Sky BB speed issues - improving a poor noise margin

[Tezcatlipoca]

Originally Posted by bluecandylover

May I ask what you mean by getting though to Tier3 CS?

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.

[Chrysalis]

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.



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.

[Tezcatlipoca]

Interesting

[downquark1]

Can anyone gives these stats a look over?

/usr/sbin/adslctl: ADSL driver and PHY status
Status: Showtime Channel: FAST, Upstream rate = 764 Kbps, Downstream rate = 13368 Kbps
Link Power State: L0
Mode: ADSL2+
Channel: Fast
Trellis: ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 7.1 12.0
Attn(dB): 27.0 14.4
Pwr(dBm): 1.3 12.4
Max(Kbps): 13428 864
Rate (Kbps): 13368 764
G.dmt framing
K: 241(0) 24
R: 14 16
S: 1 8
D: 64 8
ADSL2 framing
MSGc: 106 68
B: 240 23
M: 1 8
T: 1 1
R: 14 16
S: 0.5744 7.7037
L: 3551 216
D: 64 8
Counters
SF: 127354 127352
SFErr: 0 1
RS: 14263706 1082492
RSCorr: 1333372 0
RSUnCorr: 0 0

HEC: 0 0
OCD: 0 0
LCD: 0 0
Total Cells: 64597712 3664628
Data Cells: 262216 39185
Drop Cells: 0
Bit Errors: 0 0

ES: 0 1
SES: 0 0
UAS: 14 16
Total time = 34 min 28 sec
SF = 127354
CRC = 0
LOS = 0
LOF = 0
ES = 0
Latest 1 day time = 34 min 28 sec
SF = 127354
CRC = 0
LOS = 0
LOF = 0
ES = 0
Latest 15 minutes time = 4 min 28 sec
SF = 16720
CRC = 0
LOS = 0
LOF = 0
ES = 0
Previous 15 minutes time = 15 min 0 sec
SF = 55939
CRC = 0
LOS = 0
LOF = 0
ES = 0
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 = 54695
CRC = 0
LOS = 0
LOF = 0
ES = 0

[Tezcatlipoca]

Oh, for a nice error-free line with low attenuation



You're on ADSL2+ & FastPath, rather than G.DMT & Interleave

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) [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

[downquark1]

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:

/usr/sbin/adslctl: ADSL driver and PHY status
Status: Showtime Channel: FAST, Upstream rate = 764 Kbps, Downstream rate = 13184 Kbps
Link Power State: L0
Mode: ADSL2+
Channel: Fast
Trellis: ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 8.9 12.5
Attn(dB): 27.0 14.4
Pwr(dBm): 1.3 12.4
Max(Kbps): 13244 864
Rate (Kbps): 13184 764
G.dmt framing
K: 241(0) 24
R: 14 16
S: 1 8
D: 64 8
ADSL2 framing
MSGc: 104 68
B: 240 23
M: 1 8
T: 1 1
R: 14 16
S: 0.5825 7.7037
L: 3502 216
D: 64 8
Counters
SF: 8244755 8244753
SFErr: 2147048 1
RS: 906923150 70080400
RSCorr: 828656109 864134
RSUnCorr: 13918739 0

HEC: 1959498 0
OCD: 1 0
LCD: 0 0
Total Cells: 4090859504 238048015
Data Cells: 50959618 39208712
Drop Cells: 0
Bit Errors: 0 0

ES: 52940 1
SES: 41279 0
UAS: 14 35
Total time = 1 days 12 hours 41 min 36 sec
SF = 8244755
CRC = 2147048
LOS = 1993
LOF = 0
ES = 52940
Latest 1 day time = 12 hours 41 min 36 sec
SF = 2852583
CRC = 2065971
LOS = 467
LOF = 0
ES = 43879
Latest 15 minutes time = 11 min 36 sec
SF = 43438
CRC = 40945
LOS = 33
LOF = 0
ES = 694
Previous 15 minutes time = 15 min 0 sec
SF = 56233
CRC = 52963
LOS = 65
LOF = 0
ES = 871
Previous 1 day time = 24 hours 0 sec
SF = 5392172
CRC = 81077
LOS = 1526
LOF = 0
ES = 9061
15 minutes interval [-30 min to -15 min] time = 15 min 0 sec
SF = 56170
CRC = 52979
LOS = 71
LOF = 0
ES = 900
15 minutes interval [-45 min to -30 min] time = 15 min 0 sec
SF = 56171
CRC = 53165
LOS = 76
LOF = 0
ES = 899
15 minutes interval [-60 min to -45 min] time = 15 min 0 sec
SF = 56170
CRC = 53521
LOS = 56
LOF = 0
ES = 900

[downquark1]

Using the test socket behind the master gives

/usr/sbin/adslctl: ADSL driver and PHY status
Status: Showtime Channel: FAST, Upstream rate = 764 Kbps, Downstream rate = 15323 Kbps
Link Power State: L0
Mode: ADSL2+
Channel: Fast
Trellis: ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 10.9 13.0
Attn(dB): 25.0 13.9
Pwr(dBm): 1.3 12.4
Max(Kbps): 17552 864
Rate (Kbps): 15323 764
G.dmt framing
K: 239(0) 24
R: 16 16
S: 1 8
D: 64 8
ADSL2 framing
MSGc: 59 68
B: 238 23
M: 1 8
T: 2 1
R: 16 16
S: 0.4980 7.7037
L: 4096 216
D: 64 8
Counters
SF: 8399 8397
SFErr: 0 1
RS: 1091980 71374
RSCorr: 39 0
RSUnCorr: 0 0

HEC: 0 0
OCD: 0 0
LCD: 0 0
Total Cells: 4937400 211587
Data Cells: 6655 692
Drop Cells: 0
Bit Errors: 0 0

ES: 2 1
SES: 2 0
UAS: 56 60
Total time = 8 min 43 sec
SF = 26743
CRC = 195
LOS = 8
LOF = 0
ES = 2
Latest 1 day time = 8 min 43 sec
SF = 26743
CRC = 195
LOS = 8
LOF = 0
ES = 2
Latest 15 minutes time = 8 min 43 sec
SF = 26743
CRC = 195
LOS = 8
LOF = 0
ES = 2
Previous 15 minutes time = 0 sec
SF = 0
CRC = 0
LOS = 0
LOF = 0
ES = 0
Previous 1 day time = 0 sec
SF = 0
CRC = 0
LOS = 0
LOF = 0
ES = 0

[Tezcatlipoca]

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

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

[downquark1]

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.

[Tezcatlipoca]

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).

[downquark1]

It is a brand new renovated house, I don't think rewiring something 3 months old would go down well.

[Tezcatlipoca]

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.

[downquark1]

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.

/usr/sbin/adslctl: ADSL driver and PHY status
Status: Showtime Channel: FAST, Upstream rate = 764 Kbps, Downstream rate = 15323 Kbps
Link Power State: L0
Mode: ADSL2+
Channel: Fast
Trellis: ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 9.4 13.0
Attn(dB): 27.0 14.5
Pwr(dBm): 921.6 12.4
Max(Kbps): 16644 864
Rate (Kbps): 15323 764
G.dmt framing
K: 239(0) 24
R: 16 16
S: 1 8
D: 64 8
ADSL2 framing
MSGc: 59 68
B: 238 23
M: 1 8
T: 2 1
R: 16 16
S: 0.4980 7.7037
L: 4096 216
D: 64 8
Counters
SF: 63619 63617
SFErr: 0 1
RS: 8270572 540744
RSCorr: 17683 0
RSUnCorr: 0 0

HEC: 0 0
OCD: 0 0
LCD: 0 0
Total Cells: 37238760 1835189
Data Cells: 57777 102240
Drop Cells: 0
Bit Errors: 0 0

ES: 0 1
SES: 0 0
UAS: 14 396
Total time = 17 min 29 sec
SF = 63619
CRC = 0
LOS = 0
LOF = 0
ES = 0
Latest 1 day time = 17 min 29 sec
SF = 63619
CRC = 0
LOS = 0
LOF = 0
ES = 0
Latest 15 minutes time = 2 min 29 sec
SF = 9265
CRC = 0
LOS = 0
LOF = 0
ES = 0
Previous 15 minutes time = 15 min 0 sec
SF = 54354
CRC = 0
LOS = 0
LOF = 0
ES = 0
Previous 1 day time = 0 sec
SF = 0
CRC = 0
LOS = 0
LOF = 0
ES = 0

[downquark1]

Looks like no dice. The noise margin stay relatively high but around 20:00 crc errors surge

/usr/sbin/adslctl: ADSL driver and PHY status
Status: Showtime Channel: FAST, Upstream rate = 764 Kbps, Downstream rate = 15323 Kbps
Link Power State: L0
Mode: ADSL2+
Channel: Fast
Trellis: ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 8.3 12.5
Attn(dB): 27.0 14.5
Pwr(dBm): 844.8 12.4
Max(Kbps): 16644 864
Rate (Kbps): 15323 764
G.dmt framing
K: 239(0) 24
R: 16 16
S: 1 8
D: 64 8
ADSL2 framing
MSGc: 59 68
B: 238 23
M: 1 8
T: 2 1
R: 16 16
S: 0.4980 7.7037
L: 4096 216
D: 64 8
Counters
SF: 2151908 2151906
SFErr: 50705 3
RS: 279748150 18291201
RSCorr: 594136 99
RSUnCorr: 118152 0

HEC: 50026 5
OCD: 23 0
LCD: 0 0
Total Cells: 1258619371 62716990
Data Cells: 22711636 20539875
Drop Cells: 0
Bit Errors: 0 0

ES: 1185 2
SES: 866 0
UAS: 14 396
Total time = 9 hours 40 min 51 sec
SF = 2151908
CRC = 50705
LOS = 0
LOF = 0
ES = 1185
Latest 1 day time = 9 hours 40 min 51 sec
SF = 2151908
CRC = 50705
LOS = 0
LOF = 0
ES = 1185
Latest 15 minutes time = 10 min 51 sec
SF = 40272
CRC = 16658
LOS = 0
LOF = 0
ES = 398
Previous 15 minutes time = 15 min 0 sec
SF = 55590
CRC = 27105
LOS = 0
LOF = 0
ES = 576
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 = 55591
CRC = 6855
LOS = 0
LOF = 0
ES = 163
15 minutes interval [-45 min to -30 min] time = 15 min 0 sec
SF = 55652
CRC = 43
LOS = 0
LOF = 0
ES = 22
15 minutes interval [-60 min to -45 min] time = 15 min 0 sec
SF = 55591
CRC = 1
LOS = 0
LOF = 0
ES = 1