Gigabit Wireless AP

[max12590]

I am the IT intern at my school and I am working on finding a solution to a problem we are having in a classroom. We have a biology class equipped with around 10-15 Lenovo laptops. The teacher wants to use these for a program called CyberEd. It is an extremely multimedia intensive application. The laptops are currently networked using an Apple AirPort (b/g with 10/100 ports). This is not able to provide the throughput to stream the CyberEd application to 10-15 computers simultaneously. We have come to 2 possible solutions; hardwiring (we know that the network can stream the app over a 100 Mbps link, we've done it in other classrooms, and a better wireless solution.

At this point it is worth noting that the installation of wiring is somewhat cost prohibitive (don't ask why, the situation is moderately complicated, but it is not feasible, at least not at this time). With that in mind I threw out the idea of a gigabit WAP. Getting a gigabit line to the room would not be hard at all. I feel this may work, as I doubt the 54 Mbps connection is the bottleneck, more likely the 100 Mbps.

So now I want your thoughts. Is this the best option? Apple makes a gigabit AirPort and Linksys makes a gigabit AP (WAP4400n). These are relatively inexpensive. Do you think multiple 10/100 APs in a pseudo-mesh configuration would be better?

Also, the school does have one of the gigabit AirPorts in service elsewhere. Tomorrow I will probably connect this to a gigabit port, fire up 15 macbooks and see if they can stream high-res video simultaneously. I'll let you know how this goes.

Thanks, Max

 

[Impotence]

I think the reason you are having a problem is that sharing 54MBits (theoretical speed, most of the time it does not reach this especially if use enable WEP/WPA) of bandwidth between 15 laptops is a major bottle neck for anything.

Thats only 3.6MBits of bandwidth per machine (a WAP is like a hub, not a switch).

Even a wireless-N router would only give 20MBits of bandwidth per machine (for 15 laptops) at its maximum theoretical speed.

Wires are always going to be faster, cheaper and are much less of a security risk. (as you probably know, WEP is useless... and i doubt WPA will stand up forever).

Why not run a Gigabit connection to that room and put a Gigabit switch on it and wire all the pc's into that? (that has to be cheaper than buying a Wireless-N card for ever machine?)

 

[max12590]

As I said, wiring is cost prohibitive. Believe me. If it was feasible that is what we would be doing.

Anyways, so what you're saying is that each computer does not get 54 Mbps. If this is the case then a gigabit ethernet connection would not matter. Is this correct?

 

[donkey42]

i agree wired is much more secure & has a much more sustained throughput than wireless, however, if you or your tutor insist on using wireless, you'd have a much greater chance of it working if you used a Linksys WRT54GL as it is the best wireless provider, if it still won't work consider throwing a new firmware at it, DLed from http://www.Sveasoft.com or http://www.dd-wrt.com/ failing that your only alternative is wired

BTW: personally i've never used wireless, but, i may add a WAP at some time in the future

Edit:

Anyways, so what you're saying is that each computer does not get 54 Mbps. If this is the case then a gigabit ethernet connection would not matter. Is this correct?

• wireless - yes
• wired - no

 

[max12590]

Well, the WRT54GL is definitely not the best option here. First of all, a router is not needed, and to support these clients a more powerful AP would be needed. I talked to my boss today (separate from my school's IT guy, my boss is the sysadmin for a tech firm) and he suggested a combo of gigabit and MIMO. This would give more throughput on the wireless side and the ethernet side. I am thinking the Linksys WAP4400N would serve the purpose pretty well. The other thing that if one AP isn't enough it isn't much to throw another one in configured on a different channel and SSID.

Also, security is of extremely little concern here. First of all, the AP(s) will be located on the third floor of the school, and about 100 yards from the closest road. And, to crack even WEP encryption a student would have to bring their own laptop and sniff the packets. Furthermore, even if someone did crack it, it wouldn't matter, they would be getting to the exact same place as if they hopped on any of the few hundred other computers in the school, just wireless.

 

[Impotence]

the Linksys WAP4400N is a Wireless-N router, you will have to buy a wireless-N pcmcia or mini-pci card for EVERY laptop (and there not cheap).

IEEE 802.11n is a proposed amendment to the IEEE 802.11-2007 wireless networking standard

802.11n is not standardized as far as i know, you have no guarantee that anything you buy now will work with routers/clients that follow the official specification (when its released).

as far as i know, even with MIMO the maximum theoretical speed with 802.11N 300MBit/s and that it still shared between the clients. How much bandwidth does this multimedia app use? have you measured it?

Also, security is of extremely little concern here. First of all, the AP(s) will be located on the third floor of the school, and about 100 yards from the closest road. And, to crack even WEP encryption a student would have to bring their own laptop and sniff the packets. Furthermore, even if someone did crack it, it wouldn't matter, they would be getting to the exact same place as if they hopped on any of the few hundred other computers in the school, just wireless.

...Or sit just about anywhere they want want a directional antenna or yaggi (outside the boundaries of the school). My personal best (against my own router) was 1 minute and 42 seconds from the other side of the road that my house is on (inside another house, weak signal).

Whoever it was could use one of your laptops, all they need to do is boot from a liveCD or USB stick (or even a SD memory card in a camera), disabling booting from cd / usb in the bios is not much help, neither is password protecting those options and it only takes a few seconds to take tha back of the laptop off and clear the CMOS (and you wouldn't know who it was that did it, as they would be long gone by the time you found out!).

If someone is on your network with malicious intent not only will they be able to see any traffic they want (even through switches using forged arp requests / replies) but they will also be able to manipulate traffic (or even embed browser exploits into HTTP traffic moving across the network).

WPA-PSK is many many times better than WEP, as long as you use a strong complicated paraphrase...

 

[donkey42]

well i did say

BTW: personally i've never used wireless, but, i may add a WAP at some time in the future

and the info i posted was what i'd found on the net, i will have to be more careful in the future, to only post what i know about, and, not just what i've researched, although, it did work

Edit: thank you for teaching me a valuable lesson Max

 

[max12590]

the Linksys WAP4400N is a Wireless-N router, you will have to buy a wireless-N pcmcia or mini-pci card for EVERY laptop (and there not cheap).

Yes, the WAP4400N is Draft 802.11n certified. This does not however, in any small way, mean that it won't work with wireless b/g devices.

From the Linksys product page:

Complies with IEEE draft 802.11n standards while at the same time being backwards compatible with 802.11b and g devices

All that being N means to me is that it should function as an 802.11g MIMO AP.

And, back to security. Yes, someone could crack a WEP key easily. That however, does not give them any more power than if they were to simply sit down at a hard wired machine, which they can gain access to by walking into the library and using the username and password they already have (well, yes, they could look at the wireless traffic but why would you eavesdrop on someone looking up wikipedia articles on biology?).

So yea, I still have the question, will a wireless-N router with gigabit ethernet give me the bandwidth to support 10 laptops streaming multimedia?

 

[Impotence]

Yes, the WAP4400N is Draft 802.11n certified. This does not however, in any small way, mean that it won't work with wireless b/g devices.

I don't think you would get any advantages of 802.11n if the clients only have 802.11b/g wireless cards, MIMO is not part of the b/g spec (and it requires multiple transmitters / receivers in the NIC)

So yea, I still have the question, will a wireless-N router with gigabit ethernet give me the bandwidth to support 10 laptops streaming multimedia?

You need to find out the peak bandwidth usage for this program, streaming multimedia could use anywhere between KB/s and MB/s depending on its resolution, codec etc.

We cant even start guessing without it!