The Building Blocks of ICT Networks
This section of my article on technology is really aimed at leaders who have limited understanding of how networks function. As a head teacher you will have some pretty big cheques to sign off and knowing what exactly some of the hardware is might make it seem less daunting. I’ll start with the end you will know as a user. The interface or the thing you use to do whatever it is you are doing with technology.
You use computer interfaces everyday, your digital watch and its buttons, your programmable microwave, your alarm clock, the cashpoint and so on.
The past decade has seen a significant shift from large desk based devices to mobile devices that can go anywhere. Young people are nearly all fully engaged with mobile technology and even pupils from disadvantaged backgrounds seem to ensure they have adequate technology (probably foregoing other perceivably more essential items). Yet schools continue to ban personal devices, instead battling with pupils over paper planners and missed homework that might conceivably be better integrated into the digital solutions they all have and want to use.
Over the next decade I suspect that schools will see a shift away from traditional desktop devices to more mobile devices or cheaper desk bound alternatives such as dumb terminals. Dumb terminals are basically a monitor and keyboard connected to a server somewhere else in the building (a big computer). Schools need to evaluate their current policies on banning (or allowing) mobile technologies and consider how they might be used effectively and safely in the future.
With dwindling school budgets, there is also a strong argument that implementing a ‘bring your own device’ (BYOD) system may result in savings for schools although with such a policy, great care would need to be taken to ensure safe use of such devices.
The bottom line is that I am convinced there will be a shift away from bulky and expensive desktop machines. However, there are pros and cons when considering what interfaces to buy. Some things to consider:
- Laptops and mobile devices have the obvious benefit of being mobile (assuming good wireless connectivity) but in my experience are not as viable when used by pupil populations that are prone to vandalising or abusing equipment. It is worth noting that a new desktop keyboard and mouse can be had for less than £5 but a new laptop keyboard will likely cost in the region of £30-80 (or more) and take a considerable amount of effort to replace compared to a desktop keyboard and mouse. Tablets generally tend to be very strong save only for damage to screens which effectively write off the device due to the cost of replacement. If you are purchasing mobile devices you need to think about where the devices will be stored, who will supervise their use, whether it is realistic to assume that deliberate damage can be minimised or stopped and the impact it will have on learning if five machines have been damaged and are out of action for a fortnight. PERSONAL VIEW – laptops are best used where a limited number of staff will have responsibility for them, their use will be carefully monitored or where pupils have a high level of maturity and look after school equipment.
- Dumb Terminals – are basically a keyboard mouse and screen. The complex workings that you would expect to be taking place inside a traditional laptop or desktop machine take place on a large computer called a server which actually does the job of many computers all at once. If you choose this route the interface is a relatively cheap affair, with screens, keyboard and mice being cheap but your school will need a robust network of cables to handle the data being transferred across the network and the servers are more expensive. You will find that dumb terminals lack the mobility of laptops but take up less desk space and pupils can use desks for writing or computer work. PERSONAL VIEW – dumb terminals are good if you have a network capable of supporting this technology but don’t expect them to do processor heavy stuff like video editing, picture editing or CAD/CAM work. You are better off using desktop machines.
- Desktop machines. Everyone will be familiar with the desktop computer. Like the computer you have at home save for the fact that you logon across a network and your work is not saved on the local machine and is saved elsewhere in school on a fileserver or SAN, the desktop machine is a robust device; damaged screens, keyboards and mice are easy to replace and not too expensive but they do take up space and it can be difficult for pupils to swap between computer work and writing. They are also generally cheaper to install than laptops but require dedicated computer rooms. They are also more effective for processor heavy activities such as CAD/CAM, photo editing or video production. PERSONAL VIEW –the best choice for processor heavy stuff like video editing, picture editing or CAD/CAM work or where you have problems with pupils damaging equipment.
- BYOD/personal devices – bring your own device or personal devices. Some schools allow pupils to bring their own devices or provide personal devices. Whilst this can make a huge saving on school budgets (when pupils are expected to bring their own devices) there are a myriad of problems associated with ensuring devices are all able to access school networks, how pupils are supported with such a variety of devices, how to support the training of your ICT team to cater for such diversity and also how to ensure safe access and use. PERSONAL VIEW – BYOD/Personal devices would work best where pupils use the same technology. Perhaps when schools have purchased specific items or subsidised the procurement of personal devices. Pupils having ownership of devices means they are more likely to value them and look after them but you will need robust policies and procedures for safeguarding. Processor heavy activities will still require dedicated machines for this although the use of remote servers (e.g. using your personal device to access resources over the internet) is also a possibility.
What sits behind your user experience
Most head teachers will know that there sits behind the user interface lots more expensive technology. So what exactly is it all, what does it do and why is so expensive? For most users the point of interaction is their only knowledge of the school’s ICT infrastructure save for a few people who might have caught the odd glimpse of the school’s network room with its icy cold air and banks of beeping and flashing machines.
Underpinning the users experience there needs to be a robust network infrastructure. You need to have in place a backbone of good quality network cabling and fibre optic links to ensure data can pass quickly around the site. In most schools services are provided to users by way of machines known as servers. These are machines much like your desktop machines although they generally do one job only, albeit for many users at once, where as your personal desktop machine at home has to do all jobs for one user only.
As a minimum most networks will have a domain controller (something which allocates logons to users), an application server (which allows software to run) and a SAN or storage area network (allowing users to save work or files). If people need access to the internet there will be a web server and email is controlled by a mail server. Print servers sort the printing, MIS servers (management information systems) contain all your staff/pupil data, CCTV servers control your cameras, media servers store media files such as video and remote servers allow external users to access systems at school when they are geographically separated.
Each server or machine is a physical device which needs to be bought, installed, maintained, cooled, powered, often licenced, insured and takes up space. Network rooms therefore fill up quickly and are expensive. Since the machines have to be powerful and work with multiple users they are expensive and can cost anything from a 2k up to 10k plus.
Traditional Network Architecture:
Historically, most schools have adopted a traditional setup with one server doing one job. If a server breaks down that service is lost until it is repaired meaning loss of business continuity to users. It might be no big deal but if it is the same time as OFSTED have announced they are coming in and you can’t email documents over in advance, or the police have turned up with a worrying safeguarding concern about a pupil and your management information server has failed, both could have dire consequences.
I might start building my network purchasing servers like this. Each one is a separate cost and is added on to my network. You can see quite quickly my server room is going to get filled up, I will need a significant amount of cooling, power consumption and so on. E.g.
- Server 1 – Print server
- Server 2 – Mail server
- Server 3 – Application Server
- Server 4 – Web Server and so on
Virtual Network Architecture
In the future schools will need to give serious consideration to virtualisation of servers and workstations. This involves buying high specification servers in the first place and creating multiple virtual servers within. This can reduce the number of physical machines needed with savings in power consumption, cooling etc… Each server machine basically does the job of the many servers you might buy separately in a traditional network.
Setting up two virtual servers that work together means greater speeds can be achieved and when one fails, the functioning server will automatically take over all responsibility and in some cases can even do this by actioning a predicted failure. Users are left unaware of what has happened and continue to use the system as normal.
- Server 1 – (comprising 4 virtual servers and mirroring Server 2)
- Server 2 – (comprising 4 virtual servers and mirroring Server 1)
0% downtime to users is therefore achievable. When such virtual servers are separated geographically (e.g. in different buildings) not even the loss of a building can stop your network functioning.
There are clear advantages to virtualisation:
- Less hardware means less cooling and less energy consumption.
- Unsupported legacy software can be set up on a virtual server.
- When new software is installed it can be tested on a virtual server first to make sure there are no compatibility issues. Such advantages again limit any loss of service to users.
- Less manpower needed.
- Business continuity.
- Less hardware to purchase and less equipment to replace.
- Less physical space needed.
Storage of Data
With traditional network architecture data has been stored on site on fileservers or SAN (storage area networks). Schools do not need to use localised storage anymore as there are now big companies offering cloud storage; which effectively means your data is simply stored on one of their computers, perhaps not even in this country. Such big companies are also capable of providing back up services that far exceed any capacity a local school might realistically implement and the security measures are also incomparable. Movement to cloud storage also results in reduced hardware and energy costs and near infinite storage capacity.
With the cost of software being unattainable for some pupils to own personally, the use of remote servers can break down barriers to access for disadvantaged pupils and schools might consider funding infrastructure using pupil premium funding. Remote servers basically allow pupils (and staff) to access software in school by effectively logging on to a virtual computer over the internet. Pupils don’t need expensive computers to run processor heavy software since the software runs or expensive school servers. The remote server simply provides a connection and the users own device simply needs to be capable of rudimentary web browsing.
Part 3 to follow –areas of technology to watch in education.