Crosstalk

Is it normal to loose 20 meg due to crosstalk. I have now been on fibre for just over 18 months. When first connected speed was 79 meg down and 20 meg up
which I had for some months. I was told that I was the first to get fibre on the our cab. Over the last 15 months or so my speed has dropped and is now 56 down and 15 up and is still going slowly down. I am with PlusNet and they tell me that the BT checker says my max speed is 56 meg down and there is nothing they can do about the speed loss even though I was getting the full 80/20 to start with. Line checks come back with no faults.

Edited by deleted (Sat 28-Jun-14 14:15:01)

The BT Wholesale checker should give a range of speeds, what are the speeds it shows?

20 Meg is possible through crosstalk, unlike ADSL2+ crosstalk was always going to be a larger issue particularly in cable bundles where almost everyone has ordered the service.

Thanks Mr Saffron for your answer. The BT checker tells me on a clean line speed. High 74.5 Low 56 .
I have checked with my neighbours who also have fibre and they are getting speed in the low 70,s

Luck of how the lines sit in the cable bundles, i.e. your line might be in the middle of four lines with VDSL2 and theirs on the outer edge of the same 100pr bundle maybe.

We have seen others very close to cabinets see even larger drops, but they were close enough to still retain the full speed, i.e. might have managed 100 Meg before if the line had been uncapped.

Thanks again for your answer. It would appear then I will have to put up with it for the time being and hope that BT will start using vectoring in the very near future.

I think vectoring is likely its a matter of when in my opinion.

Its too much in the open about crosstalk, dispite locking of the modems etc. they havent kept it hush hush, and dropping speeds have now even reached watchdog.

I have been using my own modem from the start and can see the stats

Yep. From 98Mb maximum as 1st connection on the cabinet to 71Mb here.

I was first on my cab also.

109Mb max down to 98mb so far. So not as big a drop. My SNR was 15 up until a few days ago when it dropped to 11.5 as well as the max attainable speed dropping from 103 to 98mb in one day, Don't think thats down to crosstalk tho

In reply to a post by Ignitionnet:

Yep. From 98Mb maximum as 1st connection on the cabinet to 71Mb here.

I think mine originally had an attainable of 91. After twelve months It had stabilised at 65 with interleaving. Then the modem firmware update a few months ago gave it a boost back to 69 and got rid of interleaving. It's been steady as a rock since then.

Just be glad you haven't lost 20meg when you started off with 53 like my line, I've gone from 53 down to 31. So percentage wise I've lost over 40% due to it which is annoying to say the least.
Always someone worse off than you though so I can't complain especially when I was on 2meg 6 months ago.

Could be different uptake levels - there are over 280 lines connected to the Huawei here.

In reply to a post by IranianGiraffe:

Just be glad you haven't lost 20meg when you started off with 53 like my line, I've gone from 53 down to 31. So percentage wise I've lost over 40% due to it which is annoying to say the least.
Always someone worse off than you though so I can't complain especially when I was on 2meg 6 months ago.

I'm lucky then. 20 months ago I started FTTC and today still have the same sync. I guess my neighbours are virgin customers or ADSL is good enough for them (average 12meg here).

It'd be worth changing your vdsl2 interstitial faceplate to a mk2.
I had similar drops in speed in a couple of locations and the mk2 faceplate along with a short twisted rj11 patch lead my speeds more or less recovered. http://www.ebay.co.uk/itm/221465010788

http://www.tandyonline.co.uk/high-speed-rj11-dsl-cab...
Obviously try to site the vdsl 2 modem within 1m of the master socket.

Edited by deleted (Sat 28-Jun-14 23:14:10)

I think anyone at 40% or mor eloss is on the worst end of the trend.

Mine is also around that %.

110 when I first checked my stats, the lowest I seen whilst on fast path was low 60s. (not going to post interleaved figures as thats not like for like, thats artifical reduction by DLM). My line then got back to above 65 before syncing at 75 1am one morning about 9 or so weeks ago at a 4db margin, I am still on that sync now with 75mbit with a 3.9db snrm.

Its not necessairly about number of enabled lines but rather if a big disturber gets enabled. I had it seems 2 big disturbers enabled within a month of my service been installed and I was first on the cabinet, so arguably I was incredibly unlucky. Within a month of install down from 110 to 73. Since then any further drops in speed have been in small bites.

Of course I am also lucky that most of my loss of speed is above the 80 cap so not 40% loss of throughput.

Edited by Chrysalis (Sun 29-Jun-14 00:50:00)

I think BT Wholesale checker should including Clean A, Clean B and Crosstalk expecting, so the customer will know before signing up. Example below eg:

FTTC Range A (Clean) 80 77 20 19.9 -- Available
FTTC Range B (Impacted) 80 67.3 20 17.9 -- Available
FTTC Crosstalk (Clean) 80 57.3 20 17.9 -- Available
FTTC Crosstalk (Impacted) 80 47.3 20 15.9 -- Available

Edited by adslmax (Sun 29-Jun-14 01:10:51)

I think clean already is with their expected crosstalk. Which is why many people have managed to sync much higher than their estimates.

I think its happened to me too.

I started off with around 75mb line... now dropped to 61 which I think is about a 18 - 19% drop. I think this could be because there are a lot more people on FTTC now.

On the BT website, the range says that I should be getting between 69 - 80. But I'm just wondering Is it really worth it guys to chat to BT about this as it's under the range by 8mb?

I had FTTC since February 2014 and still on 79.9 Sync 19.9 Sync as someone saying my cabinet is about 3% users on it at the moment. I start off with 113,000Mbps but now gone down to 92,000Mbps

Saw my line drop to 74/15Mbps the other day. A reboot got it back to 79/20Mbps. It's a worry that this is the limit of my line currently when you consider that I'm only 80~100 meters from the cabinet in a new build so all new lines nothing overhead.

In reply to a post by aavid60:

Is it normal to loose 20 meg due to crosstalk. I have now been on fibre for just over 18 months. When first connected speed was 79 meg down and 20 meg up
which I had for some months. I was told that I was the first to get fibre on the our cab. Over the last 15 months or so my speed has dropped and is now 56 down and 15 up and is still going slowly down. I am with PlusNet and they tell me that the BT checker says my max speed is 56 meg down and there is nothing they can do about the speed loss even though I was getting the full 80/20 to start with. Line checks come back with no faults.

Nearly 3 years ago when my cab went live my max attainable was 130Mbit, its now 110Mbit

As discussed elsewhere, I started on 56Mbps actual and 4 months later am on 32Mbps actual... Clean estimate is 43 - 32 Mbps

In reply to a post by Chrysalis:

I think vectoring is likely its a matter of when in my opinion.

But will it be for all, bearing in mind ECI kit will need the M41's replacing to support vectoring.

In reply to a post by Alnath:

Nearly 3 years ago when my cab went live my max attainable was 130Mbit, its now 110Mbit

Oddly i have noticed mine has crept back up to 116Mbit.

I have a similar Issue.

When I first started out I had a solid 75mb line.

Now I get 53 tops. I can only assume that this is because of crosstalk, as I'm about 200 - 250m away from the cabinet.

I had an engineer out and he said that there was a woman in his area that gets the full 75mb, but as soon as the clock hits 8pm, her speed drops to 9mb.

He believed that it was something being switched on at that time which was effecting the speeds. He said that electrical appliances being used that don't have the Kite mark can be a possible issue too. Don't know how true it is though!

In reply to a post by DarkKobra1977:

When I first started out I had a solid 75mb line.
Now I get 53 tops. I can only assume that this is because of crosstalk, as I'm about 200 - 250m away from the cabinet.

Are we talking sync speeds or download speeds?

It is possible.

http://www.thinkbroadband.com/videos/broadband-inter...

Shows using an AM radio, though for VDSL2 might need to shift into the shortwave bands, since VDSL2 is 1 MHz to 17 MHz

Appliances with the full Kite/CE marking can still cause problems too, i.e. the marks are only from a sample that is tested, a bad batch or single poor solder joint can cause issues.

In reply to a post by DarkKobra1977:

I had an engineer out and he said that there was a woman in his area that gets the full 75mb, but as soon as the clock hits 8pm, her speed drops to 9mb.

That sounds more like a wireless issue than a connection speed one.

Edited by RobertoS (Sat 16-Aug-14 12:48:48)

This is Sync speed sorry, forgot to mention!

It could be DLM

My experience over 30 months is this;

a. First on the cabinet according to the engineer: 104.2Mbps max attainable.

b. Fell slowly over 2 years to 93Mbps.

c. Lift and shift in March 14 - dropped to 84Mbps.

d. Two periods of maintenance last week and a fault requiring an exchange line card change: downstream speed has dropped to 80.6Mbps.

According to GUI, I am still on Fastpath, INP 0 and no interleaving.

In reply to a post by MrSaffron:

Appliances with the full Kite/CE marking can still cause problems too, i.e. the marks are only from a sample that is tested, a bad batch or single poor solder joint can cause issues.

It's worse than that. All these quality frameworks have the concept of self-certification. If inadequate quality most likely wouldn't directly cause death or serious injury then it's not worth the time and expense to insist on oversight - so the manufacturer applies the mark on their own authority and the first time an independent assessor would check it is if there's a formal complaint. Until / unless that happens to them nothing stops makers or importers fixing the mark without doing any tests at all. Of course if they get caught they could get a fine or even do time, but that's not likely. EM shielding is definitely the sort of thing cut price manufacturers won't test properly even on a sample item.

Not every kind of CE mark can rely on self-certification, a CE marked pacemaker for example has to be tested by an independent third party, but "low risk" things like a beer fridge or a mobile phone charger are usually self certified and thus their quality is indeterminate. You are of course entitled to a full refund if you buy something that's unfit or not as described - and a CE marked item that wouldn't actually pass qualifies as both - but in my experience on very cheap unbranded junk where the problems are most likely people throw it out when they notice a problem rather than trying to get a refund.