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2 miles from cabinet?

Chriz
Dabbler
Posts: 17
Registered: 06-11-2010

2 miles from cabinet?

I had an engineer out today who got 10Mb plus at my cabinet but couldn't synk at my house. I am around 9 mile from the Aghalee exchange in Northern Ireland and 2 mile by road from my cabinet. BT are sending out another engineer to check the joints in the line he says. Should this work OK at 2miles?
8 REPLIES
Community Veteran
Posts: 14,469
Registered: 30-07-2007

Re: 2 miles from cabinet?

10Mb at the cabinet is pretty bad for FTTC - it should be a fibre connection to the exchange which should easily manage 40Mbs over 7 miles.
Your long line is going to cause problems and seriously affect any FTTC speeds you could get. How much depends on the quality of the line.
Chriz
Dabbler
Posts: 17
Registered: 06-11-2010

Re: 2 miles from cabinet?

Well his reading said 10Mb to 40Mb, which doesn't sound very specific! Lol. It is fibre to the cabinet. Thank you for the info. Any ideas on how to move things along with BT? Is it possible that the line quality is so bad over 2 miles it won't work? I did have adsl before which worked intermittently. I've been waiting on fttc for ages in the hope it would work. Apparently I'm the first fttc customer on my cabinet.
Hope it works!!!
Community Veteran
Posts: 1,699
Registered: 30-07-2007

Re: 2 miles from cabinet?

Did he mean 40Mbs download and 10Mbs upload?
ashgeo
Grafter
Posts: 93
Registered: 24-07-2008

Re: 2 miles from cabinet?

Chriz

From: http://en.wikipedia.org/wiki/Very_high_speed_digital_subscriber_line_2

"VDSL2 deteriorates quickly from a theoretical maximum of 250 Mbit/s at source to 100 Mbit/s at 0.5 km (1,600 ft) and 50 Mbit/s at 1 km (3,300 ft), but degrades at a much slower rate from there, and still outperforms VDSL. Starting from 1.6 km (1 mi) its performance is equal to ADSL2+".
[Note BT currently cap it at a maximum 40meg but potentalially it has a speed of 100meg (I've read this somewhere!!)].
ADSL2+ Sync rates are reported to be around:
Less than 1km should be 23-24Mbit
1.0km = 13.81dB = 23Mbit
1.5km = 20.7dB = 21Mbit
2.0km = 27.6dB = 18Mbit
2.5km = 34.5dB = 13Mbit
3.0km = 41.4dB = 8Mbit
3.5km = 48.3dB = 6Mbit
4.0km = 56dB = 4Mbit
4.5km = 62.1dB = 3Mbit
5.0km = 69dB = 2Mbit
So in theory you should be able to get around 4meg depending on the quality of your phone line and local interference. I Get a steady(ish) 1meg on an ADSL2+ line that is around 7-8km long with a downstream attenuation 74.5dB.....
Good luck!
George
itsme
Grafter
Posts: 5,924
Thanks: 1
Registered: 07-04-2007

Re: 2 miles from cabinet?

I read 'Starting from 1.6 km (1 mi) its performance is equal to ADSL2+' to mean that at 1.6km the speed will be 20Mbit, so at 2 miles (3.2km) I would say the speed will be between 6 and 8 Mbit
Chriz
Dabbler
Posts: 17
Registered: 06-11-2010

Re: 2 miles from cabinet?

Wow, amazing guys thanks for all the info!
Another Bt engineer was out today who tested the line and said there are no faults and that it is a 4.2km line from the cabinet. They said on the form that was left (I was out) that my line seems to be outside the working limits for BT infinity. And he told be to contact Bt infinity helpdesk! He didn't realise he was working for Plusnet as the ISP I guess. Surely distance isn't the only problem, line quality or a bad joint - should BT fix this? ~7 mile of fibre installed, and the last 2.5mile of wire let's it down. Doesn't make sense especially because adsl from the exchange could sync before (allthough temperamental)?
prichardson
Grafter
Posts: 1,503
Registered: 05-04-2007

Re: 2 miles from cabinet?

In a Local Network (LN) engineer has been out and confirmed the line distance, it does sounds like your line is not going to be capable of FTTC.
Would be interested to know more about how the original engineer tested speed. He should have been attaching a JDSU (line testing) unit, which will operate in FTTC direct (built in modem) and give a highly accurate upstream and downstream figure. No vague responses from this little piece of very high end kit.
I do suspect what may have already been said in that is stated 40Mbps down and 10Mbps up at the cab. Testing at the cab means there is no additional cable being measured and any incorrect figured hear mean there is a problem with the VDSL kit in the cab, not the line.
Ashgeo.
FTTC services are restricted in the UK under the (ANFP) Access Network Frequency Plan to specific frequencies. The maximum at this is 40mbps. In line with this, the theoretical maximum.
If you want some long boring reading, you can read up about out the ANFP - http://www.niccstandards.org.uk/ - Good luck with that though Wink
Specifically publication ND1602
Chriz
Dabbler
Posts: 17
Registered: 06-11-2010

Re: 2 miles from cabinet?

The measurement at the cabinet I was told, was given 10Mb to 40Mb range, defo. I don't know what he used for that. But at the main socket in my house he used a handheld tester, like a big visa card machine :-). This wouldn't sync up with the line.
It wouldn't have anything to do with my ip profile, I don't actually have adsl or anything at the mo. I was REALLY hoping fttc would work!