VDSL2 noise margin

guil

I'm with sky and had a problem with broadband recently, turned out to be a break in the wire at the junction box.

As part of the troubleshooting they dropped my profile down to 15mb and now they are saying that's all it can handle.

My attenuation is 21.7 and Snr is 14.6

Any idea on what speed I should be getting? I was with Vodafone for years previously and was on 30mb.

ED E

22dB would suggest about 1600m from the cab. 4dB to work with wouldnt get you from 15 to 30.

My guess would be you've another cabling issue on the path or the repair wasnt up to original standard. Unfortunately getting an issue like that fixed is near impossible. If the repair was recent wait a month then call again and the prequal test may let you back up to the 24Mb profile.

babi-hrse

Download snr needs to be 10.1 at a minimum it will work at 9.2 but it would be operating above max attainables which is to say it'll work but expect random disconnects when you really try to pull data. Your profile is way too low but that would look like it's an intermittent issue. On Monday that could have been the profile your line could only take then Tuesday the line improves and the snr rises to move it back up might result you getting disconnects when it's raining particularly hard. Other issues could be bridge taps. Where somebody has joined all the lines in the house together in series sending your line everwhere around the house picking up noise.
Best thing to do is to ask your provider to do a line test and see if there's any shorts, cross lines, imbalances a break on one leg will give broadband although it'll be really crap. After that was resolved it's up to your provider to bump it back up. There is something called dynamic line management which is supposed to automatically raise or lower your line after a few days whether it is on or not I wouldn't know.
Ring provider or if you know someone in openeir or kn who can change it.

guil

Funny thing about the attenuation is the engineer said I was 628 metres. We are direct to the exchange and about 850 metres by road.

I'm going to ask a friend a few doors away what their attenuation is.

ED E

I'm with sky and had a problem with broadband recently

You still have a fault. Attenuation can be artificially raised by things like filters in the wrong place but also by bad joints and the like. Or crap phone cables that people buy in Dealz. Trick will be convincing them to get a tech to look at it and getting lucky with the right tech.

guil

Checked the brother in laws, he is at the top of the estate and is 250 metres closer to the exchange. His attenuation is 18.6db and snr is 11.8

guil

ED E wrote: »

You still have a fault. Attenuation can be artificially raised by things like filters in the wrong place but also by bad joints and the like. Or crap phone cables that people buy in Dealz. Trick will be convincing them to get a tech to look at it and getting lucky with the right tech.

The tech was there for a good while and cluldnt find any fault at first. He was pulling at the wires at the junction box and said one of them was broke but hadn't come away altogether.

It has been solid since then whereas before it was really intermittent and would drop regularly.

Snr was as low as 5.4

guil

Forgot to add, the cable from the wall socket to the router is the new one sky supplied with the router. There's no other phone wire in the house and that one was newly installed January 2014.

guil

Neighbour 4 doors away with sky too has attenuation of 21.7 and snr is 7.8 at 25mb.

They increased mine to 25 and the snr is 8.1

babi-hrse

There's a joke about lines being miles away from an exchange being naturally bad because the longer it is the likelihood its gonna have a problem somewhere also that they are less well looked after as there are usually very few using them so far out due to lack of decent services. The other end of that is lines directly to the exchange are almost always equally as poor. Countless times I've encountered problems with a line only going next door to the exchange and it'd be riddled.
This may be due to things such as the oldest cables in the network or not air pressurised coming out from the exchange and far too many joints failing.