You'd have to ask Sky, which can be time consuming on the phone, and expensive if my experience with my Sky TV service is a good measure. They sell their "Sky Broadband Unlimited" package, and can define what it is, and change it within the terms and conditions they ask you to sign when you move to them.

The primary difference LLU makes to an exchange, is the presence of non-Openreach equipment which is directly connected to the wires back to peoples' homes, and hopefully the associated backhaul arrangements. That way, if there's congestion, a single operator is responsible. Zen, who have not unbundled the exchange, have to involve Openreach and use tools which Openreach provides them with, to diagnose congestion over virtual circuits back to Zen's core network.

There are companies who sell "wholesale connectivity" access to last mile Openreach infrastructure (ADSL and VDSL for example). This would make it cheaper for a new ISP to get access to Openreach or anyone else's infrastructure in the last mile via a LLU exchange, without unbundling the exchange themselves. They charge for this of course. I met one of these companies at the INCA Rural Broadband seminar a week or so ago - if you're interested How many slices of pie are there now between the internet and the customer, and this all gets passed down to the end user?

The complexity involved in backhaul, and the congestion vs profit conflict, makes this market fiercely competitive. This doesn't motivate the ISPs to reveal much to their customers. Sometimes, they can't, as they don't know themselves. The current DEFRA tender which KCC are expected to award in April, is protected by commercial NDAs. We won't know what, who or when, until the winner decides to reveal what they want to reveal. The simplicity of a community owned network ISP, with enough fibre-optic bandwidth to make all the discussion of Mbps/mph/cabbages irrelevant, is where the future must be. B4RN have done it ... and we want to also!