SDSL? ADSL? EFM’s? Fibre leased lines? We are here to help!

SDSL? ADSL? EFM? Leased Lines? The world of business internet acronyms can be a confusing one and we often get asked what is the difference between SDSL, ADSL, EFM’s and fibre leased lines. So we thought we would create a simple guide to help you understand all the connectivity Jargon you get bombarded with.


SDSL stands for symmetric digital subscriber line. The service itself is on the decline due to it being copper based and all the fibre options that can offer a more stable and reliable bandwidth.We expect SDSL to be extinct in the near future due to more cost effective solution that are available on the market. SDSL can provide your business with up to 8Mb up and down speeds and prices usually start from around £400 per month upwards. This is an uncontended service so your business would be the sole user should you go for this option.



ADSL stands for asymmetric digital subscriber line. This is the cheapest internet solution with some prices starting from as little as £20 per month.ADSL does have some drawbacks that prevent a lot of internet reliant businesses opting for it. It is contended so you will be sharing the line with other users. This means at peak use times you may experience slow or lagging internet connections. It is also not symmetrical so you download speed may be up to 24Mb but your upload may only be 1Mb. Its also run on copper wires so the service degrades over distance meaning you may need more than one ADSL line to give you the bandwidth you require.You would normally have to share the service with up to 50 other users.



EFM stands for Ethernet first mile and means exactly that – the first mile of the line is fibre and the remaining is copper. We see EFM’s as a good in-between service, like a hybrid of ADSL and Leased lines. Prices are usually starting from around £200 per month for an EFM depending on location and this will give you up to 24Mb symmetrical upload and download speed.  Should you take out an EFM you would be the sole user so you wouldn’t experience any lagging during peak times like the ADSL lines. Also if you are a SME and only require 10Mb or 20Mb bandwidth then an EFM can save costs associated with fibre leased lines and give you a very similar service.


Fibre Leased Lines

Fibre leased lines are rapidly taking over the copper infrastructure for delivering internet across the UK. The lines are made entirely of fibre optics which means faster speeds than the traditional copper. Prices start from around £300 per month again depending on location. With leased lines you can achieve much higher bandwidth anything from 10Mb to 10Gb. It is also an uncontended service so no lagging or downtime. A big benefit to businesses for having leased lines is the service level agreement that the providers give. Most are above 99.97% meaning you are guaranteed that level of connectivity and bandwidth, should it fall below that you can start claiming money back from the ISP! They also provide fix times which is usually under 6 hours and first line support.With leased lines they are also a good option to run VOIP call systems through, if this was done through an ADSL for example there’s a good chance the lines would go down at peak usage times, whereas having your own leased lines eliminates that issue.This is a service for businesses that are heavily reliant on their internet connectivity.

SDSL? ADSL? EFM’s? Fibre leased lines? We are here to help!

So weather you have SDSL or are looking at a leased line we can help you not only get the best prices but also understand the big differences between all these services. If you have made it this far thanks for reading and we hope this guide helped you out. If you are on social media we would love for you to connect with us and we always follow back –

Linked In





Leased Line Form

10Mb to 10Gb Leased Lines

30 Seconds Enquiry Form