Rogue Sky Box

tehidyman · Jun 20, 2011, 15:08:23

For a few years I have been trying to identify the causes and cures for the RF noise I experience on my broadband. I eventually tracked it down to the bungalow opposite. When he was away for a few days my margin shot up only to drop when he returned. Using RouterStats I noted that there was often a big jump in margin around 10.30 to 11.00 in the evening. I can readily see his TV now the light evenings mean we don't draw curtains till late. Yes, when he turns the TV off my margin goes up and when he turns it on it goes down. Typically between 5-7db change. I have established that he has Sky. Searching the Internet I have found that a) it could be a faulty box (but it works fine), or b) nothing can be done about it, or c) he has not installed a filter. As he is not technically minded what filter could I offer and where should it be fitted? Is this a likely cause/cure? Has any one any other solution consistent with good neighbourly relations?.
All contributions gratefully received

.Griff. · Jun 20, 2011, 15:30:28

You say there's a big jump in margin at around 10.30pm to 11.00pm when he's watching TV and you suspect it's a faulty Sky box but Sky boxes are generally on 24/7. Perhaps it's the TV itself at fault?

Rik · Jun 20, 2011, 16:37:57

I agree, Griff. The only suggestion I can make, if he's amenable, is that you take a MW radio over there and explore the TV.

tehidyman · Jun 20, 2011, 17:55:18

Thanks Griff and Rik for the input. Having changed my search direction to TV interference it seems that neighbours' large plasma TVs are reported to cause the problem especially when connected to a Sky box. However as the problem is a reduced sync and not a loss of service I assume from posted comment elsewhere that I may not get any help from my ISP (IDnet) unless I move to BT and then not sure if they would help.
From replicated observations of his TV and my RouterStats I am certain it is precisely correlated with his TV switching on and off so what progress could I make by proving it with a MW radio?

Rik · Jun 20, 2011, 18:01:38

If you can establish that the set is producing noise, there's a greater chance of BT taking you seriously. Moving from IDNet wouldn't change the situation, btw, as this bit is down to Openreach.

tehidyman · Jun 21, 2011, 12:09:18

Having involved IDNet support it would appear that nothing can be done for this problem and if BT attend then I will get the bill in any case. Looks like a move to LLU is the only option. Fibre to cabinet not scheduled till March next year and as the problem is on the last 300m of copper I presume it will not make any difference.

Glenn · Jun 21, 2011, 12:17:44

The LLU will use the same 'last mile' cabling too.

tehidyman · Jun 21, 2011, 12:31:10

Quote from: Glenn on Jun 21, 2011, 12:17:44
The LLU will use the same 'last mile' cabling too.

Agreed but will escaping the BT DLM enable my connection to cope better? It seemed to before I moved to IDNet.

Rik · Jun 21, 2011, 12:42:31

AFAIK, LLU operators still use DLM, just not profiles.

tehidyman · Jun 21, 2011, 13:08:49

Quote from: Rik on Jun 21, 2011, 12:42:31
AFAIK, LLU operators still use DLM, just not profiles.

MisterW · Jun 21, 2011, 13:09:42

If you're on 21CN it IS possible to get BT to hard-set your profile which effectively stops the DLM messing things up, you just need to get your ISP to badger them.
For instance mine is currently

QuoteBT have managed to hard-set your profile and it's showing as active in the exchange already: WBC 160K - 24M No delay (INP 0) 6dB Downstream, 448 No delay (INP 0) 6dB Upstream (ADSL2+)

effectively means my target SNR up&down is fixed at 6db, excessive errors (or a drop in SNR) will still cause my line to resynch BUT it (the DLM) won't ramp up the target SNR (or apply interleaving) in an attempt to stabilise.

pctech · Jun 21, 2011, 13:17:06

That's interesting to note MisterW.

.Griff. · Jun 21, 2011, 14:17:55

Quote from: Rik on Jun 21, 2011, 12:42:31
AFAIK, LLU operators still use DLM, just not profiles.

Be don't.

They allow the customer to select their own SNR profile (3dB, 6dB or 9dB) and allow the customer to select Interleaved or Fastpath.

They will only intervene and impose a lower sync if there's a justified reason for doing so.

.Griff. · Jun 21, 2011, 14:28:27

Quote from: MisterW on Jun 21, 2011, 13:09:42
If you're on 21CN it IS possible to get BT to hard-set your profile which effectively stops the DLM messing things up, you just need to get your ISP to badger them.
For instance mine is currently effectively means my target SNR up&down is fixed at 6db, excessive errors (or a drop in SNR) will still cause my line to resynch BUT it (the DLM) won't ramp up the target SNR (or apply interleaving) in an attempt to stabilise.

MisterW where is that quote from? Someone at Idnet support?

I plan on calling them and asking about hard setting my profile so it would be useful to know who you spoke to.

.Griff. · Jun 21, 2011, 15:25:10

Forget the above.

I spoke to James and although it's possible to hard-set profiles on 21CN it's not possible on fibre connection. Damn..

pctech · Jun 21, 2011, 16:26:47

Quote from: MisterW on Jun 21, 2011, 13:09:42
If you're on 21CN it IS possible to get BT to hard-set your profile which effectively stops the DLM messing things up, you just need to get your ISP to badger them.
For instance mine is currently effectively means my target SNR up&down is fixed at 6db, excessive errors (or a drop in SNR) will still cause my line to resynch BUT it (the DLM) won't ramp up the target SNR (or apply interleaving) in an attempt to stabilise.

Do you know if this applies only to ADSL2+ or can it be applied to lines provisioned as ADSL Max but delivered over 21CN?

Rik · Jun 21, 2011, 16:42:14

AFAIK, Mitch, only true ADSL2+.

pctech · Jun 21, 2011, 17:05:55

Will have to talk to Zen.

Lance · Jun 21, 2011, 17:45:14

Just to be clear, is this hard setting the actual profile, or the SNR target?

Rik · Jun 21, 2011, 17:51:35

In my case, it was the SNR target and interleaving, Lance.

MisterW · Jun 21, 2011, 17:57:02

QuoteMisterW where is that quote from? Someone at Idnet support?

Nope, PlusNet support, I'm with them.

QuoteDo you know if this applies only to ADSL2+ or can it be applied to lines provisioned as ADSL Max but delivered over 21CN?

Not sure if its just ADSL2+, might be.

QuoteJust to be clear, is this hard setting the actual profile, or the SNR target?

Its hard setting the SNR target and the Interleaving depth.

pctech · Jun 21, 2011, 18:09:32

I wonder if that option is available to all BT Wholesale ISP customers or just BT Retail which Plusnet is a division of as we know how fair BT can be

No offence MsiterW.

Rik · Jun 21, 2011, 18:15:54

It was available on trial to IDNet, which is how my line got set. I haven't heard that it's been rolled out since, though.

pctech · Jun 21, 2011, 18:19:47

I do think that BT have their preferred customers (probably those that spend the most on circuits per month or of course, divisions of the mothership)

Rik · Jun 21, 2011, 18:23:30

I'm sure you're right, Mitch, but Ofcom don't seem to have noticed.