Upgraded from Mid to Max sync speed not as expected

[gordon]

I recently (yesterday) upgraded from Mid to Max with the expectation that I would achieve full speed on sync 16mbps. But I am syncing at 11696kbps. What I have noticed is that when on Mid my downstream noise margin was 15.5 (I always acheived 8190 kpbs downstream) but after the upgrade to Max the noise margin downstream has now gone down to (currently at 1745) 6.6. Would people comment on whether the drop from 15.5 to 6.6 noise margin would be expected when moving from Mid to Max as I think this is cause of lower than expected sync speed, I of course would like to see a 16meg sync!

The rest of the router stats
Speed 11696 764
Attenuation 27db 14.7db
Noise Margin 6.6db 12db

[Koala5]

The 15.5db is bug in the router firmware, had you rebooted at the time it would have most likely dropped. It's possible your current sync rate is due to line errors caused by either the line or internal extension wiring in your house, or some other piece of equipment plugged in. There's plenty of tips around the forum on telephone faceplate and wiring. Also if you have the old white router you can extract detailed stats on line errors etc, check out the stats threads.

Pardon me you posted in the stats section lol! Check the posts its all there!
Also Cabling and faceplate help - Sky User - The unofficial support forum for everything Sky!

[Saturday]

The 15.5db is bug in the router firmware

Indeed it is but it interferes with the correct display of the attenuation. The OP says the noise margin was 15.5db.

[gordon]

The 15.5 db bug is for downstream attenuation I am talking about downstream noise margin. I thought I would post in the router stats section because my expectation was that the my upgrade from Mid to max would give me a better sync speed.


Here are the full router stats

Status: Showtime Channel: FAST, Upstream rate = 764 Kbps, Downstream rate = 11696 Kbps
Link Power State: L0
Mode: ADSL2+
Channel: Fast
Trellis: ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 6.0 12.0
Attn(dB): 27.0 14.7
Pwr(dBm): 0.0 12.4
Max(Kbps): 11744 864
Rate (Kbps): 11696 764
G.dmt framing
K: 241(0) 24
R: 14 16
S: 1 8
D: 64 8
ADSL2 framing
MSGc: 92 68
B: 240 23
M: 1 8
T: 1 1
R: 14 16
S: 0.6565 7.7037
L: 3107 216
D: 64 8
Counters
SF: 379190 379188
SFErr: 377 1
RS: 37160642 3223098
RSCorr: 29931370 620756995
RSUnCorr: 2873 0

HEC: 306 0
OCD: 0 0
LCD: 0 0
Total Cells: 168276878 10979114
Data Cells: 196677 58981
Drop Cells: 0
Bit Errors: 0 0

ES: 811 1
SES: 147 0
UAS: 47 47
Total time = 7 hours 56 min 49 sec
SF = 1769757
CRC = 6832
LOS = 84
LOF = 0
ES = 811
Latest 1 day time = 7 hours 56 min 49 sec
SF = 1769757
CRC = 6832
LOS = 84
LOF = 0
ES = 811
Latest 15 minutes time = 11 min 49 sec
SF = 44128
CRC = 119
LOS = 6
LOF = 0
ES = 53
Previous 15 minutes time = 15 min 0 sec
SF = 55937
CRC = 182
LOS = 16
LOF = 0
ES = 72
Previous 1 day time = 0 sec
SF = 0
CRC = 0
LOS = 0
LOF = 0
ES = 0
15 minutes interval [-30 min to -15 min] time = 15 min 0 sec
SF = 56000
CRC = 53
LOS = 0
LOF = 0
ES = 37
15 minutes interval [-45 min to -30 min] time = 15 min 0 sec
SF = 55937
CRC = 15
LOS = 2
LOF = 0
ES = 12
15 minutes interval [-60 min to -45 min] time = 15 min 0 sec
SF = 55937
CRC = 2
LOS = 1
LOF = 0
ES = 3

[Koala5]

Indeed it is but it interferes with the correct display of the attenuation. The OP says the noise margin was 15.5db.

Note to self, "Read posts more carefully" The rest still apply's though.

[Koala5]

Total time = 7 hours 56 min 49 sec
SF = 1769757
CRC = 6832

Indeed your errors are high, First thing would be to check to see if your master socket has a hidden test socket behind the face plate, if it has plug your router direct in there as this disconnects all your extensions wiring if things improve you know it is your wiring causing the problem. Also check for an orange and white wire connected to pin 3 in all your sockets, if so disconnect it as it is not required and is know to cause noise problems.

[Saturday]

Would people comment on whether the drop from 15.5 to 6.6 noise margin would be expected when moving from Mid to Max as I think this is cause of lower than expected sync speed

You may be misunderstanding how this works.

The router negotiates on booting, the highest speed it can for a noise margin of 6.9db. From that moment on the noise margin will fluctuate depending on the noise on the line at that moment.

Rebooting will give you back 6.9db but the sync will change. That's because, for a given line condition (attenuation and noise) noise margin and sync are (inversely) related. Rather than explain it again here, please see the first sticky in my signature.

To answer your question: I wouldn't expect moving from a sync of 8190kbps to 11696kbps would give quite such a drop in noise margin but it has. Why? Probably because your line is rather noisy and ADSL2+ doesn't cope with this as well as G.DMT (especially with the V1 router firmware). Why do I think your line is noisy? Well your attenuation of 27db will easily support a sync of 16000kbps on a relatively quiet line. Your router isn't syncing anywhere near that high so that means your line isn't - quiet that is.

So in one way, yes the low noise margin is holding back your speed. You have a low noise margin/sync because your line is noisy. See the cabling and faceplate help forum for info and advice.

HTH



EDIT: your detailed router stats confirm that your line is very noisy. I'm surprised Sky didn't cap your connection when they moved you - they normally do when they see line errors like that. That's a good thing though as now when you sort your noise problem out the router will sync as fast as it can and you won't need to call Sky to get uncapped

[gordon]

Thanks for all your help - I am now going to tackle my wiring. Although the house is fairly new July 1999 and all the wiring was carried out by BT including four house extensions ( only two in use for Sky Digiboxes) it looks a bit of a mess. The drop cable comes up under a grey cover ( conduit) outside ony 18" inches long and on top of that is a grey plate - when I look under that the drop is crimped to the internal house wiring !(cheapo white cable), it looks like a birds nest, also from this point an outside extension has been taken (dont know whether this connected to the back of the master socket) round the back of the house into the lounge. The master socket is a LJU 4 I think twin outlet which has had a second line installed which is now ceased. I have requested via email to BT to change the LJU4 for an NTE5 master with ADSL filters. I tried phoning heldesk but got too fed up waiting. I know this going to cost but cannot see any other way around it as I musnt mess with the master. Or can I ?as the BT wiring drop cable is connected to the internal house wiring outside under this grey cover.

[IWasNotTheEnemy]

tbh some investment now will save a lot in the long run...

[Saturday]

I know this going to cost but cannot see any other way around it as I musnt mess with the master.

No you mustn't. Your side is from the socket backplate inward. BT's side is from the socket backplate back to the exchange. However, if BT did all the wiring including the extensions then I'd say you've got a pretty good chance that they'll fix whatever is needed free of charge. Just make sure you tell them that you have voice call problems such as an intermittent hiss/crackles (fax problems are even better). If you tell them it's an ADSL issue they won't help you.

They won't fit a filtered faceplate free unless they supply the ADSL - though you may find the engineer is amenable to doing it for a small consideration