|
|
Hi All
After much to and fro-ing Sky have realised that they haven't sent me a new modem for my new broadband connection as I had Sky broadband 3 years ago with them, so "already have a Sky router"... So I've dug it out of the loft...
Anyway - I'm not due to be activated until Monday 31st July, but turned my old Netgear DG834GT anyway as Sky reckon it'll "just work" when I'm activated.
Looking at the statistics area in the admin control panel on the router it's not returning anything under ADSL for noise etc. Can it only do that once my ADSL line is activated Monday?
Also, no lights on the front are doing anything, like flashing red or anything which I would have thought might happen if it couldn't connect to ADSL... might be wrong though? Only light is a green one for the wifi.
Just worried as I've not actually tested my telephone line (new property - no telephone), so just assumed the line is active after BT sent me a confirmation SMS and email.... eeeek! Also, old modem, in the loft for 3 years, scared it's not working!!
|
|
|
It is likely the work has not yet been done at the exchange, so you won't have any sync or stats showing on the device.
Always worth checking with a cheap corded phone to ensure the line is working as that may be the problem (plus, always good to have one laying around to check line quality).
Matt
|
|
|
Thanks Uno - you were right
I've now got my router up and running with working ADSL. They've kicked me off at 4096/512 kbps. My stats:
down/up
Line Attenuation: 11.0db/9.0db
Noise Margin: 27.3db/13.0db
Can anyone tell me what I should expect from those stats [from master socket]?
|
|
Register (or login) on our website and you will not see this ad.
|
|
|
EDIT: Duh, I confused NM & attn.
Full 24 Meg, assuming you are on ADSL2+ LLU.
1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 17 Meg Untweaked 19 Meg Tweaked WBC
Edited by XRaySpeX (Mon 01-Aug-11 22:13:50)
|
|
|
|
Thanks - How do I know if I'm on LLU ?
|
|
|
Do Exchange Search and see if Sky is listed as LLU.
1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 17 Meg Untweaked 19 Meg Tweaked WBC
|
|
|
|
Yeah its there... so I guess I just wait patiently now for 'training' to finish?
|
|
|
Also the starting you off at 4Meg on the Sky DLM system
|
|
The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
|
|
|
|
Sorry Andrew - what do you mean?
Also - is it normal for Line Attenuation to fluctuate? Overnight I'm now upto:
Speed: 6144/796 kbps
LA: 14.5/7.8 db
Noise: 29.8 / 15.5 db
I thought line attenuation would be static seeing as my house is not moving closer or further away from the exchange...?
|
|
|
Sky runs a system called Dynamic Line Management on its LLU product, which uniquely starts people off at 4Meg and then speeds you up hopefully.
Has the modem mode switched from ADSL to ADSL2+ mode. A change of around 3dB reflects a change from ADSL to ADSL2+ modes. This is down to the maths involved in calculating the attenuation across a range of frequencies
Line still has a lot more speed in it, www.farina1.com/adsl can give estimates based on your numbers. But with 11 to 14dB attenuation anything under 20Meg would be dissappointing
|
|
The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
|
|
|
Thanks for the info.. I'm not entirely sure how I check if I'm on ADSL 2+... I've got a Netgear DG834GT
I'm assuming my upload rate of 796 kbps could be an indication of that as standard ADSL is maxed at 512 kbps upload ??
Might be talking out of my bum on this
|
|
|
I'm not entirely sure how I check if I'm on ADSL 2+... I've got a Netgear DG834GT http://www.kitz.co.uk/routers/netgeardg834_interleav...
1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 17 Meg Untweaked 19 Meg Tweaked WBC
|
|
|
Standard ADSL - urm sorry standard ADSL has a limit around 800 to 1.1Mbps depending on hardware
ADSL Max sold by BT Wholesale generally has a 448 or 832Kbps limit depending on what you buy. So your upstream tells us nothing about whether ADSL2+ or ADSL
|
|
The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
|
|
|
|
Well, my router user/password will not work when trying to telnet onto the box... ?
|
|
|
|
Apparently Sky have disabled telnet on the DG834GT router which I have... so I'm stuck on not really knowing.
|
|
|
This was useful from the skyuser forums:
http://192.168.0.1/setup.cgi?...
I ran a search for 'mode' which shows I am on ADSL2+ 
Edited by deleted (Tue 02-Aug-11 12:57:03)
|
|
|
Ah, interesting! That works on my non-Sky DG834GT; last section is what we see with Telnet.
1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 17 Meg Untweaked 19 Meg Tweaked WBC
|
|
|
Overnight I'm now upto:
Speed: 6144/796 kbps
LA: 14.5/7.8 db
Noise: 29.8 / 15.5 db
I thought line attenuation would be static seeing as my house is not moving closer or further away from the exchange...? Are you sure that you haven't got the SNRM and attenuation figures mixed up? Looking at what you've shown, the following makes better sense --
Sync Speed: 6144 / 796 Kbps
SNRM: 14.5 / 7.8 dB
Attenuation: 29.8 / 15.5 dB
But I could be wrong! 
-----------------------------------------------------
100% Linux and, previously, Unix.
|
|
|
|
|
|
|
|
Just ensure you do not turn the router off during the first few weeks so DLM doesn't think the connections dropping
If you leave it on 24/7 you'll easily see the full 20 mbps in the next week or two.
|
|
|
I hope Sky's DLM is not that sensitive to devices being switched off. BT at least it took something like 10 disconnects in the space of an hour for it to get worried, and raise the margin.
|
|
The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
|
|
|
|
thanks - out of interest, how often does DLM make a change? Every 12 hours or so if it sees a good service after its last update?
|
|
|
|
I've restarted the router once by accident, it resynced back to what I had before...
|
|
|
Nope, they are right http://awesomescreenshot.com/0c7hs1ya6 As I now see. So you have good line attenuation and, currently, an extraordinary large downstream SNRM.
-----------------------------------------------------
100% Linux and, previously, Unix.
|
|
|
... and, currently, an extraordinary large downstream SNRM.
Is that a good thing? I am so close to the exchange, its about 100m away
|
|
|
With a stable line, I would expect to see a SNRM of 6 / 6 dB.
I don't know what target SNRM Sky use on their setup but if your SNRM does not start to drop over the coming days, then further investigations will be required.
For comparison purposes, here are the stats. from my (not-Sky) LLU'd line --
Downstream Bit Rate : 5216000 bps
Downstream Noise Margin : 6.0 dB
Downstream Attenuation : 51.5 dB
Upstream Bit Rate : 928000 bps
Upstream Noise Margin : 7 dB
Upstream Attenuation : 29.0 dB
-----------------------------------------------------
100% Linux and, previously, Unix.
|
|
|
|
sorry, n00b question - but how are you calculating SNRM?
|
|
|
sorry, n00b question - but how are you calculating SNRM? I'm not calculating it, the modem is displaying it. The Signal to Noise Ratio Margin (SNRM) is often erroneously referred to as the Signal to Noise Ratio (SNR), the Noise Ratio (NR), the Noise Margin (NM), etc.
So, while my values are 6.0 / 7.0 dB (target 6 dB), yours are 29.7 / 15.0 dB.
Please take a look at RobertoS' page that explains things quite nicely.
-----------------------------------------------------
100% Linux and, previously, Unix.
|
|
|
Right... I thought this number needs to be high? Really confused
http://www.kitz.co.uk/adsl/lowSNR.htm suggests a low SNR is bad?
|
|
|
Low NM => More speed, less stable.
High NM => More stable, less speed.
Need happy medium, commonly considered @ 6dB.
1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 17 Meg Untweaked 19 Meg Tweaked WBC
|
|
|
Right... I thought this number needs to be high? Really confused
http://www.kitz.co.uk/adsl/lowSNR.htm suggests a low SNR is bad? What would be bad is a low or high SNRM when compared with the defined target SNRM. You really need to find out (from documentation or by asking) what is Sky's default target SNRM and then contrast your observed values with that target.
Using my observed SNRM values as an example, where the target SNRM is set by my CP to be 6 dB, you can see that my values are neither too low nor too high.
-----------------------------------------------------
100% Linux and, previously, Unix.
|
|
|
The lowest SNR with sky is 6 / 7 DB
However Sky don't set a target SNR
Instead they set a sync speed
E.g. if your line is unstable. On most ISPs they will increase the SNR target from 6db to 9db. Everytime you sync you will achieve a SNR of 9db in future and the sync speed will vary with each resync (assuming your not on the max sync)
With Sky
They leave the SNR alone. Instead they set a lower sync speed.
E.g. Bob syncs currently at 10 meg with an SNR of 6.
Bobs line is unstable
Sky set Bobs maximum attainable sync to 9.1 meg. This is stable.
Now everytime you reboot that router it will sync at 9.1 meg. Even if you try and force the SNR down it will not work and the speed will not increase.
So Sky look at sync rather than just SNR. & they take into acount various factors to decide this sync.
EDIT: This means that Bob may reboot his router at 10am and get an SNR of 12db, and a sync of 9.1 mbps
If Bob reboots his router at 10pm he may see a SNR of 8db and again a sync of 9.1mbps
...obviously lowering sync increases the SNR naturally.
Edited by ukhardy07 (Tue 02-Aug-11 18:44:38)
|
|
|
|
OK, so ultimately, what does this mean for me? Is a downstream noise margin of 27 db too much?
Should I look at replacing the router to socket cable, and go into the test socket on the master?
|
|
|
OK, so ultimately, what does this mean for me? Is a downstream noise margin of 27 db too much?
Should I look at replacing the router to socket cable, and go into the test socket on the master?
Just leave it alone,although the margin is high at the moment Sky DLM is running this can take up to 10 days but usually is around 4-6,your router will resync around 2:30 am each morning and increase the sync rate until it hits maximum,you shouldn't have any trouble being set at 20Mb.
-----------------------------------------------------------------
Sky Broadband Unlimited LLU without TV
Line Rental/Calls IDNET
|
|
|
However Sky don't set a target SNR. Instead they set a sync speed.
They set both, with the target synch speed taking priority. If your line profile is set to a synch speed which is faster than your line can handle at 7dB of NM, then the target NM of 7dB will take effect.
Oliver.
|
|
|
Was wondering, as if they set a set fixed speed, then if there was a change in line conditions people would end up with no connection at all...
|
|
The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
|
|
|
Was wondering, as if they set a set fixed speed, then if there was a change in line conditions people would end up with no connection at all...
Yeah, whilst Sky's synch speed locking is a poor addition to their DLM, at least it has the sense to fall back to a target NM too.
Oliver.
|
|
|
|
Just an update... training continues, going up by 1Mbps each night it seems...
Now on:
DOWN/UP
8191/796 kbps Connection Speed
14.5/7.8 db Line Attenuation
25.3/14.5 db Noise Margin
Not much changing on the noise margin front... should I be concerned? I still don't really understand if I should other than it should be around 6db ?
|
|
|
Nothing to be concerned about really, even if DLM does mess up, Sky staff can always override it. Ultimately you will want your downstream noise margin at or near 7dB, if DLM doesn't do it then ask Sky staff for a manual profile change.
Oliver.
|
|
|
Those stats look similar to when I was on ADSL2+ LLU capped to 8 Meg, on a line capable of 16 Meg were it to be uncapped. The high NM was used to damp the speed down to 8 Meg.
Once Sky start raising your speed you should see a steady reduction in NM. You did see a decrease of 4.5 dB for an increase of 2047 Kbps in speed, which is about right.
1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 17 Meg Untweaked 19 Meg Tweaked WBC
|
|
|
Great, thanks guys for your feedback... Let's see what happens tomorrow, and if I get more speed, and another drop in db
|
|
|
|
So far so good guys, looks like the NM is going down after all:
11263 / 926 kbps Connection
14.5 / 7.8 db Line Attenuation
20.1 / 9.0 db Noise Margin
Thanks for all your help on this...
|
Pages in this thread: 
Print Thread
deleted
