VDSL vs ADSL

[SimonEasty]

Hi,

For the last few years we have been on VDSL (FTTC). It has been fine but speeds have been slower than they were on ADSL. Would it be worth moving back to ADSL2, given all neighbours are on VDSL? To reduce crosstalk etc.

I also know that the neighbour opposite gets speeds of ~10 Mbps down.

We are roughly 2.6km from the cabinet (using daftlogic and tracking the phone line poles). We currently have a smarthub 2 which according to another post might not be optimised for ADSL at long distances. Is there a distance at which VDSL becomes worse than ADSL?

I have attached my broadband availability checker data, and the technical log from the hub manager.

[licquorice]

A few things.

Yes, there is a crossover point where ADSL may be faster than DSL

I don't think that is the case for your line

You have a high noise margin and thus lower than optimum speed probably due to a line fault,  but possibly due to you attempting to increase your speed by frequently rebooting the hub.

Is there any noise on your line with a quiet line test 17070?

[SimonEasty]

The noise margin has stayed around 11dB for quite some time. I've only rebooted the hub a few times in the last two days.

I tried the 17070 quiet line test this morning. It was very quiet. On speaker there was no hissing, but to the ear there was a slight hissing. Again I have no idea what is deemed good/bad so very difficult to tell.

We have had issues in the past where there is feedback/echo on the landline. Very audible, but only happens occasionally (say 1 in 4 times).

[licquorice]

On a corded phone, 17070 should be totally silent

[SimonEasty]

It's a wireless phone. Would it be worth trying the test socket? Or is that likely to be worse as I'd be using an old ADSL filter (of unknown quality) on a VDSL line?

And if I do that, how long does it take for DLM to kick-in?

[rbz5416]

As long as there's no pops or crackles on the line you should be good, but try again when you next experience the echo.

You can also run landline tests from the Help section of MyBT.

Have you tried plugging the router directly into the test socket behind the master socket faceplate to rule out internal wiring?

[licquorice]

Pops and crackles are usually a symptom of high resistance or corrosion type faults. Earth or battery contact faults due to poor insulation and wet joints can manifest themselves as hum or hissing.

[SimonEasty]

Plugged it into the test socket using an ADSL filter. Noise margin down to 10.7dB. Line attenuation down to 36.9dB. Speeds (data rates) are identical.

I'm guessing it has to stay in this configuration for a day or so to normalise? Also what should be a "good" noise margin give my ~2.6km distance from the cabinet?

[licquorice]

Noise margin is not dependent on distance, under normal circumstances it should be 6dB or for some cabinets 3dB.

It might be worth calling CS on 0330 1234 150 and request a DLM reset

[SimonEasty]

They said only an engineer can do a DLM reset. So I've got one booked for next week.