Web hosting. Web hosting

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1 Web hosting Web hosting Becta 2004 Valid at September 2004 page 1 of 7

2 Web hosting Contents 1 Introduction What is web hosting? What different hosting options are available? Virtual hosting Dedicated hosting Do it yourself What are the requirements for hosting a site? Technical expertise Internet connection What do I need to be aware of when hosting a website? Secure transactions Interactivity Dealing with suppliers Remote administration Frequently asked questions What connection speed will I need? How does web hosting influence network security? Will I require a static IP address? Should I have a disaster-recovery procedure in place? How do I get a.sch.uk,.gov.uk or.ac.uk domain name? What are the costs of web hosting? Summary Supporting material Useful links and resources... 7 Becta 2004 Valid at September 2004 page 2 of 7

3 1 Introduction The purpose of this technical paper is to give an overview of web hosting and how to use it in education. The paper will introduce what web hosting is, outline the different hosting options available and answer some frequently asked questions. The paper aims to highlight some of the key issues to consider before embarking on a web-hosting project. 2 What is web hosting? The term 'hosting' refers to the storage, retrieval and technical maintenance of web pages, whether public or private. 'Web hosting' is hosting in the public domain, making content available to all internet users. At its most basic, a host is an always-on computer with two-way links to other computers on the internet, and a server is a computer with software that supplies services to another computer. Any arrangement for web hosting must therefore comprise a host computer and a server, where the server stores the web pages in a form that can be accessed and read through the host. Usually the host and the server are the same machine. Web pages are the information sources on the World Wide Web. It is easy to create web pages using hypertext mark-up language (HTML), and this allows you quickly to publish information to a global audience. Web pages can form a private document or be part of an intranet or public website, depending on the access allowed to the host computer. 3 What different hosting options are available? There are three different arrangements for hosting a website, each with different levels of flexibility, complexity and cost. 3.1 Virtual hosting Virtual hosting typically includes domain name, addresses and website file storage. You manage a website by using either the virtual host's web-based management and creation interface or by using FTP (file transfer protocol) software. Virtual hosting is located at the internet service provider (ISP) or third-party supplier, with hosting space shared on one computer by a number of website operators. Each website operator can control the file structure of their own website, but they cannot affect the operation of the server or install new software. Virtual servers are a cost-effective means of providing a basic internet presence, but they tend to be inflexible and can restrict the level of interactivity of your website. Virtual servers are not suitable for sites that are likely to generate considerable traffic or place a heavy burden on the server. Some hosts limit the number of downloads per month. 3.2 Dedicated hosting A dedicated hosted website has its own server, which it does not have to share with any other websites. Administering the site remotely, the website manager is responsible for the website files, the host operating system and server software. The server belongs to an ISP or a third party and both maintenance of the internet connection and disaster-recovery procedures are their responsibility. To simplify administration, domain-name hosting, and FTP services often come with the package. Dedicated hosts are suitable for sites that are likely to generate heavy traffic and often provide better internet connections than those commonly available in-house. By allowing the website Becta 2004 Valid at September 2004 page 3 of 7

4 manager to change the configuration of the server, they also offer more flexibility than virtual hosting. Dedicated hosting requires a certain amount of technical expertise. 3.3 Do it yourself If you have a permanent internet connection and a suitable computer, you can set up a web server on your local network. Your host computer must have a permanent IP (internet protocol) address. An IP address consists of a series of numbers describing the location of that computer on the internet. If you have an internet server on a local network, it needs a permanent IP address that other computers on the internet can see. The provider of the internet connection generally assigns IP addresses. The do-it-yourself approach allows more flexibility and control over the hosting process and you can administer it via FTP or through the local network. For this approach you will need to consider the implications of providing your own hardware, software and technical expertise. 4 What are the requirements for hosting a site? When setting up a web server, you need to take into account a number of basic considerations. These often form part of an organisation's networking policy and an arrangement with an internet service provider will include them as standard. 4.1 Technical expertise Internet servers require both software and hardware maintenance. Software installation can often prove complex, with unstable computer applications and security problems an issue. The operating system, hardware, web server and any associated software such as a database need the appropriate level of support. Specialist knowledge such as programming and system administration may be necessary. These skills often form part of an ISP's service, though to reduce its own technical burden the ISP may limit the choice of software. If you choose to host your own website, the choice of software and operating system will be affected by factors such as the ease with which you can acquire the appropriate skills, the costs involved and the systems you already have. A technician who can administer a Windows NT server may need considerable further training to administer a UNIX or Linux server, so access to technical expertise either locally or from a service provider directly determines the choices available. Remember to include the cost of training in any cost comparisons. 4.2 Internet connection Three major factors affect the performance of a website: its popularity the more visitors to a site, the greater the effect on performance the reliability and speed of its internet connection the quality of the host computer and software. The design of the network and the speed of the connection to the internet determine the quality of the internet connection. 5 What do I need to be aware of when hosting a website? What is involved in hosting a website depends on your requirements. Different operating requirements often need specific software or operating arrangements to facilitate them. If you want to offer secure transactions or interactive content, this may influence your choice of host, as will your choice of operating system, content-management system, scripting language and publishing model. Becta 2004 Valid at September 2004 page 4 of 7

5 5.1 Secure transactions If you intend to provide services or business functions over the internet, security is important. Where financial or personal information is involved, the hosting arrangement should include secure server software, which often includes proprietary certification by a third party such as Verisign. A secure server transports data using SSL (secure socket layers) or TLS (transport layer security), which both encrypt data travelling to and from the server. If you do not use a secure server, website users may be reluctant to give personal information. The implication for web hosting is that any server software must support either SSL or TLS if it is to allow secure transactions. 5.2 Interactivity Dynamic content and server-side interaction require the use of either scripting or programming languages. Many scripting and programming languages have specific platform requirements. Server-side programs (which require actions to be carried out on the server before delivering the file or web page) written on one system do not automatically work on another. For example, in order to run Java Server Pages (which produces pages ending in.jsp) you must have a Java server installed on your host computer. What are the implications of contracting out hosting? 6.1 Dealing with suppliers A considerable administrative burden is attached to contracting out any service. In web hosting, you need to deal quickly with changes in server configuration and problems with connection and service quality. The quality of technical support is therefore very important and should be available 24 hours a day, 365 days a year to ensure that 'mission-critical' problems are quickly solved. As it is very expensive to provide adequate technical support, some companies outsource their provision. 6.2 Remote administration If an ISP is hosting your website, there is an added level of complexity in administering your system. If you host your server locally, you can sit at the server to make any changes. If you use a remote host, you will need some form of connection and administration tool. Some companies offer only FTP, while the more complex solutions may allow you to telnet and take complete control of the server. Major changes to configuration can be difficult to implement with remote administration, because of the need to access the server's operating system. 6 Frequently asked questions 7.1 What connection speed will I need? You can arrive at the amount of bandwidth (connection speed) you need by multiplying the combined size of all your web pages by the number of times you expect people to download them. We measure bandwidth in bits per second (bps). One bit is one eighth of a byte. For example, for a single 34-kilobyte (KB) web page (with 4KB HTML and three 10KB images) to be downloaded 50,000 times in one month, we would require 13.6 Megabits (Mb) of bandwidth per month. The calculation is 34KB x 8 = 272Kbps x 50,000 = 13.6 Megabits per second (Mbps). Assuming that most downloads are during certain peak times such as 9.00am pm Monday to Friday, which comes to about 160 hours a month, you will need a bandwidth of 85KB per hour, or 23bps for a single page. Becta 2004 Valid at September 2004 page 5 of 7

6 A site of 10 pages of similar size and popularity would require a connection of at least 23Kbps dedicated to serving web pages. It is important to realise that this is a very rough estimate, and that, in practice, bandwidth is difficult to predict with certainty. If other applications such as and internet access share the internet connection, it needs to be faster still. As few internet connections ever achieve their maximum connection speed, you need to allow extra bandwidth. In reality, therefore, for our example above we would probably want a 150Kbps connection. 7.2 How does web hosting influence network security? If your internet server sits inside your organisation's local area network, the network architecture (the physical design of the network) may cause problems. For security reasons, network administrators may well try to prevent external access to computers within the organisation. Depending on policy, you may need to locate your internet server outside your network's firewall. If this is the case, your organisation may have already placed other internet servers in a special network outside the normal firewall; otherwise, a separate internet connection to your internet server may be required. 7.3 Will I require a static IP address? Internet servers require static IP addresses that are viewable on the World Wide Web. As numbers of IP addresses are limited, some organisations assign them dynamically, with a different address allocated every time. Some organisations also use proxy servers, which mask the IP addresses of local machines. Neither of these options is suitable for an internet server. 7.4 Should I have a disaster-recovery procedure in place? Disaster-recovery procedures need to be in place to ensure that, in the event of a disaster, your organisation suffers little or no disruption. Internet service providers should have disaster-recovery procedures in place as part of their service agreements. If it is critical for your website to be always available, it may be a good idea to mirror the website at another location. If the main host fails or becomes overburdened, requests are seamlessly diverted to the second host and no interruption of service occurs. It is, of course, vital to back up regularly all information on the hosting server. 7.5 How do I get a.sch.uk,.gov.uk or.ac.uk domain name? An internet domain name is the user-friendly address of your website. A domain name comes in a standard pattern of for schools this would be Only schools can register a.sch.uk domain name. To obtain a sch.uk domain name, an ISP requires the school s Department for Education and Skills (DfES) number to confirm eligibility. Nominet manages the.sch.uk naming scheme. UKERNA administers the.ac.uk domain (for UK higher and further education sites) and the.gov.uk domain (for UK government sites). To register these addresses, you must apply direct to UKERNA, which will require justification for their use 7.6 What are the costs of web hosting? Depending on the solution you choose, the costs of web hosting are likely to go on host equipment, server software, internet connection, user training, technical support and domain-name registration. The cheapest solution by far is virtual hosting, which can be free of charge, but which may restrict what your site can do. Becta 2004 Valid at September 2004 page 6 of 7

7 The comparison between dedicated hosting by a third party and doing it yourself depends on the facilities and technical skills already available. If your organisation already has web servers, it should also have facilities such as disaster recovery, internet connection and technical support, so the do-it-yourself option may prove a cheaper alternative. Setting up these essential facilities is expensive, however, so if you would have to do so from scratch, third-party hosting would prove more cost effective. 7 Summary Before developing your own website, you need to decide where to host it to use a virtual or dedicated host, or perhaps host it yourself. As each method of hosting has different advantages and disadvantages, consider carefully which will be most appropriate for your particular circumstances and needs. 8 Supporting material 8.1 Useful links and resources Nominet UKERNA Web Host Industry Review Internet Services Providers' Association Becta 2004 Valid at September 2004 page 7 of 7