Very slow FTTC

Hi, I've just moved to vdsl in the last week, and while I *know* the cabinet is still a mile away I had been hoping to improve upon my reasonable 4Mb ADSL

With the ECI modem the speed is 4.5Mb/0.6Mb (adsl was 4Mb/0.9Mb)

Sadly the ECI gives no details so I've changed to the HG612 for testing (which is connected at a terrible 2.5Mb/0.5Mb)

Anyone able to help interpret this graph?

http://i.imgur.com/jbchU.png

What was your estimate?

Estimate was 10.9/1.0

So you are a distance from the cab, the only option for you is to contact BT.

According to the VDSL Band Status you only have 1 upstream and 1 downstream band.

At that distance I am surprised they accepted the install. As you are well down on estimate and sub 5Mb then you need to speak with your ISP and, if you want to, ask to be returned to ADSL at the lower cost.

That said, I have to ask where your modem was connected when you did the measurements? In the test socket? on a long extension? and how much internal wiring do you have from where it comes through the wall to the master? Can it be shortened?

I can tell you what I see is interesting.

Is that if BT sold adsl2 from cabinets that would help people in your position.

The attenuation on D1 is 30db. For adsl if you had 30db attenuation you would have a much improved signal over your old adsl. But from cabinets vdsl2 is the only service offered by BT. The problem with the VDSL2 service however is to protect existing adsl services the frequencies that conflict with adsl have the power cut back, and it seems your conneciton cant make use of the frequencies above those hence the poor sync speed.

This power cutback to protect adsl has probably lost you 2/3 to 4/5 of the signal you would otherwise have. Ultimately there is nothing you can do about this as openreach dont provide adsl from cabinets and the vdsl2 policy is there for good reason to protect existing adsl services. I think you would be around 10-12mbit sync if on a adsl from the cabinet service.

Edited by Chrysalis (Tue 08-Jan-13 03:43:40)

Surely, though, ADSL from a cabinet would have to have a power mask just as tough as the VDSL2 power mask applied in order to prevent crosstalk from trashing ADSL from the exchange and other VDSL2 connections. In that case, offering ADSL from the cabinet is of very little advantage. Further, ADSL from the cabinet would lessen the effectiveness of vectoring VDSL2 for reducing crosstalk.

The only way round this would be to require all DSL in areas with FTTx cabinet to be provided from the cabinet - but that would preclude DSL via LLU and SLU, which Ofcom are not going to allow.

yes it adds complexities in various ways hence its a no go and isnt future proof at all as vdsl2 replaces it.

I was just saying what could have worked well for long lines from cabinets.

Modem is connected to a 7m cat5e extension, which is connected to the punch down socket behind the front plate.

There is no extension wiring and it is no better/worse when plugged directly into the nte.