Output power dropping

[aimdev]

Hi
My router/modem allows me to monitor among other things the output power.
The level has been constant for ages, but in the last week it has dropped from 12.5db to 10db and now 7db.
This appears to happen overnight, as I see the disconnect in the logging system.
The ul speed has dropped, from 1mbs to 796kbs, the loop attenuation is 29-30db, S/N 4db, the dl speed approx 17.5Mbs. ISP is Sky, service is adsl2+
My question is what would cause a drop in output power?

 

[Mark.J]

I assume you're only giving the downstream stats above? No upstream stats?

Ideally it would be good to see some before and after stats (full stats), as a single paste in isolation doesn't tell us all that much about how the conditions have altered. Likewise does your router track line errors? It would be good to know if you're seeing a lot more than usual.

Output power tends to reflect the amount of power being transmitted from your local exchange and your router (or at least the ADSL2+ modem inside your router). Usually the longer your copper line, the higher that output power figure will go and most ADSL lines tend to hover around 20db as roughly normal.

Strangely you seem to have an attenuation (assuming downstream) of c.29db and at that level I'd expect speeds of around 14-15Mbps at absolute best and not 17.5Mbps as stated. You might get to 17.5Mbps on a 25db but the line would have to be very good.

 

[aimdev]

Stats

Hi
The downstream attenuation according to the Draytek is 29/30 db, but according to the Sky SR102, 25db.
Here are the stats from the Draytek, sorry cant get them formatted any better.
Edit, these stats today, cannot get historical stats, but if the power changes, I will send another set.
In the meantime would be obliged if you could cast your eye over these stats to see if they look ok.
I am considering going to FTTC, not sure what speed I will get, any clues

Thanks


ATU-R Information
Type: ADSL2/2+
Hardware: Annex A
Firmware: 05-07-02-08-00-01
Power Mngt Mode: DSL_G997_PMS_L0
Line State: SHOWTIME
Running Mode: ADSL2+ Annex A
Vendor ID: b5004946 544e0000
ATU-C Information
Vendor ID: b5004244 434da3f7 [BDCM]
Line Statistics

Downstream Upstream
Actual Rate 17264 Kbps 796 Kbps
Attainable Rate 17476 Kbps 1105 Kbps
Path Mode Interleave Interleave
Interleave Depth 96 8
Actual PSD 16. 9 dB 10. 0 dB
Near End Far End
Trellis ON ON
Bitswap OFF ON
ReTx 0 0
SNR Margin 4 dB 13 dB
Attenuation 29 dB 14 dB
CRC 90 2
FECS 685014 s 20 s
ES 73 s 1 s
SES 0 s 0 s
LOSS 0 s 0 s
UAS 0 s 0 s
HEC Errors 0 82
RS Corrections 0 0
LOS Failure 0 0
LOF Failure 0 0
LPR Failure 0 0
NCD Failure 0 0
LCD Failure 0 0
NFEC 112 191
RFEC 16 12
LYSMB 235 4608

 

[Mark.J]

Purely looking at the core stats. Attenuation looks reasonable to me, although the SNR for upstream is perhaps a little high and I note there appear to be some HEC errors on the upstream side too. I certainly think you should be able to get a higher attainable upstream rate than 796Kbps, but without some more history for the line it's difficult to tell.

Upstream problems could also occur within your home and I'm wondering, do you get better speeds by using Sky's old router for a couple of weeks? The attenuation jump between those two is fairly noticeable and I wonder if the modem chipset isn't playing a small role here. Actually what stats do you get in general on Sky's router?

 

[aimdev]

Purely looking at the core stats. Attenuation looks reasonable to me, although the SNR for upstream is perhaps a little high and I note there appear to be some HEC errors on the upstream side too. I certainly think you should be able to get a higher attainable upstream rate than 796Kbps, but without some more history for the line it's difficult to tell.

Upstream problems could also occur within your home and I'm wondering, do you get better speeds by using Sky's old router for a couple of weeks? The attenuation jump between those two is fairly noticeable and I wonder if the modem chipset isn't playing a small role here. Actually what stats do you get in general on Sky's router?

Hi
Sky stats today below.
In the past I have tried a few modems(netgear & linksys), and the dl attenuation was about 28/29db.
I have noted that the Sky modem is always more optimistic with the attenuation, not sure why.
The ul speed has dropped recently, but it has been sub 1mbs before.
The drop in power and the decrease in ul speed are recent events, in the last 10 days.
I will be changing isp soon, and going to fttc, so hopefully any line issues will be resolved then.


Broadband Link Downstream Upstream
Connection Speed 18012 kbps 798 kbps
Line Attenuation 26.5 dB 15.6 dB
Noise Margin 6.1 dB 17.17 dB

 

[Kits]

I woud first put new micro filter on and buy a new RJ11 cable, best to get a sheilded RJ11 to help block noise from the home. Then see if the SNR and HEC errors go from upstream, anything causing problems on upstream is your side downstream Sky's.

 

[aimdev]

I woud first put new micro filter on and buy a new RJ11 cable, best to get a sheilded RJ11 to help block noise from the home. Then see if the SNR and HEC errors go from upstream, anything causing problems on upstream is your side downstream Sky's.

Hi
Thanks for the tips, actually I have been trying to find a compatible screened RJ11 cable for a while, as a precursor to going to fttc, plenty of adsl unscreened, but no vdsl screened cables, any suggestions would be useful.
The current cable is flat, adsl compatible allegedly, and its attenuation, adsl2 measurements, is 0.5db.
The micro filter is built into the master socket, only a couple of years old, not an official OpenReach one, not sure if the OpenReach ones are better.
I have done the master socket to modem micro filter test, no difference.

 

[aimdev]

I woud first put new micro filter on and buy a new RJ11 cable, best to get a sheilded RJ11 to help block noise from the home. Then see if the SNR and HEC errors go from upstream, anything causing problems on upstream is your side downstream Sky's.

Hi

re the HEC, always get around 120 errors on reboot or power up, then stable.

Still trying to source a shielded RJ11 cable prior to going to fttc.

Thanks

 

[Kits]

Depends on the length you want there are plenty on Amazon twisted pairs seem to be slightly better I have belkin highspeed internet which was bought from Amazon.

 

[aimdev]

Depends on the length you want there are plenty on Amazon twisted pairs seem to be slightly better I have belkin highspeed internet which was bought from Amazon.

Hi
yes I believe twisted pair is preferred for crosstalk reasons, also external screening would be an advantage.
At the moment I cannot move the modem closer to the master socket, and as stated earlier, 0.5db is the measure loss at adsl2+ frequencies with an unscreened twisted pair flat cable.. The length is approx 6m, which when added to the theoretical reach of 1400m is a lot. I will have a look to see if I can identify a cable type, though I did read somewhere that a cat5/6 cable may suffice.

 

[ManOfMeans]

Just to ask what problem are you having with the connection?

Is it intermittent, slow speeds anything that we can help with?

 

[aimdev]

Just to ask what problem are you having with the connection?

Is it intermittent, slow speeds anything that we can help with?

Hi
no its stable, however the ul speed has dropped a bit over the last two weeks, hence the drop in power level title.
Also I am trying to determine how to maximise the speed when I go to fttc, problem there is the dslam is too close to the exchange, but should provide a reasonable service, not super-fast, however trying to improve if possible the internal wiring.

 

[aimdev]

More Errors

Hi
no its stable, however the ul speed has dropped a bit over the last two weeks, hence the drop in power level title.
Also I am trying to determine how to maximise the speed when I go to fttc, problem there is the dslam is too close to the exchange, but should provide a reasonable service, not super-fast, however trying to improve if possible the internal wiring.

The current modem is racking up lots of crc and fec errors. Attenuation is about the same as previous, 29db.
The power level is down to 7db.
I have put on another modem(not the sky one), which has more information available, and
below are the statistics.

No other electrical equipment has been added to the property, the cabling is still the same and has worked of for over three years, with a drop of 0.5db.
Any ideas if its a start of a line fault?, which commenced as a step function on the 15-August at 00:54

Up time approx 6 hours.

Mode: ADSL2+
Line Coding: Trellis On
Status: No Defect
Link Power State: L0

Downstream Upstream
SNR Margin (dB): 6.2 16.0
Attenuation (dB): 28.5 14.7
Output Power (dBm): 8.6 19.7
Attainable Rate (Kbps): 20447 1024
Rate (Kbps): 16381 799
MSGc (number of bytes in overhead channel message): 87 14
B (number of bytes in Mux Data Frame): 54 10
M (number of Mux Data Frames in FEC Data Frame): 1 16
T (Mux Data Frames over sync bytes): 6 7
R (number of check bytes in FEC Data Frame): 6 16
S (ratio of FEC over PMD Data Frame length): 0.1159 7.5294
L (number of bits in PMD Data Frame): 4212 204
D (interleaver depth): 384 8
Delay (msec): 11 15

Super Frames: 883887 902316
Super Frame Errors: 318 0
RS Words: 493208940 3371111
RS Correctable Errors: 21039250 0
RS Uncorrectable Errors: 333 N/A

HEC Errors: 28 0
OCD Errors: 0 0
LCD Errors: 0 0
Total Cells: 557824447 104327663
Data Cells: 2969044 2060486
Bit Errors: 0 3075

Total ES: 316 0
Total SES: 0 0
Total UAS: 19 1223

 

[aimdev]

Well part of the problem was that one of the properties down the road had a dodgy cable which was causing problems, drop in attainable speed etc. Was interesting to watch the snr and speed raise when the OR guy disconnected the line to the affected property. New cable has been installed AFAIK, but the attainable speed is still below what it was when this all started, which according to my graphs was a step function, in the early hours. The output power has dropped to 7db.
In a few weeks I will be changing onto fttc, so they (OR) will have to fix it if its below the minimum.
My neighbour across the road from me, on the same cabinet, has said there is a drop of about 6Mbs on his line.

Was impressed when the OR guy got his REIN detector out, a tranny radio!!

He also confirmed the adsl2 attenuation, so a question, does anybody know the typical attenuation for the cable OR typically user per meter/foot/yard/fathom/furlong, I can convert these as I have a gce in maths and a calkulator

Why oh Why did they use RF down wires!!!

 

[konrado5]

aimdev: Could you paste your Hlog from DSLStats?
http://dslstats.me.uk/
I collect different hlogs in hope I will find similar to my.

 

[aimdev]

Hi
I dont use dslstats, I use a system based on snmp/telegraf/influxdb and grafana using linux, all in-house monitoring.
I am not familiar with an Hlog.
My router is not on the dslstats list.

 

[konrado5]

Hi
I dont use dslstats, I use a system based on snmp/telegraf/influxdb and grafana using linux, all in-house monitoring.
I am not familiar with an Hlog.
My router is not on the dslstats list.

Could you telnet to your modem and write "adslctl info --Hlog" or "adsl info --Hlog" or "xdslctl info --Hlog" and paste the results?

 

[aimdev]

Could you telnet to your modem and write "adslctl info --Hlog" or "adsl info --Hlog" or "xdslctl info --Hlog" and paste the results?

My router does not support those commands.
Is this what you require?
--------------------------- ATU-R Info (hw: annex A, f/w: annex A) -----------
Running Mode : ADSL2+ Annex A State : SHOWTIME
DS Actual Rate : 15358000 bps US Actual Rate : 799000 bps
DS Attainable Rate : 16584000 bps US Attainable Rate : 945000 bps
DS Path Mode : Interleave US Path Mode : Interleave
DS Interleave Depth : 384 US Interleave Depth : 8
NE Current Attenuation : 29 dB Cur SNR Margin : 6 dB
DS actual PSD : 18. 3 dB US actual PSD : 7. 1 dB
NE Rcvd Cells : 81260151 NE Xmitted Cells : 5326682
NE CRC Count : 36722 FE CRC Count : 12
NE ES Count : 30481 FE ES Count : 3
Xdsl Reset Times : 0 Xdsl Link Times : 1
ITU Version[0] : b5004946 ITU Version[1] : 544e0000
ADSL Firmware Version : 05-07-01-08-00-01
Power Management Mode : DSL_G997_PMS_L0
Test Mode : DISABLE
-------------------------------- ATU-C Info ---------------------------------
Far Current Attenuation : 14 dB Far SNR Margin : 15 dB
CO ITU Version[0] : b5004244 CO ITU Version[1] : 434da3f7
DSLAM CHIPSET VENDOR : < BDCM >

 

[fuad028]

Post deleted spammer
Details

Popsters IP appears in Stop forums spam database 66 times

Current country of origin: Bangladesh

 

[aimdev]

Post deleted spammer
Details

Popsters IP appears in Stop forums spam database 66 times

Current country of origin: Bangladesh

Hi
I think you are mis-understanding the reason for this thread.
The power output I am referring to is the amount of signal, in dB sent up the phone line to the exchange.
The frequencies are from approx 300khz to 2Mhz from adsl2+, vdsl are higher, but a long way from Wifi which is 2.4Ghz or 5Ghz.