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[oliver602]

Hi,

I think I have identified REIN on our phone line using an AM radio. With the power off and extension wiring disconnected I can hear a distinct noise from the radio while it is close to the drop cable at certain times of the day. Either a short buzz at half second intervals, or continuous crackling. It never causes the connection to resync, even if it stops functioning from too many CRC errors.

The line works fine while this noise is present if the  SNR margin is high enough. I tested 9dB during the noise with no packet loss.

My question is would BT consider this a fault if the line can function at a reduced sync? Concerned about being charged the crazy engineer fee.

My ISP (Xilo) has been very helpful. I wanted to get some more opinions or perhaps hear other peoples experiences with external REIN issues.

My line stats are also on mydslwebstats.co.uk

Code: [Select]

Max:    Upstream rate = 1112 Kbps, Downstream rate = 6480 Kbps
Bearer: 0, Upstream rate = 1020 Kbps, Downstream rate = 5583 Kbps

Link Power State:       L0
Mode:                   ADSL2+
TPS-TC:                 ATM Mode
Trellis:                U:ON /D:ON
Line Status:            No Defect
Training Status:        Showtime
                Down            Up
SNR (dB):        5.8             8.7
Attn(dB):        44.5            19.6
Pwr(dBm):        0.0             12.6

                        ADSL2 framing
                        Bearer 0
MSGc:           56              10
B:              60              145
M:              4               1
T:              3               1
R:              10              0
S:              1.3908          4.5447
L:              1461            257
D:              32              1

                        Counters
                        Bearer 0
SF:             28200563                163642
SFErr:          929404          2112
RS:             1311326101              1812110
RSCorr:         51912113                0
RSUnCorr:       5939996         0

                        Bearer 0
HEC:            4655898         1692
OCD:            0               0
LCD:            0               0
Total Cells:    1704436024              1096524533
Data Cells:     450607420               29200216
Drop Cells:     0
Bit Errors:     0               117247

ES:             178656          1700
SES:            1420            0
UAS:            175             175
AS:             455959

                        Bearer 0
INP:            0.50            0.00
INPRein:        0.00            0.00
delay:          11              1
PER:            16.16           18.17
OR:             30.67           7.04
AgR:            5592.07 1024.00

Bitswap:        61575/62037             21049/21136

Total time = 1 days 5 hours 10 min 42 sec
FEC:            73775122                0
CRC:            1447573         2794
ES:             178656          1700
SES:            1420            0
UAS:            175             175
LOS:            0               0
LOF:            0               0
LOM:            0               0
Latest 15 minutes time = 10 min 42 sec
FEC:            280413          0
CRC:            4617            0
ES:             617             0
SES:            2               0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
Previous 15 minutes time = 15 min 0 sec
FEC:            397751          0
CRC:            6873            0
ES:             854             0
SES:            10              0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
Latest 1 day time = 5 hours 10 min 42 sec
FEC:            7026662         0
CRC:            127728          163
ES:             17716           95
SES:            74              0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
Previous 1 day time = 24 hours 0 sec
FEC:            6193083         0
CRC:            87744           255
ES:             12771           176
SES:            99              0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
Since Link time = 5 days 6 hours 39 min 19 sec
FEC:            51912113                0
CRC:            929404          2112
ES:             122881          1280
SES:            783             0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0



[konrado5]

I can't help with this issue. But for my curiosity: could you attach your Hlog and QLN?

[oliver602]

I'm on a TTB LLU service. I was on a profile that gave me 15dB noise margin with fast path and it really struggled with the noise. On interleaving now (with a lower noise margin) which has helped.

Hlog and QLN attached

[kitz]

Ye gawds, that certainly is a noisy line.

Aside from all the squiggles, the variance between 4dB and 10dB I'd consider excessive for as 45dB line.

>> My question is would BT consider this a fault if the line can function at a reduced sync? Concerned about being charged the crazy engineer fee.

Thats the 64 million dollar question.  Youre going to need the support of your ISP on this one.
Its unlikely that the first engineer will be specialised enough to understand REIN.  A few ISPs such as AAISP, Zen and even PN would take the results of that graph and try push things for you.  It will likely take several visits to get resolved and you will obviously have to make sure that its not coming from your own equipment. 

You may be lucky and get an engineer who understands things like SNR Margin and REIN and not one who says, well its syncing ok whats the problem.   I would also be inclined to show the engineer (and of course your ISP) those graphs.

I cant say for sure whether or not you will be charged... I dont know how pro-active Xilo are in cases such as this.   It will be frustrating at times, but I would be hopeful that a line showing that much noise could eventually be resolved. 

[Loading]

If I am correct that QLN looks like its got Earth Contact?

[Black Sheep]

No idea about the QLN graph, but I can tell you that an earth fault would be heard on the telephony (PSTN) side of the circuit.
If the OP lifts his (preferably corded) handset and just dials any one digit (to break dial tone), then if there is a 'humming' noise in the background this would prop up your own thoughts, Loading ?. 

[oliver602]

Thanks all, using a corded phone(BT branded bought just for testing) there is a very small amount of noise, 50Hz hum and white noise from the modem, but you have be in a quiet room to hear it. Certainly wouldn't hear it over a conversation on the phone. So slight I figured it was normal.

Choice from Xilo is increase SNR margin or go ahead with SFI visit. I know a higher SNR margin will make the line stable(tried it on a Billion 7800X) but really don't want to take the speed hit permanently. Undecided at this moment. Getting time off work is going to be a pain. And explaining the alleged issue to the engineer.