Sky router stats (speed, noise, attenuation) explained

[richypat07]

Thanks, but would bt replace it if it were faulty??
Cheers

[Saturday]

If they had to, yes, but bear in mind they only have to provide you with a line fit for voice calls. Can you make/receive voice calls?

[richypat07]

I received the following email a few days ago........
Thank you for contacting Sky Broadband Technical Support.
I have looked into this for you and have done a few things on the line, your line can hold 4mb which we are providing to yourself. Your distance from the exchange is 3.6km, can i ask you keep an eye on your connection over the next 24hrs if there is any issues please call or reply to this email.
My line stats have changed for the better (i think)

ADSL Link Downstream Upstream
Connection Speed 4096 kbps 768 kbps
Line Attenuation 15.5 db 31.5 db
Noise Margin 7.6 db 11.0 db

Do you think my line can now hold a faster speed?? Do I need to get them to retest my line etc??
All thoughts appreciated
Richy

[IWasNotTheEnemy]

in its current state, id say not a lot more is available...

reboot (as the attenuation 15.5 is a known bug) and post full router stats in a new thread in this forum and others can comment fully...

[skytsat1]

mayb in theory, but anything over 2Km will not handle 16Mb over 2.5Km doin well if they get 8 an there is no such thing as 65 att,(ok there is but it wont regester with th dslam any higher than 63) if ur sittin at 63 att ur lucky to be gettin bb, its almost always intermitent. u will have to do some line fidling before u can get anywhere near then figures u been giving.

[Saturday]

The figures are taken from published figures and "based on actual reported data from users" to quote the source. They have proven to be remarkably accurate to SkyBB customers who have a relatively quiet line.

There are many Sky BB customers enjoying higher than 8meg with a line length of over 2.5km (attenuation ~35db), myself included. My line is not especially good either.

A fair few Skyuser members report their attenuation as 63.5db. Yes the forum is full of advice and posts concerning the problems with high attenuation lines.

[Christof]

Hi there,
I'm new to Sky BB today and hence new to this forum... but very impressed by the willingness to help and the technical know-how available.

Can I just check a couple of things regarding my setup.... I have the feeling that I shouldn't complain about the performance I'm getting but would just like to check...

My Sagem router stats NOW show:
ADSL Link Downstream Upstream
Connection Speed 10176 kbps 764 kbps
Line Attenuation 38.5 db 20.6 db
Noise Margin 7.1 db 13.0 db

I use the word 'NOW' because I earlier was only getting about 7500 kbps downstream (didn't think to note the Attenuation). So I followed the recommendations of a few other posts and removed the wiring from pin 3 in what I have as my master socket. I also remembered another phone extension upstairs which I hadn't plugged through a filter.
So... Having removed the pin 3 wiring and rebooted the router I was up to about 9000kbps... plug the other extension in via a filter and I'm up to the 10176kbps you see above.

Reading this thread's excellent summary of the relevance of the stats I see that with an attenuation of 38.5db I shouldn't really expect much more than this (you quote 40db as 11800mbps potential. So I'm not far off that...

At one point in my playing about I did get the router stat show a speed of 11200mbps but I can't remember what combination of things I was doing at the time :-(

Anyway.. the real nub comes in trying to reduce my attenuation level, yes??

I have really old copper into my house that is actually connected through some ancient looking cast iron box outside... this then comes indoors to a 'master socket' which does have a few electronic components in (capacitor looking things) but doesn't really look like the things described as a 'decent' socket.

Do I assume correctly that if I clean all joint connection (maybe even solder the rubbish outside house)... also replace the master socket and maybe even replace some other internal wiring... I assume this will all reduce the total resistance/impedance and hence potentially reduce my attenuation level ????

A few other questions please (hope I'm not repeating stuff answered elsewhere)...

a) What is the score with the pin 3 connections??? why are they no needed these days? Does it have any negative effect disconnecting that pin?
b) What is the best wiring to use if I wanted to rewire some bits?
c) If I have phones in my house without a filter does it really matter?

Thanks in advance!

[Saturday]

Originally Posted by Christof

Anyway.. the real nub comes in trying to reduce my attenuation level, yes??

Do I assume correctly that if I clean all joint connection (maybe even solder the rubbish outside house)... also replace the master socket and maybe even replace some other internal wiring... I assume this will all reduce the total resistance/impedance and hence potentially reduce my attenuation level ????

If your line were in poor condition then you may find that in improving it the attenuation drops by one or two db. For it to drop much more than that then the line would have to be terrible and with your sync that doesn't look likely.

Originally Posted by Christof

a) What is the score with the pin 3 connections??? why are they no needed these days? Does it have any negative effect disconnecting that pin?
b) What is the best wiring to use if I wanted to rewire some bits?
c) If I have phones in my house without a filter does it really matter?

a) Terminal 3 is the ring wire used to generate the ring signal in old phones. Not generally needed in newer phones and absolutely not needed when filters are fitted (they generate it instead). The only negative to removing it might be for anyone who moves into your house after you and fits an old phone and no filter/ADSL.
b) Standard twisted pair is fine. Make sure it is kept away from power lines i.e. don't run alongside a power cable. If you need to cross a power cable then do it at right angles.
c) Yes, big time, unless you'd fitted a filtered faceplate to your master socket and your extensions were therefore filtered already.

[Christof]

Thank you sir.... just one final bit on the line 'quality'... is the attenuation not a result of total resistance/impedance.... mostly caused by the length of travel over copper from the exchange but presumably some (maybe a lot) caused by poor connections and suchlike ???

I have a different query about remote connection through to parents setup but I'll post that in a seperate thread.

Thanks.

[Saturday]

Attenuation (when referring to a phone line) is a measure of the loss of power between the transmission and reception points. This is largely a factor of the length of the line - though the line's electrical transmission properties can have an effect e.g. corrosion etc. Line length is by far the bigger factor.

Several things may alter the attenuation reading by a couple of db:

• measuring a different frequency (ADSL mode)
• using a different router (different makes/models can read differently)
• removing transmission interference (e.g. poor connections)

Line "quality" is more than attenuation. In particular it is about line noise. Whilst long lines will by their nature be more noisy than short, there are many other causes of line noise e.g. induced noise (rf is a particular problem to ADSL signals but less so to voice signals).