Does this fibre line look ok?

It just got activated today. This is pasted from my sky hub sr102 black one.

Connection Speed 39718 kbps 9999 kbps
Line Attenuation 22.3 dB 0.0 dB
Noise Margin 6.6 dB 6.6 dB

I don't know why my upstream line attenuation is 0.0db. Should i be worried about that?
I'm on the 40/10 package

cheers for any thoughts or advice.

Upstream attenuation is often shown as 0.0 - nothing to worry about. Somewhere in the information exchange between DSLAM and modem the detail is passed and in the case of some modems, not dealt with correctly.


Based on your figures, I would suggest that the max attainable will be around 40.5-41.0 down and 10.5-11.0 up. So, don't even think about looking at any other options.

The 0.0dB is just a UI bug

I'd usually expect around 39 to 60 Mbps at 22dB attenuation and 7.8 to 12 Mbps upload.

No point in upgrading for more download speed usually unless the downstream speed is nailed to the maximum.

So for the 40mb package it looks like my line is stable and running ok then?
Thats what i want most, A nice stable connection that never drops out or changes speed.

Cannot comment on stability from just one set of figures, i.e. only way to know is to see how it performs over time.

Has your cabinet been live for a fair while, or only recently and you are an early adopter?

It went live late Jan or early Feb this year so not that long.
Sorry for slow reply

Looks fairly good but not excellent. As more join the cabinet you may lose a bit of speed from crosstalk, but it should stay stable apart from that.

Throughput consistency depends on your ISP of course. I hope it goes well for you.

It has reconnected once so far, i might be in line training? Do Sky do that with fibre?

This is my speedtest results from this site.

10-03-2016 22:05:53 (GMT) 36.7 Mbps 9.3 Mbps Sky
10-03-2016 22:04:07 (GMT) 36.8 Mbps 9.3 Mbps Sky
10-03-2016 22:03:45 (GMT) 37.0 Mbps 9.4 Mbps Sky
10-03-2016 20:41:31 (GMT) 36.5 Mbps 9.2 Mbps Sky
10-03-2016 20:41:05 (GMT) 36.5 Mbps 9.2 Mbps Sky
10-03-2016 18:25:48 (GMT) 36.8 Mbps 9.1 Mbps Sky
10-03-2016 18:25:12 (GMT) 36.9 Mbps 9.1 Mbps Sky
10-03-2016 18:24:32 (GMT) 37.0 Mbps 9.5 Mbps Sky
09-03-2016 15:06:10 (GMT) 37.1 Mbps 9.2 Mbps Sky

Last result at top was just now as was 3rd from top 37.0. It seems to be staying stable overall in speed to me since activation yesterday. Ping is also staying around the 9-10ms mark to google.co.uk

Line training as such doesn't exist on FTTC, and anything similar that does is the province of the Openreach DLM.

That runs from the minute you first connect. If your line is seriously unstable it will take serious action during the day of first connection and the end of the first full day.

If there is a highish number of errors expect it to do the normal sort of intervention some time tonight, such as turning interleaving or G.INP on.

In reply to a post by MrSaffron:

The 0.0dB is just a UI bug

I'd usually expect around 39 to 60 Mbps at 22dB attenuation and 7.8 to 12 Mbps upload.

No point in upgrading for more download speed usually unless the downstream speed is nailed to the maximum.

Hmm, what attenuation do you need for 74Mbps? Somebody I know with 21.1 attenuation gets 19999/79995.

Does 1dB really whack such a huge chunk off it? As I currently have 23.2dB.

Edited by Danh_Gbwe (Fri 11-Mar-16 00:57:24)

It has reconnected again. Now its stats are.

Connection Speed 39050 kbps 9999 kbps
Line Attenuation 22.3 dB 0.0 dB
Noise Margin 6.8 dB 6.6 dB

ping seems the same. 10ms to google

How do i tell with a Sky sr102 if it's changed to g.inp?

In reply to a post by Danh_Gbwe:

In reply to a post by MrSaffron:

The 0.0dB is just a UI bug

I'd usually expect around 39 to 60 Mbps at 22dB attenuation and 7.8 to 12 Mbps upload.

No point in upgrading for more download speed usually unless the downstream speed is nailed to the maximum.

Hmm, what attenuation do you need for 74Mbps? Somebody I know with 21.1 attenuation gets 19999/79995.

Does 1dB really whack such a huge chunk off it? As I currently have 23.2dB.

It is not just attenuation that defines the achievable data rate, noise levels play a significant part too. An extra dB of noise may have a similar effect to an extra dB of attenuation. I have seen 16dB attenuation give syncs at 78 down to about 72.

In answer to your question though: around 14 to 18 dB would be the level where speeds around 74Mbps could be achieved.

Connection Speed 36865 kbps 9999 kbps
Line Attenuation 22.2 dB 0.0 dB
Noise Margin 6.4 dB 6.6 dB

It has slowed today and it seems to be reconnecting almost twice a day. Doesn't look good for me does it.
What does anyone think is going wrong and what shall i say to Sky? or shall i leave it for a while and see if it settles down?

So, what is causing the disconnects?

Router Stats Lite should work with the SR102 but I am not sure if it works with VDSL lines ... Try it and see. Monitor the SNR and see what happens.

I got a error with a windows 8.1 laptop with router stats light. Can you give me a link to router stats light to make sure i was on the correct site.
Other news i have talked to Sky and they think there might be a fault with my line but wouldn't say what. There phoning back at 1pm to talk about a engineer being sent out. I asked if i would be charged if it turned out to be the equipment or cables in my house and Sky adviser said no, is this true?
The master socket is so old it does not have a test port if i open it up. So i am worried it is that.

I always had minor issues with my normal dsl but i put up with it and it didn't disconnect twice a day. Just ran slower and could vastly change speed (upto 3mbit difference depending what time of day/week i rebooted router)

Edit: and our landline voice calls has always been lower quality than all mobiles even with different landline phones tested. Think it really is about time i got this looked into.

Edited by deleted (Fri 11-Mar-16 11:37:21)

Does the master socket have three connectors in use? If so they will be on terminals 2, 3 and 5.

Carefully detach any on Terminal 3. It is no longer needed and is a major source of noise..

RouterStats Lite should be obtained from http://www.vwlowen.co.uk/internet/files.htm . He is the author.

Thanks for the help. I don't think router stats works with the SR102.
I already removed the extra terminal cables unless what you're saying is different from the ringwire removal i did years ago.

I might have to hope Sky can fix it

T3 is the ringwire, yes .

Here: http://www.vwlowen.co.uk/internet/files.htm#routerst...


The Sky adviser is WRONG. Anything past the master socket (whatever type) is your responsibility ... Although if the device is faulty you may have a case.. Do not commit to it unless they confirm their statement in writing.

It has reconnected again even now and this time it has changed even more differently

Connection Speed 37072 kbps 9977 kbps
Line Attenuation 22.3 dB 0.0 dB
Noise Margin 6.6 dB 5.5 dB

notice for first time upload has also slowed although download has got faster. Worse my ping was 9-10ms to9 google uk now its 20ms so somekind of fibre interleaving has been enabled now?

Router Stats LITE scroll down the page and it does have the SR102 on the list. http://www.vwlowen.co.uk/internet/files.htm#routerst...

That does sound like high error rates and noise bursts causing disconnections, and the latency jump does suggest interleaving has been applied. The first step is usually to add 8ms, but yours may be 12ms added. Interleaving normally knocks several Mbps off the downstream as well though.

VDSL2 is more susceptible to noise than ADSLx was for a variety of reasons.

One thing that should happen if an engineer comes would be the replacement of your master socket and the addition of a VDSL2 filter plate. With luck that would eliminate charging risk but may be free within the overall charge that might be applied.

With an engineer install of the FTTC it would have definitely been free.

As you've previously removed the ring wire, but have always had dodgy stability, I assume you have done all the standard checks, got filters on all used sockets, don't have the modem/router sitting on top of a PVR or similar and so on? I list quite a few problem areas on some of the pages in this section.

Edited by RobertoS (Fri 11-Mar-16 13:09:31)

I got a engineer visit scheduled for Tuesday. Another Sky support agent assured me it would not cost anything no matter where the fault is?
I will definitely take your advice on a new master socket. It is basically a given that one is needed, my current one is so old. Also ask about the vdsl2 filter plate.

I have done all the checks and over the years used many isps, routers, filters and on and on.
The biggest change was when i removed the ringwire with aaisp adsl max. My speed jumped from 4.5mbit to 6.5-7mbit. Then sometime later i moved to Sky due to there price and unlimited downloads LLU while maintaining BT line rental and it increased again, this time to 9.4 to 10.2mbit.

During all these years my line did drop out every so often on adsl and adsl LLU but not daily also interleaving seemed to be on most of the time.

Feb this year my line got worse i had to move my line rental and voice line to Sky from BT to get Sky Fibre when i did that the day they changed it my sync to Sky's own LLU dropped from 9.8mbit or so all the way down to 7.4mbit with heavy interleaving.
That is how it remained until Sky Fibre was installed on Wednesday this week which the above posts tells

I'll hope the engineer can finally find the semi minor issue this line has had for years and years and fix it for good..

I'm going to reset my Sky hub sr102. It has not been reset since the day i got it. See if that helps.

erg it disconnected again, i think this is 3rd time today.

Connection Speed 35779 kbps 10000 kbps
Line Attenuation 22.3 dB 0.0 dB
Noise Margin 6.6 dB 6.6 dB

fastest upload I've had slowest download since fibre.

I get 53 Mbps on a line with 15.5dB attenuation but about 40% of the line is 40 year old aluminium cable.

Sky are still saying there is a fault but not what it is. It's reconnecting is worse than i thought. It rarely makes it past 5 hours before reconnecting. Engineer still scheduled for Tuesday. Latest stats.

Connection Speed 36969 kbps 9827 kbps
Line Attenuation 22.2 dB 0.0 dB
Noise Margin 6.3 dB 5.5 dB

I really must have a fault. It reconnects so much. It last reconnected about 6 hours ago at this.

Connection Speed 37124 kbps 9842 kbps
Line Attenuation 22.3 dB 0.0 dB
Noise Margin 6.3 dB 5.5 dB

The speed never goes lower than 36mbit tho and if it does next time it reconnects it jumps to 37 or 38.
I have also noticed upload stays around 8900 to 10000kbit every time.

I don't know for sure if it is fixed or not but Openreach have been around and basically rewired entire internal phone wiring and installed a vdsl faceplate.

My stats have changed from the above to this

Connection Speed 39973 kbps 9999 kbps
Line Attenuation 21.8 dB 0.0 dB
Noise Margin 12.6 dB 8.8 dB

note line attenuation has dropped a little bit and noise margin has increased by quite a bit.

Does this seem better and like my line will hold near 40meg now?
the Openreach engineer said my line might just be too long to cab to stay at 39 and may still drop over next 10 days.

Cheers for any thoughts.

Edit the openreach engineer said there is 10 day line training on fibre (which he called infinity even tho i'm with Sky) Sky said to me there was no dlm (digital line management) or line training on there fibre. Who is correct?

Edited by deleted (Tue 15-Mar-16 13:46:02)

0.5 dB on change in attenuation is nothing much. Could be down to several things - shorter wiring length, an improved termination, a difference in matching impedance ...

6dB improvement in SNR suggests a noise source has been removed - maybe the rewiring took out a tuned circuit/antenna that was picking up radio transmissions which would kill certain tones.

We did find a 2nd cable from where phoneline comes into house from outside going into loft that came back down in a bedroom where no socket is anymore so lead no where. That was removed and all the wiring like i said is new so I'm hoping it will be ok.

Does anyone know if Fibre has 10 day line training like the engineer said or does it not like Sky said?
He told me to expect disconnections with line training for next 10 days.

The 10 day period is a myth. DLM works the same on day 1 as it is on day 500.

In reply to a post by blackmesa8:

We did find a 2nd cable from where phoneline comes into house from outside going into loft that came back down in a bedroom where no socket is anymore so lead no where.

That's been your problem with ADSLx as well. Star wiring before the master.

In reply to a post by RobertoS:

In reply to a post by blackmesa8:

We did find a 2nd cable from where phoneline comes into house from outside going into loft that came back down in a bedroom where no socket is anymore so lead no where.

That's been your problem with ADSLx as well. Star wiring before the master.

Thanks lee111s for that info and RobertoS. I am really hoping that finally i will have a internet connection i can call reliable. The stats on router are holding strong and the same as i posted earlier, normally my noise margin changes by up to 1db every few hours it is not anymore instead its staying solid at 12.6.

I will update over next few days if anything bad or interesting happens.

In reply to a post by blackmesa8:

Does this seem better and like my line will hold near 40meg now?
the Openreach engineer said my line might just be too long to cab to stay at 39 and may still drop over next 10 days.

My rough rule of thumb is that, for lines with speeds around 40Mbps, an extra 3dB of noise margin is worth around 8Mbps of speed downstream. You might be able to get speeds of around 55Mbps.