In general, FTTC (VDSL) will extend the reach of broadband, because it effectively shortens the length of the connection by the distance between the street cabinet and the exchange (by at least 3km in Ewhurst). However, this does not help those a very long way from their cabinet or connected directly to an exchange. Nor does it remedy any deficiencies in the line between the cabinet and the property. In many cases, it is the quality of the copper and/or aluminium connection to the cabinet which has the greatest impact on broadband performance. Therefore, there is no straightforward answer to this question.
If we use Mark Heath’s VDSL2 graph (here), then superfast downstream connection speeds of 24 Mbps or more can theoretically be achieved on line lengths of up to 1.2 km, and from around 1.6 km performance is identical to ADSL2 (N.B. Mark says “the graph is very much based on a good quality copper line”). More realistic performance estimates from ThinkBroadband can be found here. With ADSL services, the relevant line length is all the way from the (Cranleigh) exchange, but with FTTC it is the distance from the cabinet which matters. My line length is recorded as 6.6 km (from the exchange), and engineers have told me that this includes sections of old, corroded aluminium cable, poor joints and failing insulation. Therefore, I was probably lucky to achieve around 1.7 Mbps after optimising the ADSL connection with Walter’s help. My speed estimate for FTTC (obtained here) was 4.6 Mbps. The line length from my cabinet should be about 2 km if it follows a reasonably direct route, which could give me up to 16 Mbps from FTTC using Mark’s graph. We assume that the large difference is due to the poor quality of the cables and joints, and possibly some external interference from power cables. In reality I achieved 5 Mbps download sync, two months after VDSL installation in December 2012. This deteriorated to under 4 Mbps then increased to 5.6 Mbps following a line repair and ISP intervention.
Anyone much more than 1km from their street cabinet in Ewhurst should consider themselves furtunate to achieve the “superfast” broadband minimum of 24Mbps using FTTC, depending on line quality and cable route. Those with lines up to 1.5 km may reach the SCC target minimum of 15 Mbps. Beyond that, speeds achieved so far here in Ewhurst seem to drop off much more rapidly than expected, and are highly variable.
Openreach provide the following guidelines from national results: Premises up to 200 metres from cabinets get 50+ Mbps; those up to 500 metres achieve between 25 and 40 Mbps; up to 900 metres they achieve from 15 – 25 Mbps; the minimum 2 Mbps service reaches out to 1.2 miles.
Learn more at the following links.