Failed fibre installation - 80A RF2 filter found

Hi,
For years we've had ADSL running at 1.6Mbps and given up on ever getting any faster over ADSL. Recently we got mailed by BT about Infinity now being available so I got in touch with our ISP (Utility Warehouse) and arranged to switch to their Ultra Broadband fibre service.
The engineer turned up today and the switch over failed because the Openreach modem couldn't sync, so we are back on ADSL.
After the engineer left I went up into the loft to see if the wiring from the point of entry to the master socket was easily accessible in case there was damage there or anything. After removing some loft insulation I found the cable and an 80A RF2 filter. Never seen one before but the Internet revealed that you shouldn't have one of these on an ADSL line. As it's on the BT side of the master socket I left well alone but could this be responsible for my slow ADSL performance?

The whole reason for moving to fibre was that I couldn't see any other way of getting a faster Internet connection but now I've found the RF2 I'm thinking that maybe if that was changed to an RF3 we could stay on ADSL and get a usable speed without the extra expense of a fibre service.

Also, would the RF2 stop the Openreach fibre modem syncing? My ISP are claiming it wouldn't and that the engineer found an exchange fault after he left my house. They say he's rectified that fault but surely he would have come back and finished the job?

I want to get the RF2 changed and cancel the fibre service assuming we get a decent speed increase. I'd be happy with 5Mbps to be honest - just enough to be able to use iPlayer etc. without buffering which is a bit hit and miss at the moment.

What do you wise chaps think?

Mark.

What are the current ADSL stats from the router?

An RF2 will impact on the ADSL and VDSL2 speeds, an RF3 should be fitted for DSL services. Or if the RF2 was put in years ago it is possible the noise interfering with the voice service has now gone and no noise filter is needed.

Hi MrSaffron,
Stats as requested:

Uptime: 0 days, 3:14:18
Modulation: G.992.3 Annex A
Bandwidth (Up/Down) [kbps/kbps]: 793 /3,048
Data Transferred (Sent/Received) [KB/KB]: 0.00 / 0.00
Output Power (Up/Down) [dBm]: 12.5 / 0.0
Line Attenuation (Up/Down) [dB]: 28.5 / 54.0
SN Margin (Up/Down) [dB]: 7.0 / 6.5
Vendor ID (Local/Remote): TMMB / µ
Loss of Framing (Local/Remote): 16 / 0
Loss of Signal (Local/Remote): 4 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 36 / 0
FEC Errors (Up/Down): 13 / 40,714
CRC Errors (Up/Down): 1 / 28
HEC Errors (Up/Down): 1 / 20

Thanks,
Mark.

In reply to a post by daccordimark:

Bandwidth (Up/Down) [kbps/kbps]: 793 /3,048
...
Line Attenuation (Up/Down) [dB]: 28.5 / 54.0

Those figures aren't that far out of whack. How far from your exchange are you? I suppose the filter could increase attenuation. If you're about 4km from your exchange then your're about at the maximum for ADSL.

Edited by Andrue (Fri 07-Mar-14 21:50:20)

A photo of the inside of the BT80 will help people diagnose if it is a BT80 or BT80RF.

In reply to a post by daccordimark:

Bandwidth (Up/Down) [kbps/kbps]: 793 /3,048

On that connection speed you should be getting between 2.2 and 2.5Mbps real throughput speed, not the 1.6Mbps you give in your OP. Do you connect wired or wirelessly to your router?

If it really is an RF2 then it will have the effect of increasing the attenuation significantly and should either be replaced or removed from the line entirely

I'm going by the markings on the back and the fact it matches this one:

http://www.run-it-direct.co.uk/BT80ARF2.html with two visible inductors rather than the single visible one on the RF3.

When I spoke to UW technical support yesterday they, in their words, "forced some more speed down the line" so I now get 2.6Mbps on the thinkbroadband speed test. http://www.thinkbroadband.com/speedtest/results.html...

The stats I posted were after they had done that. We've had those kind of speeds before but it's never lasted.

I'm slightly confused now because it seems as if an RF2 doesn't always mess up the ADSL speed from what some of you had said and that we are now running at the maximum we could expect. Also, does anyone know if it would definitely stop the fibre from working?

Thanks again,
Mark.

As you can see it's stopping ADSL2+ from working, so chances are, yes.

A reasonable provider should when told an RF2 is connected to a line know that it should be swapped over to an RF3

You need to get onto the broadband provider to get this swapped out. Since your line is possibly long, thus only using the lower frequencies the RF2 effect may be less on ADSL2+, but the effect on VDSL which wants to use a lot more frequencies could be a lot larger.

If after a week of trying you get nowhere, then email me [email protected] with a link to this thread and the line details and I'll see if something can be done by going direct to Openreach

In reply to a post by daccordimark:

I'm slightly confused now because it seems as if an RF2 doesn't always mess up the ADSL speed from what some of you had said and that we are now running at the maximum we could expect.

To try and clarify. For that downstream attenuation your connection speed is close to the maximum.

However:
* The throughput you are getting is lower than you should for that connection speed.
* The filter might be artificially increasing the attenuation on your line.

It would help if you could estimate the distance from your telephone exchange. The cable won't go in a straight line but if you assume it takes the obvious road route that should give you an idea. 54db attenuation equates to approximately 4km of typical cable.

Mark,

Regarding "forcing more speeda down the line" you can force ANY information rate you like down a bandwidth (in Hz!) PROVIDED you have lots of spare S/N to trade off.. I think usually there is an assumption that S/N at (? 300kHz) will define total performance which isn't the case if your RF2 is slicing off higher frequencies.

Secondly the RF2 was put there for a reason - does it still exist ? suggest ask neighbors if they had trouble. If whatever it was is history OK but if you live in Droitwich say with 400 kW on 198 kHz you will still need something and I suspect the RF2 may be better than RF3

Hi Guys,
Following the obvious road route it is 1.1km from the exchange to the cabinet and then 0.5km to our house. As for possible RFI problems we have line of sight to this: http://en.wikipedia.org/wiki/Moorside_Edge_transmitt... 1.5km away.

Cheers,
Mark.

The thing is, and here's the thing, if it is an RF2 filter, chances are it would be killing the ADSL stone dead.

I wonder if the OP could ask what speeds, on ADSL, his neighbours are getting ?

I'd also be asking for his ISP to arrange a revisit for the installation of the VDSL, get a halfway decent engineer out there, show him what you think the issue is, and have them sort it.

If the line is in the 1.5 to 2km range then the RF2 is killing off your ADSL speeds already

As suggested need to return to the ISP with the new information and get the info passed down the change for an engineer install

Does http://windows.mouselike.org/be/index.asp?DoAction=B... give the line length?

With three transmitters around 1MHz pushing out 400kW just 1.5km from the house there are going to be some real problems. Will and RF2 or RF3 actually solve them? or just limit the capability?

Would allowing an FTTC install without a filter get reasonable results but with a big notch of missing frequencies from 950 to 1250 kHz?

Edited by MHC (Sun 09-Mar-14 10:27:33)

"Would allowing an FTTC install without a filter get reasonable results but with a big notch of missing frequencies from 950 to 1250 kHz? "

At the sort of power level involved the modem could go into overload and loose many channels. If it stays in control it could de-sensitise just those channels BUT I would be surprised if the RF didn't enter by several routes - power supply, phone extensions and/or ethernet link to computer.( Are power lines overhead ? ) With several paths you can get complications due to phase differences - i.e. two 1 mV levels of interference can add up to anything from 0 to 2 so removing one can seem to make things worse - so one step at a time !

As the RF2 is already rejecting in-band interference adequately (?) I would be half inclined to see what happens to ADSL by substituting a RF3, since a RF4 (or whatever for VDSL) is two stages worse for CM rejection of 500kHz or so., but I'm not a speed demon !

P.S. Just calculated 100kW @ 1.5km gives about 1 volt/metre The RF2 is doing a good job. !

Edited by deleted (Mon 10-Mar-14 09:51:51)

Just like to add that I had an ADSL2/2+ connection back in 2007 with an attenuation of 58-60db and was getting 6-8mb at 6db snr

Edited by Seansmit17 (Mon 10-Mar-14 16:37:24)

58-50? Should that be 48-50?

58-60, fixed

Mark

Thinking about it, suggest you need a monitoring program which looks at ADSL channels, not just total information rate, .like DSL Stats
If as I suspect the RF2 is cutting off above 300-500 kHz then if it was replaced by a device cutting 850 - 1300 kHz this would improve ADSL1 let alone 2 or VDSL. Getting anything changed for an unusual situation will be a lot of work, so good idea to be sure of the facts.

Latest info today (Wednesday) from Utility Warehouse is that Openreach are working on fixing the cabling fault in the cabinet and will update in 1 or 2 days. Mind you they said that on Monday too. I can't get a straight answer out of UW as to whether Openreach know or care about the RF2.

My worry is that Openreach are wasting their time.

Thanks for everyone's input so far.
Mark.

Not unheard of for there to be Port/ wiring faults In the cabinets.

Had an unannounced visit from Openreach yesterday and the engineer knew nothing about the RF2 filter so that message hadn't got through from my ISP. He hadn't found anything wrong outside the house and agreed with me that the RF2 was the cause of my problems. He very kindly removed it and reckoned other people in the area hadn't suffered any problems after having theirs removed. I now have the following stats (previous figures in brackets).

Uptime: 0 days, 12:47:56 (0 days, 3:14:18)
Modulation: G.992.5 Annex A (G.992.3 Annex A)
Bandwidth (Up/Down) [kbps/kbps]: 1,020 / 8,189 (793 /3,048)
Data Transferred (Sent/Received) [KB/KB]: 0.00 / 0.00 (0.00 / 0.00)
Output Power (Up/Down) [dBm]: 12.5 / 0.0 (12.5 / 0.0)
Line Attenuation (Up/Down) [dB]: 14.0 / 28.5 (28.5 / 54.0)
SN Margin (Up/Down) [dB]: 10.0 / 6.5 (7.0 / 6.5)
Vendor ID (Local/Remote): TMMB / µ (TMMB / µ)
Loss of Framing (Local/Remote): 24 / 0 (16 / 0)
Loss of Signal (Local/Remote): 6 / 0 (4 / 0)
Loss of Power (Local/Remote): 0 / 0 (0 / 0)
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 4,075 / 0 (36 / 0)
FEC Errors (Up/Down): 0 / 18,386 (13 / 40,714)
CRC Errors (Up/Down): 0 / 7 (1 / 28)
HEC Errors (Up/Down): 0 / 7 (1 / 20)

The TBB speed test is giving us just under 7Mbps.

http://www.thinkbroadband.com/speedtest/button/13951...

Do those stats look OK because at the moment I'm more than happy with my connection speed. We can stream iPlayer in HD which is about as heavy as usage will get in our household. We don't download huge amounts of stuff or have lots of simultaneous users so I'm going to cancel the fibre upgrade completely.

That is good news !
It seems you got an "Engineer" - "an ingenious solver of problems" not a time server. Your attitude to speed is like mine- if it does what we want that is OK - don't pay for what you don't need.

I wonder if the RF2 is a relic of open wire overhead wires now replaced with underground ?

Excellent stats.

However, you are on an LLU service capped at 8Mbps. I haven't got access to an attenuation/speed graph at the moment, but gut feel is it would be about double that if uncapped.

That might be more expensive from UW and unnecessary for you at the moment if it is. The potential is there .

Thanks for the replies guys.

I've found out there did indeed used to be overhead BT cables to the house but not in the six years we've been here. The OR engineer mentioned we were on an underground feed all the way.

He also said the line was able to run even faster - 10Mbps I think - but 6.9 will do us fine.

It's great to have forums like this with experts on hand to sanity check theories and give the uneducated end-user some confidence in dealing with ISPs etc.

Cheers,
Mark.