Networking for 1 to 1

 

With future posts I will look at pedagogy but this post will consider networking and it’s implications. The reason being that often people don’t understand the implications of adding more devices onto their networks, where the bottlenecks are etc. I hope that this post will make some of it easier to understand and help those making decisions for 2010. Otherwise we may hear this type of talk…

“We have got a whole lot of netbooks and all of  sudden the network seems awfully slow.”
”We used to have good internet and now students are waiting a long time for simple things to happen.”

There are large implications to increasing client density on our school networks (these are not just about our internet connection but internal also). 
What do we need to understand, do to create and maintain a network suitable for 1:1 student use?

5 Big ideas

• The Network is now the most important part of Schools learning technologies infrastructure
• Network contains 4 main components – Internet connection – Backbone – Network Layering (segmentation) – Wireless Access
• These components have to match with client (device) density if the users experience is to be a good/successful/meaningful one
• Wireless access is the only suitable way to deliver ubiquitous/natural learning technologies
• "the value of a telecommunications network is proportional to the square of the number of connected users of the system" Metcalfe's law ie the more people connected the more learning the more opportunities.

A closer look at these

The Network is the most important part of the Schools learning infrastructure

It used to be that schools spent their money preparing servers to host mail, files and programmes. Now much of this functionality is moving to places outside the school. Schools are pooling forces to consolidate these like Nayland College who share a server with Nelson Girls. Network connectivity is the key to this. For a school to host the increasing number of devices that are being plugged in; or to enjoy wireless networking attention to this is important. In our school over 250 more devices are connected this year than last. Next Year and additional 230 are predicted. It could be  a bit like trying to fit a cities traffic down a normal road if we don’t take a few crucial steps.

 

The Four Main Components

Internet
As shown above High speed internet to maintain service levels if we connect more devices to our network. Jetstream is not able to put information from our schools onto the internet nearly as fast as it can bring it down so when more of us want to use web 2.0 tools we will struggle to do so.

Backbone
The connections between buildings and switches (think old telephone exchanges) is our backbone. Fibre optic cables and fast switching are needed if we want to avoid bottle necks and teacher frustration.

Network Layering
When a computer or other device on a network wants to talk to another one it can happen in number of ways. In most school networks traditionally the device would ask all of the others if they were the right one ie send its message everywhere in a hit and hope type exercise. This was not such a problem when there were a small number of devices involved but now there are hundreds it can make things noisy and slow. To speed things up we can segment a network (make it layer 3) and send the traffic directly to where it needs to go. The important message here is to use layer three capable switches in our networks.

Wireless Access
The most difficult to get right but the most important in many ways because this is the where connections to the network for 1:1 devices will start. Schools need enterprise level wireless to manage 1 to 1 devices. A good system will be characterised by a central wireless management unit. What this does is ensure that access points are not competing with each other and that clients are handed on seamlessly from one to another.

The match to Client density
More devices = more bandwidth required for the same experience. Work using local software if the network can’t support multiple online users.

The value of 1:1 has come from the value of the network ie the value of connectivity.
We need to get our network environment right for the value of connectivity to show through. My next post will be a reflection on the realities of pedagogical (teacher readiness) for 1:1

For a look at the ideal world of a 1:1 implementation read this on Wesley Fryer’s Blog and then read the comments which allude to a hardware environment being funded but teacher readiness not. To get teachers ready is a more complex process than getting the students and their devices connected. In my mind we jump across and action research our way to individual teaching success. See easy isn’t it?

Reason 1 Why we are moving to the cloud?

Who Wants to manage servers?

What's the purpose of managing these?

If they can't be accessed in anywhere anytime are they still of value?

The bubble share shows one medium sized schools infrastructure and we have invested many hours keeping this going.

Educational fibre loops and external providers should reduce this need.

We have moved 1 server from the rack which is the big hole at the bottom.

How do we escape? Step 1 google docs

BubbleShare: Share photos - Play some Online Games.

Shozu mobile uploader

I have been using Shozu with my n95. It think it is pretty good sofar. Following is a movie of how to and a sample I have recorded with Divneet.

Just shows why so many people are marking mobile use a key tech trend.

The new decisions

The purpose of this post is to look at the reasons I see for the new and increasing importance for schools to have robust, open and protected wireless networks. It is also to compare two products (Ruckus and Bluesocket) looking to provide solutions in this area as a cognitive reflection on our own decision making in this area.

Why wireless development.
With most schools having robust network backbone in place we want to escape wires to create a more natural connection allowing us to be more flexible in where we are able to support the diverging devices that are able to connect wirelessly.
Wireless access is of course not new but as we scale the clients in a network the throughput of our wireless system has to develop to provide acceptable service to each client device. Netbooks and mobile devices are bringing the feasibility of 1 to 1 for more and more schools, and indeed home environments. The use of wireless gateway devices allow us to control wireless traffic and present easy access to the internet for guests and a wide variety of devices eg psp, phones etc.
What we are doing at our school
In our school we are introducing 200 new wireless device to one building within the school and will extend this to include another 125-150 in 2010.

Making a choice
This is not an insurmountable problem as there are some clever options available vendors using the 5Ghz spectrum can have more radio channels overlapping and therefore greater Access point density. Most of the solutions also provide for self managing access points. By this I mean once a controller is established additional access points are able to find it and set themselves up. We have looked at four solutions to this wireless problem. The vendors being Bluesocket, Ruckus, Xirrus and Trapeze.

Ruckus

Advantages Ruckus Equipment.

• The controller will not become a bottleneck for traffic as it is responsible for authentication, management rather than a router of traffic.
• This requirement makes Bluesocket more expensive long term as client density will outgrow controller throughput.
• The wireless access points work well in a noisy environment directing traffic to the clients that need it
• The 802.11n APs are priced at a point that means we can move to this standard now rather than redeploy within two years.
• We have also experienced the Ruckus Solution working at learning conferences here in New Zealand where many clients were able to connect and hold reasonable wireless service.
• The Ruckus APS can work as mesh in other words find each other and extend their range without wires.

Disadvantages

• Offers only 2.4 ghz radios which have only 3 channels available and may suffer if placed to close to each other.
• Even though they operate in the 802.11n the n clients will not benefit until they are the only ones present as the access point will drop to meet the needs of the weakest client eg operate in 802.11b if a b client is present.
• While the ruckus traffic is not directed through a router this means it will all take place on layer 2 of the network meaning that having a high density of clients is likely to degrade network performance for everyone.

We are still considering the verdict and at the moment we see ruckus as a terrific solution to medium density sites where meshing may be of benefit. In a higher density 1 to 1 environment we are starting to think it may struggle.

Will discuss other options in next post.