I explained to him the problems we had been having. He then went off to the PCP to wire in the DSLAM. When he got back he said that in the cabinet one of the wires of our pair was broken and held together by the insulation, which when he touched snapped in half. He said that it may well have manifested itself as a HR fault. He seemed surprised that we hadn't heard any crackling on the line, but said that might explain a bit of the "white noise" which we had been hearing. He didn't seem to know the length of the line to the PCP, but said "I think you'll get faster speeds than 11Mbps- that's very conservative".
He then got his JDSU out, and said that everything looked OK. He then let me take a picture (see attached). The JDSU reckons a line length of 0.9km (how does it estimate that?). Apparently PN don't pay OR for a 'managed install', so technically all he was meant to do was plug the modem in and run, but he wanted to check the line speeds as well.
So this is what I am currently getting:
I would attach some BT Speedtester results, but I did one a little earlier (stupidly didn't take a SS of it) and apparently I need to wait an hour to do another one.
How come the IP profile is at 27Mbps (looking at the JDSU)- should it start at 40 and work its way down to a stable level, or am I misunderstanding something?
Sorry I couldn't get more data, I think he saw this as a very straight forward install and so didn't do much diagnostic stuff. I do hope the JDSU data is useful.
Kind Regards,
Thomas
Well Thomas, you're not stuck in limbo any more then
The engineer seemed to be quite helpul & obliging & hopefully your various line issues have now been permanently fixed.
I'm not sure about the bell wire though. Someone else may advise you to remove that???
It should take around 10 days or so for your speeds to stabilise.
Are you happy with the current speeds? They are a lot higher that your "meaningless" estimated speeds.
I'm really glad that you managed to take a photo of the JDSU showing the estimated line length. None of my visiting engineers have shown that display to me. More than one visiting engineer told me that the JDSU could not display that sort of detail when I asked them for it
I will be using your photo as evidence
(if you have no objection) when the next engineer vists me, hopefully during this week.
I believe that line length is estimated via the JDSU
mainly based upon on the attenuation figure, but more knowledgeable people than I aren't really quite sure for VDSL2 purposes. It may well take other factors such as SNR levels into account.
VDSL2 as delivered by BT, known as Profile 8c, Annexe B has the downstream split across 2 frequency bands, the lower band is more or less the equivalent of ADSL2+ frequencies, & the higher band is used for VDSL2 higher frequencies.
It is thought that the attenuation as displayed on the engineers' JDSUs must be some sort of an average value for both bands.
Some other countries use higher frequencies, with more power, split across 3 bands.
Nobody appears to be quite sure what typical attenuations for a given line length for VDSL2 purposes should be yet.
It would probably depend whether it is all copper, or part aluminium cabling. Both have different attenuation values.
Due to your actual or estimated distance from the cabinet, it is very unlikely that 40 Mb would be delivered to your home.
Others with guesstimated line lengths of around 650m & a JDSU attenuation value of around 19dB or so have been achieving download speeds of around 37Mb, more or less the full whack available, less a bit for overheads.
The IP Profile & download speeds as shown in the BT speed tester & the engineer's JDSU apparently always appears a bit more pessimistic than actual download speeds as shown by other speed testers such as speedtest.net.
Your US & DS LIne Atten values are identical, which is interesting for me as there is a large difference between the two for my line, the US being much higher. The signal attenuation is probably the more important value though.
All I would suggest is that you regularly monitor your download speeds as reported by speedtest.net for consistency, along with regular BT speed test results (save the screenshots).
If nothing else, you will have a good record of your connection's capabilities if your speeds should start to plummet outside the 10 day training period. Your speeds may well even increase over the next few days.
EDIT: Just for curiosity, which version of the modem has BT supplied for you?
It should be displayed on a sticker underneath the modem, the firmware version ending in SP06 or SP10, & the hardware version may have a 2V or 2B sticker, also underneath.
Also please see the PM that I sent to youPaul.