BT Wholesale has announced that it is cutting the minimum broadband download speed supported by its next generation "super-fast" Fibre-to-the-Cabinet ( FTTC ) service from 15Mbps (Megabits per second) to just 5Mbps. The move is designed to "increase the footprint" (UK coverage) served by FTTC.

FTTC delivers a fast fibre optic cable to BT's street level cabinets, while the remaining connection (between cabinets and homes) is done using VDSL2 (similar to current ADSL broadband but faster over short distances) via existing copper cable; FTTC can deliver speeds of up to 40Mbps, rising to 60Mbps in the future (uploads can reach up to 10-15Mbps).


There is apparently no change to the fault reporting journey for circuits provided below 15Mbps. The phone line fault threshold for a 5-15Mbps circuit is 5Mbps, while a circuit that normally runs at above 15Mbps would naturally have a fault threshold of 15Mbps.

On the surface this is good news because it will allow BT to deliver faster connectivity to homes and businesses that might previously have only been able to receive the very slowest of speeds. Under the existing threshold such premises would not have been able to get FTTC, even if their cabinet had been upgraded to support it.

However a minimum speed threshold of 5Mbps is admittedly below the present national average of 5.2Mbps recorded by Ofcom's May 2010 data on existing infrastructure. As ever there will be those who would say this is a step backwards instead of a proper 100Mbps FTTH infrastructure, although for many people it will still bring a huge improvement.

UPDATE 26th November 2010

We've contacted BT to get some questions clarified, such as why the fault thresholds appear to differ from what FTTC offered at its launch, and have just had a reply. Apparently the throughput fault thresholds for the above 15Mbit/s FTTC service were increased to 12 and 16Mbit/s recently.

However for end users that come onto the FTTC service with a sync speed of 5Mbit/s or above the fault threshold will be set at 70% of their line rate. So this means if someone has a FTTC service which syncs at 10Mbit/s and the service slips to 7Mbit/s the CP can report it as a fault.


There are now two variants of the FTTC service. One with a minimum assured speed of 5Mbit/s and one with a minimum assured speed of 15Mbit/s.