Charterhouse School in Surrey is one of the UK’s oldest educational establishments and its construction bears the hallmarks of that age in the shape of one metre-thick stone walls. When you are contemplating installing a Wi-Fi system that thickness presents something of a challenge to radio waves, while the heritage angle makes adorning the older listed buildings with radio equipment problematic, if not impossible.
The school did have a legacy Wi-Fi provision in the form of an off-the-shelf system of home access points dotted around the campus providing pockets of wireless. Clearly, this was not going to be adequate in the age of the smartphone and tablet.
Iain Wilson, network manager at Charterhouse School, says: ‘We took a step back and looked at the whole campus to see how we could best utilise wireless. What we did have already was a lot of fibre optics and a core switching server infrastructure, which we’d installed the year before.’
The task now was to provide wireless connectivity to as much of the campus as possible with the right amount of capacity to meet user demand. The school put the project out to tender and assessed the bids.
‘We weighed them up in terms of benefits specific to education – both student and staff needs. Those are two different experiences requiring different types of access to different resources,’ says Wilson.
The wireless bidders put forward a variety of solutions, which they presented to the school. ‘We looked at solutions involving controller versus non-controller environments and return on investment costs,’ says Wilson. ‘We all thought the controller-less solution was appealing in small or less complicated environments, but if you want to scale up you really need a controller, so that narrowed it down. Then we looked at the cost benefit and how the proposed solutions fitted with what we had already.’
HP Networks emerged as the chosen provider. Not only was its price very attractive, along with meeting the technical specifications, but the integration of its solution with the school’s existing communications infrastructure was seamless.
Lars Kølendorf, wireless solutions manager EMEA, HP Networking, says: ‘In terms of controller versus controller-less architecture, I was happy that when the school looked into the financials it saw the benefit of the controller solution and the ability it provides to scale up the network as well. If you need more access points then the controller recognises them, you just plug them in and it adopts them. There are a lot of benefits to be had from controller-based architectures. When you look at capital purchases and capital expenditure against revenue expenditure, there is quite a noticeable difference as you scale up from a few APs to 50-60 APs.’
Once HP’s solution had been chosen, one of the first aspects that had to be overcome was providing the right wireless experience for staff and pupils. The school staff are issued with equipment, such as laptops, for which they expect a certain throughput speed.
‘But we cannot control the student devices,’ says Wilson. ‘They have anything from old mobiles to top of the range new laptops and tablets. But we did not want anyone to suffer any degradation of service, so if staff are using 300Mbps laptops and student comes in with something more powerful, we don’t want to reduce staff throughput to 11Mbps.’
In terms of handling numbers of concurrent users, Wilson says there are usually 20-25 students in a class, so the network has to support that number, but there may also be 30 delegates in a room outside of a class perhaps using the school’s in-house video system to stream video. So the requirement was that the wireless system has to support a minimum of 30 people per access point (AP).
‘One reason we stuck with HP was that we are very au fait with its ProCo software manager,’ says Wilson. ‘ProCo manages switching infrastructure, port utilisation, user format and configuration, the state of the switches and so on. It gives us a single pane, whereby we can quickly identify AP malfunctions, look at statistics and check the users. We can see heat maps and observe what parts of the network get high usage. It also means we do not need to integrate with another vendor’s equipment. Instead, it is all integrated.’
The equipment supplied by HP comprises two 460 HP MS wireless controllers, two 760 access controllers, 53 HP MSM 466 access points, and four HP 2520Gb POE (power over Ethernet) switches.
In terms of connectivity, wireless microwave connections were not an option as the school cannot put radio equipment on its listed buildings. Two years previously, Charterhouse changed its end and core switching and installed a 10GB site-to-site link with redundancy built in with the deployment of two fibre optic cables with link aggregation.
‘One of the key benefits of our architecture is that it can be optimised,’ says Wilson. ‘We can choose centralised traffic or localised traffic and we have the ability to do both with the same AP and same controller at the same time. It means you get very secure traffic and can provide video streaming or e-learning by distributing the control within the network.’
The school uses InMon’s sFlow standard to monitor its network. The product provides complete visibility into network equipment and enables effective management and control of network resources. ‘It gives you the ability to log and monitor everything on the monitor, be it wired or wireless,’ says Wilson. ‘It is built into HP’s 466 APs, so no matter whether it is centralised or distributed, how much bandwidth is being used, what the hotpoints are and so on, it is all open source, so it is visible in all applications.’
Kølendorf says: ‘The difference is that you do not lose that ability to see what is happening on the network when you do local switching. The dilemma is that if you use a controller-based wireless network, you do not want to lose that visibility when you switch to local control. With our 466 APs you don’t lose visibility when you switch to the local controller – hence the network optimisation.’
Wilson cites an example of the advantages of such visibility: ‘It helped us spot two viruses on laptops very quickly and we could identify the matching spamming in a matter of hours.’
The school has four wireless air Virtual Local Area Networks (VLANs). ‘One is a total guest network, which is deemed appropriate when we do summer lets,’ says Wilson. ‘It has no authentication and no security, but it does go through our APs.’
Of the other three VLANs, two are for members of staff: one is for their own devices, which have to be approved; the other is for school netbooks. The aim here is to simulate being on an Ethernet work environment. It is encrypted, but appears as a standard nettop matching system.
The final VLAN is for students. There is no key required to join and it is device agnostic. Once logged on the students are limited in what they can access. ‘We’ve opened it as much as we can, but with limited scope. They can browse the school intranet, however,’ says Wilson.
He adds that hotspots in the boarding houses is the end game, but there is a strong feeling that pupils should not have Wi-Fi access in their bedrooms, as that might distract them from studying. Kølendorf says that a wireless survey was undertaken to assess the right locations for deployment of Wi-Fi across the rest of the school. ‘We have done all of the teaching buildings, where we have installed one AP per classroom for resilience and throughput. The final phase will comprise directional antenna APs to cover sports grounds, the café and other outdoor areas, otherwise it’s all indoors at the moment.’
How have the staff and students taken to the new system? ‘When it first went in it was adopted very quickly,’ says Wilson, who reports that the network has not been maxed out and is coping with demand as the network scales up across the rest of the campus.
Will faster and higher throughputs be required in the future? Kølendorf says that HP will soon have 1GB internet connections. ‘We now have 900MB APs on the controller and we need to cope with the 802.11ad Wi-Fi standard, which is coming and that means 2.6GB throughput per access point. The benefit is that you just plug in those APs where you need them into the same architecture. 802.11.ac will be the new standard in a few years [802.11n is the current standard). But our controller just adopts it. It is not a bottleneck, you just add another AP if you need it.
‘We actually used the same AP mounting brackets,’ he continues. ‘The 466 APs come with a bracket that fits the old mounting, so you just twist out the old one, pull out the cable and put in the new AP.’
Kølendorf adds: ‘I would like to say that for keeping the price down you can use the same number of APs from 11MB up to 50MB. It covers a larger area, but it is handling the same amount of users. If you can reuse the same AP sites that not only reduces the cost, but you also get a much higher performance. The cabling and mounting is the expensive bit.’
The HP system has now been running for six months. Wilson says: ‘It has been very successful and other schools are looking at us as a benchmark, which is praise for HP.’