black sheep I am still intrigued by "faulty ports".
As I understand an engineer to do a port swap (lift and shift) has to swap the tie pair, because they have no access to the fTTC cabinet. So these are been diagnosed as faulty ports, but it could be a bad tie pair?
Doesnt it sound odd that these cabinets which are of course expensive would have failing ports at such a high rate?
How do you normally diagnose a bad port, what are the signs? You noticed my posts lately showing a weakened D1 signal? which is the frequency under very low attenuation.
A local engineer diagnosed my issue as bad pairs rather than faulty ports. It seems tho he could have easily diagnosed it as bad ports instead.
If you diagnosing 1 a week bad you will eventually run out of ports in 2 years 
Chrysallis
Your assumptions are bob-on. Even if it's just the actual tie-pair that is faulty, we have to be provided with a brand new port (Lift & Shift).
On a couple of occasions, I've been on-site at a notoriously 'bad Cab', when one of the PCR Engineers turns up. His remit will be to have a look at a handful of 'Faulty ports' that have been given to him, and he will then determine if it
is actual ports at fault, or actually just poorly terminated cables/split-pairs ?
You ask how we diagnose a bad port ?? Very basic, crude techniques really. We certainly won't go viewing individual band-plans as a normal practice, (don't shoot the messenger -- shoot those that dictate what we are told to do and how long we have to do it in)
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In simple terms, a 'bad port' will only be diagnosed as such for a relatively few types of instance. A) No synch, B) Extreme errors, C) Dropping connection, D) No PPP Session (if the 'build' on both Openreach and BTw's sides, are correct). There may be something else, but off the top of my head, I can't think of anything else ??
I, and probably many other engineers, have visited EU's that have had 20-30 engineering visits and no fault can be found. Some of these visits will have seen tests done to 'Precision Test Officers' standards (X-Talk - Impulse Noise etc), but still the DLM will drop the speed on a daily basis, after a reset.
I have personally (along with another frustrated engineer), been involved with two such cases, and both were what you would call long'ish lines. By the time we'd finished over the months, the EU's had basically had a new circuit spun from gold, but still the same DLM action would see the speeds drop day in, day out.
Only by arguing vociferously with our colleagues at the NGA helpdesk, did we manage to get 'New ports' issued on both circuits. We have not (touch bl00dy wood), heard from either of them since !!!
Point I'm labouring to make is, maybe it was a very miniscule weak connection on the tie-pairs having some affect on the band-plans ?? Or, maybe it was indeed a faulty VDSL port that to all intents and purposes, tested absolutely fine with all we would chuck at it ??
In closing, to get a 'Lift & Shift' done on ADSL is hard, but on VDSL it's easier to get an audience with the Pope. They certainly aren't done lightly.
