As Adam says, we are currently looking to seek clarification from Openreach via our BT account manager at Wholesale.
Using a wasps nest as a Piñata is one of my specialities, so don't expect this to vanish, just expect it to go quiet for a while.
The external NTE is a popular unit in new builds, but not in all cases. It's popular as it removes significant risk to BT and places all aspects of the telecoms build on the property builder.
The nature of this unit means it can't contain a test socket due to risk of use as a phone circuit, or at least reduction. The problem is testing is more problematic for things such as DSL.
Phone testing is pretty simple.
1: Use alternate phone to test the device itself
2: Isolate the phone to test the internal cables
3: Finally pull the yellow plug on the NTE to prove to the BT network.
However with DSL, testing alternate equipment is possible for point 1 yet points 2 & 3 cannot be reliably performed on DSL levels.
Openreach SFI engineer do perform what is known as a "Uplift to NTe5 for Broadband use". This is non-chargeable and performed in cases where the existing NTe5 is proven defective (and not at a result or wilful/accidental damage or wear'n'tear) or an older master socket is in use (see the older LJU sockets on the Kitz page listed at the top).
Both aspects prove hard to eliminate internal cabling on, because they would require you to essentially tamper with the BT network. Something I certainly do not recommend.
I suspect that such an uplift might apply to an external NTe, though the difference here is the site of the NTe.
With regards to charges in circumstances of a Uplift to NTe, if we book the engineer to investigate internal cabling, charges would apply if the uplift works and then goes on to show a secondary internal cabling fault. If we do not book in the request for internal cabling, a secondary fault will not be tested and would leave the remit of checking the internal cables back on the customer, using the newly supplied test socket.
In cases were we do arrange the internal cables to be checked, this secondary fault investigation is chargeable, whilst the uplift isn't. This would be part chargeable to the customer.
