbit, regardless of if its B or G. Someone on here gave the technical explination for this a little while ago, cant remember what it is now!
What model network cards do you have in the laptops?
At the moment i'm thinking it may be new access point time! - When we first moved to the netgears, we managed to speak to a local supplier and get them to lend us one for testing before we purchased them, maybe this is something you could try?
3rd March 2008, 11:51 AM #6
I would look at your profiles as you've said.
Have a look at the sizes for a group of kids that login.
You could then try 16 kids logging in with a new account that has a mandatory profile and see what thay acheives.
Have you run something like netstumbler on a wireless laptop to see what other access points can be picked up where you are? it could be there are several outside ones on the same channels as yours interferring.
Have a look at WirelessMon from passmark this allows you to create your own signal strength maps.
You can try it free for 30 days after that it's $50 which is good.
5th March 2008, 09:28 AM #7
right: Netstumbler shows no issues at all
The log on is painfully slow - when logged on the speed isn't bad but the machines keep losing the network. The laptops are fairly old now - 4 and 5 years (Acer Travelmates) so they aren't brilliant but we have no money to do anything other than maybe replace the access points - but only if this will make a significant difference - which is where I started
I suppose my main point is: would better access points actually help or am I on a hiding to nothing?
I will try the kids logging on to an account with a mandatory profile and I will look into the roaming profile issue
5th March 2008, 09:46 AM #8
Originally Posted by witch
If i've read this post right. your connecting 16 laptops to an AP. 16 is too many. I would recomend 8 to 10 laptops per AP. also have you updated the AP firmware. Driver update on wireless laptops is worth a try.
5th March 2008, 12:23 PM #9
See OP - 16 laptops, 2 APs so 8 per access point.
Originally Posted by MrHappy
Have updated drivers on wireless laptops
5th March 2008, 12:30 PM #10
ooops clearly not had enough coffee whe i read the post hehehe
Originally Posted by witch
5th March 2008, 01:01 PM #11
You say netstumbler shows no issues, it won't it just shows you what access points are there.
Can you pick up any other access points in netstumbler as well as the ones you know are yours?
There could be some other sources of interference on the channels you have selected.
Trouble is the only way to find that out is to either use a spectrum analyser or just play around with channel settings.
If you feel comfortable using it and think it may help you I could loan you our wi-spy.
5th March 2008, 01:11 PM #12
Sorry, that's what I meant - netstumbler shows no access points that aren't ours.
Have played around with channel settings and it makes no diff that I can see.
Thanks for the offer.
I just don't know enough about this to know what is the best thing to do -it is really frustrating!!
5th March 2008, 05:07 PM #13
i would do some basic troubleshooting...try connecting and logging onto the laptops one by one, to determine whether if the times deteriotates once it reaches a certain number of users....if you get poor logon times with just one or two laptops connected check the AP's webgui to check that everything as it should be, and make sure the AP is connecting to the switch at the speed it should be.
Originally Posted by witch
If the slow logon times happen once it hits a number of connected laptops again check the ap webgui's to make sure laptops are connecting to the right ap....
alternatively it may be a laptop and user specific issue, as someone has said is it roaming profile related ? have you tried looking on to the network as a user with no roaming profile, is it any different ?
There could be several processes you need to go through before you nail the problem(s).......have faith in the network troubleshooting process. If necessary restart everything, log into everything (AP, switch, laptops) to see if you notice something peculiar.
As for choosing the right ap, we use Cisco aironet 1240AG's with some fancy antennaes......they're fab. People have no idea where the AP's are, i've installed into suspended ceiling with the white omni antennaes blending seamlessly with the white ceiling tiles.
I also get much better coverage with .11a rather than .g in our building. If you go with the cisco's you've got a number of managed system choices at reasonable cost for a small environment.
Last edited by torledo; 5th March 2008 at 05:13 PM.
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