The “new” BT FTTC checker (http://www.superfast-openreach.co.uk/where-and-when/ <http://www.superfast-openreach.co.uk/where-and-when/>) discloses information about the inside of datacentres.
It appears to contain a list of all the locations BT have on database as having a POTS line. For example, a search for Telehouse’s postcode yields something like https://www.dropbox.com/s/xh6yrprwvanbb1m/BTOR.png You might like to see what information it yields about your sites.
