EFM Speeds - What To Expect
EFM speeds vary widely by location. The maximum speed you can get will depend on several factors, including how far away you are from your local telephone exchange, and which wholesale EFM network operators have equipment in that exchange.
EFM is mostly provided using multiple pairs of copper wires. The more pairs of copper wires used, the higher the total transmission speed.
EFM Speeds Are Affected By Which Local Telephone Exchange Serves Your Site
The UK has 5600 telephone exchanges. Only around 3000 have the equipment required for EFM services. TalkTalk has its EFM-enabled equipment in around 3000 exchanges, BT Wholesale has it in around 1800.
The maximum speed offered to ISPs by those two providers differ. TalkTalk Business offers to use two or four pairs of copper wiring. BT Wholesale uses between 2 and 8 pairs. So the maximum speed available in most exchange areas is 20Mbps. In the BT Wholesale EFM coverage area, the maximum speed is 35Mbits.
Bear in mind that you're very unlikely to achieve those maximum speeds as...
EFM Speeds Are Greatly Affected By The Cable Distance Between Your Site and the Local Telephone Exchange
The longer the distance, the slower your EFM circuit is likely to be.
Bear in mind that we're not talking about your distance from the exchange as the crow flies, but the cable distance, which takes a more circuitous route to your site.
EFM connection providers should be able to give you an estimate of whether particular speeds are achievable at your specific location.
Call Us To Find Out Your EFM Options
In truth, getting an EFM leased line isn't as attractive an option as it once was. Fibre leased line prices have fallen significantly, making fibre relatively more attractive in many cases.
Fibre doesn't have the same bandwidth constraints as EFM, offering speeds of up to 10 Gbit/s in much of the UK.
Call us on 020 7847 4510 and we can use our EFM checker and fibre leased line pricing tools to check which options are available at your location - and find out which speeds are potentially available at your site.
For example, at our office in London, at the time of writing, our EFM availability checker tell us we are 920 meters away from the Wapping telephone exchange. It also tells us that 2 pairs of copper would be likely to deliver 7Mbps of bandwidth (5Mbps of that guaranteed). 4 pairs would be likely to deliver 14Mbps (11Mbps of that guaranteed). Obviously, using 8 pairs could double those speeds.
We can also see that TalkTalk has issues with hitting its target delivery times (rating the exchange as 'Amber' out of Red/Amber/Green), and estimates a delivery time of 90 working days (rather than the 'from' 25 or 30 often touted in EFM providers' marketing).
So, for all the talk of EFM delivering up to 35Mbps or 20Mbps, it pays to have us check the speeds available at your particular location. It may be that an EFM internet connection can't deliver the speeds you're after.
Why we don't offer an EFM speed checker online
We used to offer one, but we found there was a big problem: Around 50% of visitors that tried it couldn't get EFM where they were, and even when they could get it, the speeds available were nowhere near the 20Mbps or 35Mbps often touted.
As a result, we switched to offering our standard leased line pricing tool on pages such as this one. It checks fibre leased line availability, and EFM over copper availability, comparing wholesale quotes to figure out which option is best at each location.
Consistency of EFM Speeds
Most EFM circuits are dedicated, meaning that bandwidth is solely reserved for you all the way from your site to your ISP's core network. You don't need to fight other customers for the same bandwidth. As a result, your throughput shouldn't drop at peak times when lots of other firms are using their connections at the same time.
EFM is underpinned by DSL technology. Not ADSL, but something that's similar to its symmetrical version. Like ADSL, it's based on sending electrical signals over copper wires. So data transmissions may potentially be impacted by electromagnetic interference - including crosstalk from nearby phone lines, radio transmissions and flashing Christmas tree lights. To put it another way, even in the absence of network contention, issues with the underlying circuits may reduce data transmission speeds.
That's why, in our example above, the EFM connection speed TalkTalk thought they could provide to our office (11Mbps) and the speed they were willing to guarantee (7Mbps) were so different. Fibre leased lines don't have this problem. If you ordered a 20Mbps leased line, you'd get 20Mbps, no question.
To learn more about EFM, including the speeds we think you can get, call us on 020 7847 4510.
