Wednesday, 9 November 2011
Office Networks – What and Why?
So what is a computer network and why does any business absolutely need one?
Computing and computers have come a long way in the last 20 years, and now, no matter what size of business you are – whether it’s a SOHO (Small Office/Home Office) or a larger SME (Small Medium Enterprise) utilising a more corporate LAN (Local Area Network) – your business needs access to the internet and probably a local workgroup (multiple computers at the same location sharing files and resources between themselves) or local central resources such as a server. A computer that stands isolated and unconnected is almost an unusable resource carrying no value to the business.
No matter what size of business you are, you need your computer or devices to be able to talk to your other computers or servers within your premises or access the internet. Access to other devices on site may comprise other computers with information on them that you or your staff need to access, a network printer that is either connected to another PC or sits directly on the network or an external hard drive of varying size and type, perhaps VoIP (Voice over Internet Protocol) phones or lastly a server – supplying endless central resources and access to e-mail, internet, web resources, spread sheets, databases applications etc etc.
As a company that provides network designs of all shapes and sizes to fit any organisation I can tell you that the main drivers behind your decision to choose the particular model that suits your business are; the size of your business and your premises, the way in which you store and access your resources and information and the budget you have available to provide the quality of network access you require.
Structured Ethernet cabling provides resilient, robust and high bandwidth connectivity between any number of devices of any type within your business and is expandable to suit your growth. Typically this is provided by Category 5e cabling (steadily being replaced by Cat6 and 6a) professionally installed into the fabric of your building designed and installed to suit the nature and IT requirements of your business. On the upside of this technology it can provide almost any bandwidth but always provides the best available bandwidth for any device or number of devices. Typically, wired connections rely upon the type of network card installed in the computer and the router or switch that these connect back to, typically at the very least 10Mbps would be the minimum, and recently this has extended to 100Mbps with the possibility of 1Gbps if the correct equipment and cabling is installed. It is robust and reliable once installed and can support any size business from SOHO to corporate enterprise. If you have a server or want to access local resources from any other device in your premises then this system will provide the very best speed and bandwidth that you will require and for any number of users and computers, printers and VoIP phones.
On the downside structured cabling is relatively expensive to install and once in place is bound to the physical location that the cabling connects from and to – in a very similar manner to the way in which power outlets are installed.
This method of providing connectivity between IP devices has been revised over the years but the basic methodology has remained the most popular and reliable and is still to be found in nearly all business premises in some form or another, whether it is some lengths of patch leads strung between computers and the internet router or whether in the more formalised manner of structured cabling installed by professional firms.
Wireless connectivity has exploded over the last 10 years to the point we are currently at, where the technology is almost ubiquitous and every laptop and portable device embodies some type of wireless card capable of connecting them to a wireless network. This technology has some very positive sides and allows for a free of wires approach to working, providing that a wireless network is available and open for connection. In a small office environment a simple wireless router will allow for anybody with a wireless device to connect to the router and thus shared local resources and have internet access.
Wireless technology, in response to demand has been making steady progress in recent years enhancing the available range, throughput, bandwidth and security available. The primary standard for wireless has been the 802.11 standard and we have moved through b/a/g/n leaving a wireless connection currently capable of a theoretical 248 Mbps data rate and an indoor range of 70 metres (obstacles allowing). Security was a concern for wireless and still can be if not setup and configured by a professional IT company, and open or poorly setup security is an open invitation to hackers and thieves; particularly to be avoided is the older WEP security.
So on the up side of Wi-Fi, provided in a WLAN environment (Wireless LAN) it allows unfettered access to wireless networks, therefore allowing you and your staff to work anywhere within range of the wireless router and the more recent devices that support the latest “n” version of wireless standards can provide better bandwidth, range and security if correctly configured. Another point in favour of Wi-Fi is the cost of using wireless networks – for a simple implementation the cost is negligible as laptops come with the required technology, wireless USBs for PCs are cheaply available and wireless routers are barely any more expensive to buy than non-wireless routers.
On the downside wireless devices provide very low bandwidth and slow connectivity to the router compared to the wired connectivity offered by a structured cabling approach, also contention is direct, whereas if two people connect to the same wireless connection then they will have to share that connection directly therefore effectively halving their available bandwidth and this effect is cumulative as more people connect to the router. Also, wireless connectivity only provides for half-duplex as opposed to the full duplex connection of wired cabling; what this means in real terms is that a full duplex connection allows for send and receive traffic to operate at the same time, much like we as human beings can hear and talk at the same time. With a half-duplex connection send and receive has to happen separately, therefore to maintain the analogy you would have to listen, then talk, then listen etc. only able to do one of these at any time.
Therefore, for the odd one or two devices a wireless connection has many advantages particularly cost and the flexibility to roam around the premises and maintain connectivity, assuming that you are in range, however if you sit at the same desk all the time then a wired connection way outweighs the advantages of mobility as it is suddenly not a requirement. Also, expect performance to be generally poor – in comparison with wired – which will markedly decrease as more people utilise the same network connection, particularly if the connection is for more than simple internet access, for instance if you are trying to access local shared file or server resources.
There are two other possibilities or combinations for networking. The first is the cheaper HomePlug solution which utilises a combination of wired Ethernet cabling and your ring main electrical circuit. With this solution each plug has a standard Ethernet RJ-45 connector and can be plugged into a wall plug near your router and then plugs can be used wherever you want network access and each one connected to your computer using a standard Ethernet patch cable. This utilisation of your electrical ring main as your network significantly reduces the cost of providing a network for your business and can provide a theoretical 200Mbps, a significant improvement on wireless and comparable with a traditional Ethernet structured cabling bandwidth, although in reality nearer to 100Mbps would be nearer the true mark.
This is a good solution for a small business that does not want to invest in a full blown structured cabling solution but wants good quality connectivity not presented by wireless technology, and as the cost is purely for patch cables and the plugs themselves this really is a cheap and practical alternative.
Lastly, we have an option that utilises structured cabling with wireless to provide a Wi-Fi solution that is typically aimed at organisations wanting a wireless solution that covers a larger physical area, such as a multi storey building or one with a larger floor area; perhaps an organisation that wants wireless for visitors in its meeting rooms or reception areas or hotspots around a large building.
This concept requires structured cabling being delivered to points around a building where a wireless AP (Access Point) would be fitted, and therefore provide wireless access to those targeted areas. The advantages of this are that you provide a targeted Wi-Fi to specific areas of your building which provides good quality reduced-contention wireless not affected by range or obstacles such as walls etc.
Unfortunately, although this is a very good quality solution to specific needs of an organisation it is an expensive solution and more appropriate to larger businesses.
Here I am returning to my initial precept of what factors define a business’s requirements for a network and what sort they require.
In this review I have covered four concepts of networking: structured cabling, wireless and combinations which covered HomePlug and access point wireless and tried to give some basic information and guidance on uses and costs.
Structured cabling allows for the business that really uses their network for high bandwidth applications and large amounts of local access such as those who have server environments or who share large amounts of data locally and who want good quality bandwidth access that is robust and relatively maintenance free and have a relatively large budget to cover the install setup costs. Wireless access allows greater flexibility and low cost networking but at the price of much lower performance of the network and certain complexities over the correct setup of that network. The combinations are two ends of the spectrum, with the HomePlug solution offering a reasonably decent quality bandwidth solution – in-between wired and wireless - for a low cost, which is suitable for small businesses who are not ready to take the step towards a fully cabled implementation but require better performance than wireless offers for a small number of devices. Lastly we have the AP offering which is the highest cost solution for specific business needing to offer wireless in select areas of a large building without degrading that wireless performance.