Browse my website.
After that you can get far more detail on everything from the excellent Kitz and samknows sites, but they are not Muppets Guides, which is why I did mine. I do have links in places to important bits such as interleaving.
You do ask two specific questions I don't answer on my site
. I shall have to add the answers to it.
Market 1/2/3 is an OfCom classification largely dependent on the number of LLU suppliers at an exchange. For this purpose BT Wholesale counts as one. The pricing, and I expect some other, rules applied by Openreach are different.
To see how to identify ADSL/ADSL2+ see this Wiki page
. There have been comments that it isn't 100% accurate, but it is certainly adequate for my purposes.
My broadband basic info/help site - www.robertos.me.uk
My domains,website and mail hosting - Tsohost
. Internet connection -