In the UK there are 3 types of broadband ADSL, FTTC, or FTTP. Two of these use technology that is based on the old dial up modem days! For those who don't remember this, these were the boxes that made strange beeping and whooshing noises when connecting and passing data and they blocked up your phone line as they actually made a phone call to connect. ADSL and FTTC do something similar except they use very high pitched noises which the human ear cannot hear and so there is no need to ‘dial up’ every time you want to connect to the Internet! To make sure any phone calls do not interfere with the broadband signals, filters are added to the phone line to keep voice and data ‘noises’ separate.
ADSL is delivered using a pair of thin copper cables from your local exchange to your home or business. The same cables that make your telephone work. The speed of the Internet connection is determined by the physical distance between the exchange and your building and the quality of the copper line. The lower the quality or the further away you are from the exchange the slower your connection is. ADSL can offer download speeds up to about 20Mb/s and a little under 1Mb/s upload speed.
FTTC or Fibre to the Cabinet is a mixed product that uses fibre optic cables from your telephone exchange to a street cabinet close to your home or business. From there it then picks up the same copper cables used in ADSL to your premises. The performance of FTTC is determined by the physical distance between the street cabinet and your home or business as well as the quality of the copper line. Again, the further away you are or the lower the quality of the cable the slower your connection is. There is an additional problem with FTTC though. It uses different frequencies of noises to ADSL and these do not travel so far so speed rates drop away much faster than ADSL but is much faster over the shorter distances. This is why there are so many green cabinets on the streets.
FTTP or Fibre to the Premises uses a fibre optic cable from a central ‘node’. These nodes are different from the old copper based exchanges because fibre optics can work over a much greater distance without losing quality. Openreach, the people who manage most of the UK’s communications cables, have decided to not use local exchanges but to bring FTTP connections back to a few ‘super nodes’. One of the biggest benefits from fibre optic cables to your front door is that your Internet speed will always be in line with the package you have bought as speed is no longer related to the length of cable. There are some caveats to this statement as speed is not always what it seems but that is a subject for another post!
Having explained the different broadband options, I would like to dispel one of the biggest broadband myths, blow away the smoke and ditch the mirrors!
Fibre broadband means FTTC and not FTTP! It was a marketing lie introduced 10 years or more ago when fibre came to the local street cabinet. Full fibre broadband is often used to mean FTTP but even that is not guaranteed. Sadly there are no advertising standards around the word fibre!
Broadband – BT, LLU, Exchange??
You may not know but BT are not the only people who provide broadband in the UK! The majority of the available broadband service providers use Openreach to provide the cable from your front door to your local exchange or fibre node (See the blog post entitled Broadband – What am I buying for information about the types of broadband available and how they differ). Openreach is (By OfCOM governance) an independent company, owned by BT PLC, responsible for maintaining the UK’s national communication infrastructure.
For the purpose of this post we will focus on and accept that Openreach are responsible for the majority of the local cables used to supply broadband connections in the UK.
So, let’s talk about Exchanges. Of the almost 5600 exchanges in the UK over 3100 are what is called LLU or Local Loop Unbundled. This means that providers other than BT Wholesale have installed their equipment into local exchanges in order to connect their customer lines to their own network. From a subscriber point of view this is great. It means that, for over half the Exchanges in the UK, there is a choice of service providers that can backhaul your data on to their network.
As you can see, from the very basic image your home connects to the local exchange and your data is, typically, backhauled over the service provider with presence at the exchange. Whilst there are over 200 Internet Service Provider’s (ISP’s) in the UK there are clearly not 200 service providers backhauling your data from your exchange.
Typically, you will find, one of, all, a combination of the following service providers at your local exchange. BT Wholesale, Sky, Talk Talk, Vodafone, Zen. There are other LLU operators with presence in concentrated areas, but these are the main ones. The majority of these providers offer wholesale services so ISPs such as No One can purchase “backhaul” from the local exchange to the core network (and then to the Internet at large).
No One uses several of these backhaul providers to connect its customers. Having choice means we are able to offer the best service possible and can swap customers between backhaul providers to resolve local exchange related issues if necessary.