Sync speed & Noise margin
This is a discussion on Sync speed & Noise margin within the Sky Broadband help forums, part of the Sky Broadband help and support category; @ LuckyKnight Your connection doesn't sound too good. I reckon you'll have to go back to Sky T3. I got ...
- 21-09-06, 10:07 PM #121
Your connection doesn't sound too good. I reckon you'll have to go back to Sky T3.
I got a BT engineer out. He cleaned up the connection in the outside box then replaced the old mastersocket with a new filtered one. He also replaced an old filtered socket on another ADSL line I have as he said they tend to degrade after a few years.
- 21-09-06, 10:12 PM #122
I realise that the reason my connection is now stable (60 hours +) after loads of disconnects for the first few days is that my sync has now dropped from 15000kbps to 9000kbps. I have never phoned up Support to ask them to lower the sync, though I was thinking of doing so, so either Sky are monitoring lines anyway, and have tweaked the line, or the ADSL2+ firmware has re-trained the line. Either way I am happy because the max speed I have had is 8444 on Speedtest, so it's been set to a reasonable level. Perhaps all my reboots finally alerted someone or some software that something needed to be done.
- 21-09-06, 10:37 PM #123
Who did you call (at BT)? Was it free?
It is turned on by default and can add as much as 30ms to your ping. When hosting games that is doubled (back and forward). You need to be very determined to get to tier 3, to get past the noob CS agents.
My db is contantly fluctuating below 6db causing break up on Skype, slow websites etc. I will have to speak to them again tomorrow Or maybe I should call BT but I guess they will take there time.
- 21-09-06, 10:44 PM #124
BT. It is free if you have a fault with your line/mastersocket. I gave the engineer something for his trouble
- 21-09-06, 11:07 PM #125
IQ album "Dark Matter" artwork reproduced with permission. See www.gep.co.uk/iq for more information.
- 22-09-06, 12:44 PM #126
Rebooting every 24 Hours
I have been very pleased with Sky. In terms of signing me up, sending me the router, activating the service and sticking to agreed dates they have been excellent. But...you knew there would be a but!.....I am having trouble maintaining a useable and stable connection. I signed up for the MAX package even though I knew I would only be able to get 3.5Mb download speed (I need the uncapped user limit). Once activated I achieved this speed immediately. But within around 8 hours my speed had collapsed to sub-dialup levels and I could no longer load web pages. The router reported I was still connected. A reboot of the router brought me back up to 3.5Mb but the problem recurs every 24 hours. My PC is off over night and when I boot up first thing in the morning I ALWAYS have to reboot the router before I can get on line.
Sky technical support (0800 0510317) have been very helpful. I eventually got through to Tier 3 support (long wait - make sure you use that 0800 number!) who reduced my line speed to 3Mb in the hope of improving stability. It hasn't helped. My SNR was 6db before my speed was capped and this has now risen to 11db. But my signal still fades away over time. When it does so, the SNR is reading no more than 6 or 7db.
Would a further capping of my line help? My attenuation figure is high (59db) because I am a couple of km from the exchange. I would be happy to have, say, a 2Mb service that was ultra reliable than a 3Mb one that is flaky.
Would a change of package help? Am I more prone to problems being on the MAX service? Would a step down to MID help me if I could live with the 40Gb cap?
Any advice appreciated.
- 22-09-06, 02:00 PM #127
Well as for the topic about the ADSL faceplates from ADSL Nation. I have received one today and my router is reporting a slightly worse connection!
I've noticed that the faceplate has extension for both voice and ADSL at the back plate - surely the latter would reduce the connection stats because of a un-needed unwired extension?
DSL Link Downstream Upstream
Connection Speed 7999 kbps 983 kbps
Line Attenuation 43.5 db 26.3 db
Noise Margin 8.3 db 6.0 db
Supplied micro filter:
ADADSL Link Downstream Upstream
Connection Speed 7999 kbps 990 kbps
Line Attenuation 43.0 db 26.2 db
Noise Margin 8.7 db 5.5 db
Your not the only one with this problem! The web just dies, skype breaks up, torrents go down to 0. Usually a reboot fixes it.
It does not lose sync.
- 22-09-06, 02:43 PM #128
Couple of things: firstly the difference is not statistically significant. Try taking 100 measurements with each faceplate and you'll see what I mean! Secondly, the ADSL Nation kit does sometimes report a fall in the SNR. However, don't get too hung up about that because the SNR is averaged over usable frequencies. Cheaper filters have reduced usable frequencies, but the ADSL Nation ones can use a greater frequency range including those with more noise. So, when the SNR is averaged out across all usable bands, it is lower but the bandwidth is actually higher. The lesson is that meaning of a SNR is dependent on many factors and to compare them without taking into account a zillion other things is likely to lead to invalid conclusions.
MIQ album "Dark Matter" artwork reproduced with permission. See www.gep.co.uk/iq for more information.
- 22-09-06, 03:04 PM #129
You're not alone with this problem. When your connection drops, reboot your router. It will resync at a slightly lower speed but more importantly at a higher noise margin. You may have to do this more than once in an evening depending how bad your problem is.
Now leave your router on (that's what they're designed to be). From then on you wont have a problem unless you lose power to the router.
If you feel you must turn off your router then you'll have to call Sky and ask them to cap your connection.
- 22-09-06, 03:08 PM #130