Buyer’s Guide to Business Broadband (2013)
David Barker of 4D Data Centres, demystifies the different broadband options available for small businesses
For some businesses internet speed is not vital but resilience is. While for others having a fast connection is more crucial than it being available 24/7. Choosing the right connectivity option ensures you get the right spec for your needs and your budget.
ADSL (Asymmetric Digital Subscriber Line)
Asymmetric Digital Subscriber Line (ADSL) is a line that permits simultaneous transit of data and voice calls.
ADSL uses frequencies which are not used for voice calls across a copper telephone line, so it allows you to have a data connection at the same time as a voice call; although this does require a filter to be installed to ensure they don’t cross-over.
ADSL has enabled widespread broadband across the UK. It’s affordable and doesn’t require large setup costs so it’s the most common connection for homes and SMEs.
Bandwidth downstream from the provider is faster than upstream to the provider and the speeds you experience are highly dependent on the distance you are from the telephone exchange – the further away the slower the connection.
Bonded ADSL comprises two (to a maximum of four) ADSLs which come into the provider as two separate lines and are combined to provide a larger speed and bandwidth connection.
Although bonded ADSL can provide greater speeds, it doesn’t always provide greater resilience. You still require one router in your office for all the lines to connect into and all your ADSLs will likely go back into the same exchange which introduces a couple of points of failure. It is possible to have two ADSLs bonded across different exchanges, but having a large difference in the length of the two wires could also introduce instability.
If resilience is key, then I would recommend two separate ADSLs to separate exchanges over a bonded connection to one exchange. If the two separate lines are with the same provider then you may even be able to load balance across them to get some speed improvements.
FTTC (Fibre to the Cabinet)
The options for FTTC are dependent on your location. There is currently a national roll-out of fibre services to street cabinets, however the majority of these are within major metropolitan areas with a lot of rural locations still being underserviced.
The main difference with FTTC over ADSL is the shorter length of copper phone line that is in use. With traditional ADSL your phone line goes to the street cabinet as copper, and then stays on copper lines all the way back to the exchange. With FTTC you still have a copper phone line to the street cabinet, but from the cabinet back to the exchange uses fibre, which is a lot faster and more reliable than a long copper line.
FTTC offers a good balance between cost and speed, where it is available, and is the most logical next step from ADSL for most broadband users.
4 Leased Lines
Leased lines are high speed connections that are fully synchronous (you get the same speed downstream as you do upstream) and typically come in speeds from 10 Mbps to 1 Gbps. You can go higher than this, all the way to multiple 10 Gbps, although these are typically specialist requirements.
Leased lines work on a similar principle to FTTC, but rather than the fibre terminating in the street cabinet it will terminate in your building on a device called a network termination unit (NTU) which means that there are no copper phone lines in the connection at all.
A leased line will typically also have a far more stringent service level agreement (SLA) covering at least the minimum uptime, response times and fault resolution times, but you can also find SLAs covering latency, jitter and minimum speeds. This makes leased line connections ideal for video and for companies which need to move large amounts of data on a regular basis.
5 MPLS (Multi-Protocol Label Switching)
MPLS is not strictly a broadband connection in the way that ADSL or FTTC are; however it is a term that is used a lot in business connectivity and many people are confused by what it means.
MPLS runs over the top of one of the connections described above and essentially enables you to have Quality of Service (QoS), service level agreements on the delivery of data and ’any to any’ connectivity.
QoS allows you to prioritise certain data types over others. This means that if your connection is congested then your ‘high priority’ data will be delivered first and can also be combined with an SLA that ensures certain data (for example, VoIP) has a minimum amount of bandwidth available so that your calls can always go through.
MPLS also provides a way for you to connect multiple locations with different types of connectivity. You can have a small office on an ADSL line, a warehouse on FTTC and your head office on a leased line with all of these connections within the same MPLS. This allows them to communicate with each other as if there is a private network in-between the offices and also puts in place the QoS/SLA features for intra-office traffic.
If you have any questions about the different types of connectivity, please drop me a line on @david_4D using the hashtag #connectivity.