Wireless Networks Thread, Wireless Issue in Technical; We have just bought some laptop trolley that will hold 30 laptops in each, and got a 3com 7760 AP ...
29th January 2009, 12:23 PM #1
We have just bought some laptop trolley that will hold 30 laptops in each, and got a 3com 7760 AP for each, the laptops connect to the AP fine but for some reason every now and again, they will come up with limited connection, i restart them and they they connect again. Other times i have to turn them all on and then reboot the AP.
But even doing that does not guarantee that the next day when they turn them on they will connect again.
I hate laptops trolleys and Wireless!
29th January 2009, 02:56 PM #2
The joys of wireless!!!
Think you will find that you are running out of bandwidth with 30 laptops on one access point.
I am aware of a certain model of access points that fall over at 7 connections and the supplier of the access point has had the manufacturer test and confirm this.
Be aware that actual through put on a 54MB connection is actually about 22MB and this is being devided between 30 laptops.
Even if the the laptops are idle they still maintain a connection with the access point.
I would suggest that a maximum of 15 laptops per access point would be more ideal or a managed solution with fixed access points.
29th January 2009, 06:10 PM #3
well we have only bought 1 for each trolley as they said they could handle up to 64 i never believed it. Looked at managed solution but it was like 19k. They eventually get on but it takes a few reboots of the access point.
29th January 2009, 06:15 PM #4
We have 3 trolleys each of 15 and a cheap D-Link DWL-7100AP on each and have no problems at all as we use the 802.11a band which makes sense with our site being blanket covered on 802.11g.
What Chilbs said about the bandwidth is also true but this shouldn't stop you getting IP addresses really unless there's a device using all the juice up whilst the others are trying.
For example, if you laid all 30 out on a table and booted them all up and left them at a login screen, would all of them get an IP?
Do you have any other wireless in the area? Have you looked at interference on the channel? Are your IP's being handed out from a server via the AP?
29th January 2009, 06:35 PM #5
What are you using to allow the laptops to connect....windows wireless? I only ask because we have a similar situation and we use a third party utility that starts on boot which connects to the APs. This utility reports alot more information including what AP it is connected to including signal strength, etc...
I don't think 15 or even 30 laptops should saturate an AP by just trying to connect
29th January 2009, 06:48 PM #6
We find static IP for laptops works so much better than DHCP.
Would suggest you try to see if it helps.
30th January 2009, 10:14 AM #7
We use windows wireless to connect them, for some reason some computers connect straight away some come up with limited or no connection, i then either change the channel on the AP and it sorts it out or reboot it and it sorts it out.
If i put them all on the tables and connected them, no they wouldnt pick up an IP if i logged on as a local admin and then rebooted the AP they would all then get an IP.
We have other wireless AP around school, no idea how far they cover, i would bet they are the problem but if i turn them off you can bet someone will need the other trolley that uses them.
I hate the trolleys so much, just had the head asking about them, explained again and again but when they hear the cost they stop asking.
30th January 2009, 10:31 AM #8
Originally Posted by tomscaper
It sounds like you have had enough and if the cost is sensible then you may be able to get a manged wireless soloution in the school, or even some fat access points that work well with a large number of users.
I can gurantee both with Ruckus Wireless and would be more than happy to discuss this with you when you have the chance.
It sounds like you have looked at solutions that cost a fortune already which is something that Ruckus addresses by being very cost effective.
If the complete solution is not needed then the fat access point method would certainly get you out of a hole for now and for very little cost.
PM, email or call me I am happy to help
Also check out what other people say about Ruckus on Edugeek to see for yourself.
This is not going to cost you anything to chat about it and see if this is an option for you, if it's not then no problem.
I look forward to hearing from you.
30th January 2009, 10:33 AM #9
NightShade01: What client program are you using?
30th January 2009, 11:18 AM #10
Originally Posted by MarkPower
I have actually spoken to you and you emailed me a few quotes to pass up, but i dont think there is any budget to go ahead with anything, currently just waiting still.
For now i have decided to forget about the 3Com ones and have put two older ones in the room and they seem to be coping with the laptops far better.
I know it will still run slow but its all i have to work with right now.
30th January 2009, 11:27 AM #11
Originally Posted by tomscaper
I think I recal the conversation and understand that it may not be possible at the moment.
If I can help further in the future please let me know.
30th January 2009, 12:33 PM #12
We have an IBM only school district so we use their built in client Acess Connections. I HATE IT! There are so many problems with it...but that is another story. When it actually works I can tell you basically anything about APs in or close to the area of the laptop on. There are other open source tools (the names are escaping me at the moment) that work in a similar fashion. I seriously would consider testing some of these out because if it is just a matter of reconfiguring the APs because they aren't working right that could save you alot of money and/or time if you can pinpoint it to that. Trust me I know what you are going through we have a huge district with about 30 of the trolley's and over 60 APs. Wireless is always an issue.....
30th January 2009, 04:28 PM #13
I have wandered around the school many times using netstumbler, i know the channels are all conflicting with each other. I wish i could just turn them all off. but i would just end up with student after student coming asking "why isn't the domain available"
30th January 2009, 04:42 PM #14
Tom, have you made sure that the APs are only operating on channels 1, 6 & 11 (13?). It is important that you use these, and only these, since chosing others will cause greater interferance. It is better to have APs that operate on the same channels, since the can then 'see' each other, and allow for each others traffic better. Using the middle channels will only slow things donw even more. All of the managed WiFi systems I've used use only these 3 channels.
30th January 2009, 04:55 PM #15
Tom the above is a very true and vital for good wireless.
Originally Posted by tonyd
13 will work but will overlap with 11 quite a bit in standard omni directional antennas due to how close it is.
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