Wireless Access Point problem please help/advice

[shirzay]

We have a 4 wireless Access Points in our science department, one in each classroom the brand of the access points are Planet. We have 18 laptops that students use for each lesson to connect to the network wirelessly. The AP are configured to pick up IP from our PDC and WPA PSK security is set. But the laptops are connecting very intermittently and sometimes they search for IP for minutes and eventuly say SLOW OR NO CONNECTIVITY. We have done the following:

 

, Laptops are updated with all Microsoft updates

, The network cards of all 18 laptops are upgraded (from the manufacturers websit Intel)

, Planet technical support were of no help

, Firmware updates were not authorized by the Planet, they think the firmware is up to date

I strongly believe that these AP are total rubbish and there is something wrong with hardware. We have now called our contractors who initially installed the APs to change it with a stable brand but they say they wont change it and blames our configuration (but how difficult is configuring an AP ?). but please Advice me of anything that you think i should do that you think i missed to do.

Also we are going to install another 8 AP, please advice me on what brand should we go for, that you think is good and will support 20 clients to connect to the AP in the same time.

thanks

[mattx]

I have not heard of this make of AP I have to say but there is a great deal of things to consider when clients connect to APs:

 

Profiles - roaming / mandatory / local ? If roaming then possible bottle neck with 20 clients all logging on at the same time.

AV Updates - what AV are you using ? AV products tend to update when they first appear on the network that day.

WSUS updates. [ I have a seperate group just for laptops which I only update during school holidays ]

Login scripts. Doing anything fancy thats taking up time ?

Wireless login Authentician - whats taking care of that ?

Proset software installed ? [ if intel chipsets ] - I let windows control the wireless side of things on our laptops - much better in my opinion.

20 Laptops all logging in to one AP at the same time ? - If you are lucky they will be connecting at 36meg [ if a 54 meg wireless link ] You do the math !!

I get twitchy when there are more than 10 going into an access point - hence I have placed more than one AP in rooms in which I know there will be heavy usage. We are lucky and use a managed solution so I have turned on the load balancing option.

 

First thing I would try would be one laptop on the wireless network - start a ping [ after you have connected ] and walk around to see the signal levels and make note of any black spots. If all is ok, fire off another laptop, then another etc etc. But of course the real test is launching a load of laptops at the same time.

 

Also check the driver setting on the wireless network card - if they are intel there should be more options, like turning roaming up so the card monitors to see its connected to the best AP. Also I turn the power up to max [ some cards again to save battery life have the setting to average ] I also turn off any screen savers, APM, Hibernation, Sleep etc etc. This helps on our setup, you never know, it may do on yours.

Is your wireless network managed ? If so you should be able to force clients to a particlar AP to help the load aspect.

Anyway - food for thought some of my ideas may help - hopefully !!

 

In regards to what to go for in the future - managed all the way if you can afford it - we use Aruba kit. After a bit of a dodgy start it works a treat.

 

Sorry about my spellings btw - typing it whilst trying to get my kids to stop bugging me and get to sleep !!

[strawberry]

4 access points in science block?

 

large wad of money on it being overlapping channels on your waps.

 

download netstumbler onto a laptop and move around the school, if you can see more and 3 access points at any time you definately have signal overlap. think of it like tv channels, if you have 3 signals on one channel it wont work.

[richard.thomas]

As strawberry said, make sure the AP's are on different channels if they're all close to each other.

 

As for other makes of AP, we use 3com and haven't had an issue yet

[shirzay]

I have not heard of this make of AP I have to say but there is a great deal of things to consider when clients connect to APs:

 

Profiles - roaming / mandatory / local ? If roaming then possible bottle neck with 20 clients all logging on at the same time.

AV Updates - what AV are you using ? AV products tend to update when they first appear on the network that day.

WSUS updates. [ I have a seperate group just for laptops which I only update during school holidays ]

Login scripts. Doing anything fancy thats taking up time ?

Wireless login Authentician - whats taking care of that ?

Proset software installed ? [ if intel chipsets ] - I let windows control the wireless side of things on our laptops - much better in my opinion.

20 Laptops all logging in to one AP at the same time ? - If you are lucky they will be connecting at 36meg [ if a 54 meg wireless link ] You do the math !!

I get twitchy when there are more than 10 going into an access point - hence I have placed more than one AP in rooms in which I know there will be heavy usage. We are lucky and use a managed solution so I have turned on the load balancing option.

 

First thing I would try would be one laptop on the wireless network - start a ping [ after you have connected ] and walk around to see the signal levels and make note of any black spots. If all is ok, fire off another laptop, then another etc etc. But of course the real test is launching a load of laptops at the same time.

 

Also check the driver setting on the wireless network card - if they are intel there should be more options, like turning roaming up so the card monitors to see its connected to the best AP. Also I turn the power up to max [ some cards again to save battery life have the setting to average ] I also turn off any screen savers, APM, Hibernation, Sleep etc etc. This helps on our setup, you never know, it may do on yours.

Is your wireless network managed ? If so you should be able to force clients to a particlar AP to help the load aspect.

Anyway - food for thought some of my ideas may help - hopefully !!

 

In regards to what to go for in the future - managed all the way if you can afford it - we use Aruba kit. After a bit of a dodgy start it works a treat.

 

Sorry about my spellings btw - typing it whilst trying to get my kids to stop bugging me and get to sleep !!

 

thans for the lovely tips. here are the ansowers to your points that may help in further suggestions:

one AP is installed in each room, and there is only a wall or 2 between these AP they are quite close to each other and more than 1 AP can be seen with good signal in each room (even when we manualy try to devide laptops between 2 AP the same problem). We dont have mandatory profiles, the script that runs while logging in is very simple it is just to map 3 network drives to the student profile. we use Sophos as our AV and it updates on logon. We do have WSUS but the time is set to pick up updates at 1 pm. We use the WPA-PSK authentication (we dont have a managed wireless network, we just have a bunch of APs hence i can not force load balancing). We use Windows to control our wireless connectivity. we have configured each AP with a diff channel the problem is still there.

So do you think the only stable solution will be managed envoirnment? if so I called Netgear and thiir solutions is £1000 for the managing device and £70 for each AP. do you think it is reasonable?

But i always thaught that most schools are using non managed wirelss networks how does it work for them?

thanks

[strawberry]

togo into a little more depth about ap channels.

 

Althought there are 11 channels (13 on some) There are only 3 that truely dont overlap, 1, 6 and 11. You will also find that if you set the ap to have 13 channels that some clients simply wont pick up the signal past 11.

[shirzay]

togo into a little more depth about ap channels.

 

Althought there are 11 channels (13 on some) There are only 3 that truely dont overlap, 1, 6 and 11. You will also find that if you set the ap to have 13 channels that some clients simply wont pick up the signal past 11.

 

Yes we only use 1, 6 and 11.

[sahmeepee]

Another thing to consider with wireless signals is that the clients make the effective signal range greater - a laptop connected on channel 1 on the very edge of the range of your channel 1 AP will be transmitting at full strength from that location and potentially causing interference with laptops talking on the same channel to a different AP.

 

Cisco have a good document on this topic - Wireless channel deployment issues

[z4ydi]

We have now told our contractors to take thier access points away, and we decided to go for a Managed Wirelss solution. Could someone please let me know which one of the Managed Wireless solutions are the best and good in price.

[ricki]

Would you try something for me before spending a load on money?

 

Turn off all the access points except the one in the room that you are working.

 

Then turn on a machine in that room and see if the problem goes away.

 

If it does then the access points are conflicting with each other.

 

Second buy a different wifi card of a different make than whats in the laptop and install it in one of the laptops and set up the encryption. Make sure that you have the same spec of card as the router. See if that solves the problem.

 

Third do that access points have turbo boost speed enabled or something similar. I have found that when it is some cards dont work well with it.

 

Forth does the access point have ports in the back of it? If it does try hardwiring the laptop in a port to see if the acess point is connecting to the network correctly.

 

Fifth Does this only happen at specific times of the day or all the time. I used to have a problem during dinner when they used a microwave cooker.

 

Sixth Have a look at the spec of the laptop. We have loads that are old and it takes them ages to do anything. I cured one set by increasing the ram in the set.

 

Seventh Do you use ghost ris of something else on the network that uses loads of bandwidth. This kills wifi dead or near as dam it.

 

Eighth Install netstumbler and do a site survey. I have a look to see if someone else has an access point thats on the same channel or nearly the same channel that you are using. I had a problem with a local house that set up an access point and they placed a huge arial on it and were drowning out our signal.

 

Only a few ideas

 

Richard

[jjx]

Just for grins, if you're getting little or no connectivity and the APs are passing through DHCP? (Is that correct?)

 

If so, I would enable the DHCP server on a test AP (choose a scope that will give you access to the network but won't overlap what's already there).

 

If it's a signal issue, there are several other things you can try.

 

(Also FYI, channels 1, 6 and 11 are not the only ones that don't overlap, they're the choices that give you the most selection (3) that don't overlap).

 

-jj