|
Sky BB speed issues - improving a poor noise margin
As I've kind of hijacked the Sky BB 16meg thread from around page 5 onwards
http://www.cableforum.co.uk/board/sh...2&postcount=68 I thought I'd start a new one, just for my noise margin issues (& anyone else's if they want). I may try splitting & merging at some point, when I've got time to comb through the Sky 16meg thread. So, from here onwards: http://www.cableforum.co.uk/board/sh...8&postcount=83 Quote:
Ah, hence dragon's mention of the faceplate. Never mind, I can still try it. Googling "removing the ringwire" led me to http://www.kitz.co.uk/adsl/lowSNR.htm & http://www.clarity.it/telecoms/adsl_faceplate.htm amongst others. So, possible options could be.... 1) Remove the ringwire. (I assume the phones still ring, & it's easy to reconnect if/when I move properties?). EDIT: Yes they do - the phone ring is apparently powered by the microfilter so the ringwire (orange, IDC terminal 3) is completely unnecessary (& is a cause of problems anyway - poor noise margin). 2) Fit a filtered faceplate to the master, & connect the router to it's ADSL socket. [awkward position though, & an ADSL extension cable would be very inconvenient]. 3) Fit a modified filtered faceplate, such as the one Clarity sell, which has bits on the back to hardwire an ADSL extension to if you don't want to just plug the modem/router into the front ADSL socket (as well as the normal bits a filtered faceplate has to wire in normal phone extensions at the back). A new extension could then be run fed from the ADSL connections on the back of the faceplate - however, like option 2, an extension is not convenient. Current router stats, Sky BB "up to 16mbps": Quote:
Previous router stats, Firefly BB 2mbps: Quote:
|
Re: Speed issues - improving a poor noise margin
Just so that I don't have to trawl through that thread, have you had your line tested by the provider and did you try the test socket? If you tried the test socket and had the same results I would ask BT or whoever is currently parked on the line to sort it out as line noise can be caused by numerous reasons :(
|
Re: Speed issues - improving a poor noise margin
I assume that line tests were done when I first got ADSL a year ago, & again when I migrated from Firefly 2meg to Sky "up to 16 meg".
Or do you mean some sort of additional tests? I haven't tried the test socket yet - gonna do that at the weekend. |
Re: Speed issues - improving a poor noise margin
your downstream synch is better then expected at least, but poor for your attenuation.
My line is worse :( my current upstream noise is now pretty high and it can barely do 448kbit upstream. |
Re: Speed issues - improving a poor noise margin
Line attenuation does rise a little bit on ADSL2+
|
Re: Speed issues - improving a poor noise margin
line attenuation is static, on adsl2+ the reading is just taken firther up on the frequency range on a weaker part of the signal so reports a higher number.
|
Re: Speed issues - improving a poor noise margin
Right, I tried out the test socket this evening on the BT master.
Definite difference. Quote:
Quote:
Synch speed of 8096 suggests to me it's actually on ADSLMax up to 8meg, rather than ADSL2+ up to 16meg??? Noise margin is definitely better via the test socket. I ran some speed tests (CF, DSLZone, Dan Elwell's BB Speed Tester), yet they only came out slightly higher than what I get via the extension socket (between 3 & 4mbps for each socket, but closer to 4 for the test socket). |
Re: Speed issues - improving a poor noise margin
yeah the 8096 seems to indicate a 8meg cap. Still a bit low for your attenuation but that just goes to show attenuation isnt the be all and end all of what you will get only a rough idea. Your line probably has a bit more noise on it then the average line with the same attenuation.
It probably isnt adsl max and I think it is actually adsl2+ but capped as the other guy noticed your reported attenuation went up which is common with adsl2+ over adsl. Your router should be able to tell you if you using adsl or adsl+. If you are on adsl max tho then sky may charge you as I am fairly sure their prices are only lower for their LLU areas, and adsl max would indicate you not on LLU, also if its adsl max it explains why your speeds havent gone up as BT operate a poor BRAS rate limiting mechanism that keeps you throttled for 3 days after the increase in synch speed and if the synch speed remains stable it will then increase the rate limit. You already found the links yourself to ring wire websites so I guess you dont need to know what to do next. :) remember also http://yarwell.blogspot.com/2005_08_...l_archive.html linked from the website you mentioned. |
Re: Speed issues - improving a poor noise margin
OP is not on the non-LLU package, that only has an upstream of 448kbps as it's the BT Wholesale home max product. Definitely ADSL2+ which means capping at 16Mbit not 8.
|
Re: Speed issues - improving a poor noise margin
yeah sorry I didnt notice the upstream that defenitly explains why his speed hasnt improved as he will need to wait 3 days for BRAS to update. In that case 8096 with a 9db noise margin is pretty good then.
|
Re: Speed issues - improving a poor noise margin
No he won't. He's on LLU there is no BT style training period.
|
Re: Sky BB speed issues - improving a poor noise margin
Yeah, from looking around, seems it must still be the Sky LLU service, as the upstream is still a nice full 768kbps.
I disconnected the ring wire yesterday.... instant improvement. I now get the same stats as if it was connected to the test socket. Quote:
Did some speedtests at DSLZone...got a very nice 6meg, even with Alison downloading stuff at the same time. From having a look around ThinkBroadband (formerly ADSLGuide) & Skyuser.co.uk, it seems like Sky have a policy of capping people's speeds dependant on line quality, with some people also being put on G.DMT (?) rather than ADSL2+. It's apparently possible to get Sky to uncap your speed, & put you on ADSL2+, if you talk to "Tier3" tech support & they think your stats are good enough for it. Quote:
|
Re: Speed issues - improving a poor noise margin
Quote:
If he is on LLU it doesnt mean he is on adsl2+ sky also have a upto 8mbit LLU setting which may well use adsl1, the only way to know for sure is get the info from the router. Its also possible he is on adsl2+ but just capped at 8096. ---------- Post added at 15:10 ---------- Previous post was at 15:03 ---------- yeah not only are you on adsl1 then you are also on interleaving mode, interleaving increases your latency and decreases synch speed to provide extra error correction to increase stability. good lines shouldnt need interleaving but it helps on poor lines. I think you will benefit from adsl2+ so I would try and get on that if you can, I think its a strange policy from LLU providers to only allow the best lines on adsl2+ as it is beneficial in all regards even for larger lines since it has improvements in other things other then increased frequency range. |
Re: Sky BB speed issues - improving a poor noise margin
Yeah, I'm thinking of phoning Sky later in the week, to see if I can get through to "Tier3" & get them to try it out on ADSL2+.
|
Re: Sky BB speed issues - improving a poor noise margin
Quote:
|
Re: Sky BB speed issues - improving a poor noise margin
Quote:
Sky appear to put many people on G.DMT/Interleave, with a capped max speed, rather than ADSL2+/FastPath. They do this if they feel that your line is too poor for ADSL2+, too noisy. Sky's G.DMT can AFAIK go up to around 12mbps I think, while Sky's ADSL2+ currently tops out at 16mbps. When I first connected, I only squeezed a bit over 5mbps out of it, because of my high attenuation, & my low noise margin. After removing the ring wire, my noise margin increased, enabling me to connect at a higher speed - although it topped out at 8096kbps, as it had been capped by Sky at 8096 & was on G.DMT. "Tier 3" is the 3rd level of Sky BB tech support...... they can, if you badger them enough, & jump through hoops with Tier 1 & Tier 2 first, switch you from speed capped G.DMT to ADSL2+. However, if your speed sucks anyway there is little point. |
Re: Sky BB speed issues - improving a poor noise margin
adsl2+ has many advantages over adsl1. Greater efficency is one of them. Adsl2 is Adsl2+ but with only the Adsl1 range and without the extra frequencies it can still supply speeds upto 12mbit instead of 8mbit, I think the default sky is Adsl1 matt which would be a 8mbit limit.
https://www.cableforum.co.uk/images/...2007/03/18.png If I use my line as a example I would gain from adsl2+ over adsl1, the frequency between 794mhz and 932mhz would be used since adsl2 allows single bit tones and is less wasteful, and as you can see my useable SNR looks to carry on past beyond the 1.1mhz mark, speedwise I reckon I would gain around a mbit, which to me is good but an isp would probably think not worth bothering with and since I have a 48db attenuation I expect I would be one of those people denied adsl2+. Adsl2+ also increases reliability and reduces crosstalk so there is really no reason other then old hardware compatability to use Adsl1 instead. |
Re: Sky BB speed issues - improving a poor noise margin
Interesting :tu:
|
Re: Sky BB speed issues - improving a poor noise margin
Can anyone gives these stats a look over?
Quote:
|
Re: Sky BB speed issues - improving a poor noise margin
Oh, for a nice error-free line with low attenuation :(
You're on ADSL2+ & FastPath, rather than G.DMT & Interleave :tu: Your attenuation is low enough that you could potentially connect at the full 16Mbps. But, due to the noise margin, you're actually connecting at around 13Mbps. Have you tried the suggestions Chrysalis gave me earlier in this thread & the other Sky BB thread? i.e. try the test socket on the BT Master (behind the faceplate) to rule in/out any local wiring issues, & try disconnecting the ring wire? From your brief bit of uptime, you've had no Error Seconds (ES) [apart from a single one going upstream], no Serious Error Seconds (SES), no Loss of Signal (LOS), & no CRC errors (CRC) :tu: [although a better test would be a few hours of up time at least, while using the connection] You may find these handy: http://www.skyuser.co.uk/forum/speed...explained.html http://www.skyuser.co.uk/forum/route...ter-stats.html |
Re: Sky BB speed issues - improving a poor noise margin
Seem to have an issue with the connection going slow till router reboot about one a day, posted on the sky user forum too. Will try the master socket later to see if that resolves it
Here are the stats from the morning after the problem believed to have occured: Quote:
|
Re: Sky BB speed issues - improving a poor noise margin
Using the test socket behind the master gives
Quote:
|
Re: Sky BB speed issues - improving a poor noise margin
2nd stats...
Loads of errors! More than me, even. 3rd stats... Seems a lot of errors, for only 8mins uptime. Much better noise margin & synch speed using the test socket though :tu: Have you considered removing the ringwire, getting an ADSL faceplate, improving extension wiring, etc. etc.? http://www.skyuser.co.uk/forum/cabling-faceplate-help/ http://www.cableforum.co.uk/board/34254181-post2.html For a proper look at your stats, I'd wait for Mossywell or Saturday at Skyuser to comment on them...they're the router gurus over there. Noise margin varies through the day. When it gets really low, the connection can drop. However the Sky router does not always seem to realise when the connection has gone down, & so doesn't then reconnect. A reboot sorts it, as the router then reconnects at a better speed for the current noise margin. Maybe that's your problem, or part of it. Mossywell at Skyuser has created "Bounce Sky Router", a little system tray app which monitors the internet connection & automatically reboots the router when the connections drops. You can also use it to issue custom commands, such as telling the router to resynch at a particular noise margin. http://www.skyuser.co.uk/forum/techn...matically.html |
Re: Sky BB speed issues - improving a poor noise margin
1 Attachment(s)
Another thing, shortly after reconnecting my router i got the normal noise margin then got this thing.
Rebooting restored it to normal. Rewiring is out of the question and I don't think it will help much by the looks. Will look at getting the ring wire out. |
Re: Sky BB speed issues - improving a poor noise margin
There's a bug apparently which makes it report crazy noise margins sometimes.
Re-wiring is always worth it, if possible. Removing the ring wire should at least make an improvement. Also, even if you can't re-wire the extensions completely, it is still very easy, & definitely worthwhile, putting an ADSL faceplate on the master (depending on how your extensions are wired & used), or at least replacing the bog standard microfilters with decent ADSL Nation filters (either dangly ones, or complete replacement extension sockets with built-in filters). |
Re: Sky BB speed issues - improving a poor noise margin
It is a brand new renovated house, I don't think rewiring something 3 months old would go down well.
|
Re: Sky BB speed issues - improving a poor noise margin
LOL, probably not.
Still cheap, quick, & easy to remove the ringwire, change the faceplate, put filtered extension sockets on in place of "normal extension socket plus cheapo dangly filter" etc. Also easily reversible. I rent with my fiancée. Can't go running new extensions everywhere in place of the existing "behind the walls" cables, but have at least done the ringwire, faceplate, & extension sockets. If/when we move, it won't take long to change back. |
Re: Sky BB speed issues - improving a poor noise margin
OK. I've installed an adslnation XTE-2005. The only phone line extension is filtered at the master faceplate and the I have a short adsl extension unfiltered for the adsl modem. Removed ringwire.
So far stats are: but the real test will come weekday nights. Quote:
|
Re: Sky BB speed issues - improving a poor noise margin
Looks like no dice. The noise margin stay relatively high but around 20:00 crc errors surge
Quote:
|
| All times are GMT +1. The time now is 20:40. |
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, vBulletin Solutions Inc.
All Posts and Content are © Cable Forum