Quick answer to most of your questions is NO NO NO
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Hmmmmm. sounds a bit MUXed up to me
(sorry couldnt resist the pun and I hope at least one person gets it
)
The most likely explanations is that it was an LLU MSAN.. in which case certain LLU ISPs have their own techs who work on their own MSANs (such as sky). Demarkation would be the inspan handover point.. and their techs can work on anything past this point which belongs to them.
I may be wrong, but Im pretty certain that I read something somewhere that for any of the LLU's who contract their own techs... all this documentation is set up during the time of installation of the LLU MSAN, and a contract formed between BT and the LLU as regards to access rights.
However... anything between the handover and the customers NTE in the home belongs to BTo.. and only BT (or BTs own subcontractors) can work on that equipment.
>> DSLAM had been plugged into aluminium wiring!
More possible Muxedupness - most likely that some part of the wiring between the exchange and home was found to contain aluminium... which isnt that unusual.
Most lines that have alum on them are already marked, but there are new ones that crop up from time to time and some are only discovered when the owner gets adsl for the first time.
Inside the exchange its fibre and copper... theres no way this could possibly happen between the MDF and MSAN/DSLAM