SNR pre-post reset

[#1]

Hi attached is a graph of my snr pre/post either a forced disconnection (pull phone line) or a router reset.

My question is, why does the snr stabilise as the line conditions have not changed (same line/same dslam/same exchange)

Is this variation in snr due to interference?, if so why does it not continue fluctuating?

Thanks

[#2]

How do you know that this is in any way connected to a disconnection?

It's interesting that the SNR is increasing, not decreasing. The question has to be: what's happening to your sync speed? If that's stable it suggests to me that you are seeing a decrease in background noise during this period.

[#3]

@Baldrick1 makes a good point here. 

Can you let us know @dws1900? 

Thanks, 

MoR

[#4]

@Baldrick1 

@MasterOfReality 

Hi

I don't know if it is or isn't connected to a disconnection.

Here is a more complete picture.

The modem is a Vigor 2860, and over a longer periods there is a rough pattern, 08:00 - 12:00 and 16:00 - 2300.

DSLAM is a Huawei

[#5]

Hi @dws1900,

I have tested the line form our end of things and the sync speed looks fine, though I can see that there's been some disconnections over the last few days. It's not at the level that we'd consider it a fault and we also don't know what's caused the drops (meaning it may be down to router reboots), but it could be that this is related to the SNR variation. Could you advise if these connection drops are down to router reboots or if they are unknown to you?

[#6]

@TheMightyAJ 

The disconnects were due to my tests, the phenomenon of the snr has occurred prior to the disconnects.

One issue is the line is way too long, and overloaded, this is being investigated outside of the ISP's (PlusNet) domain and cannot be commented here.

Thanks for the line check, if you have a moment an up to date GEA/whatever its called test would be helpful.

[#7]

Thanks for getting back to us @dws1900

I've provided a copy of the latest GEA test below

Test Outcome	Pass
Test Outcome Code	GTC_FTTC_SERVICE_0000
Description	GEA service test completed and no fault found .
Main Fault Location	OK
Sync Status	In Sync
Downstream Speed	21.6 Mbps
Upstream Speed	2.0 Mbps
Appointment Required	N
Fault Report Advised	N
NTE Power Status	PowerOn
Voice Line Test Result	Pass
Bridge Tap	Not Detected
Radio Frequency Ingress	Not Detected
Repetitive Electrical Impulse Noise	Not Detected
Cross Talk	Detected
Estimated Line Length In Metres	1509.1
Upstream Rate Assessment	Very Good
Downstream Rate Assessment	Very Good
Interference Pattern	Not Detected
Service Impact	No Impact Observed
Home Wiring Problem	Not Detected
Downstream Policing Discard Rate	0.0
Customer Traffic Level	Upstream and Downstream Traffic Detected
Technology	VDSL
Current 15Min Bin Retrains	0
Last 15Min Bin Retrains	0
DP Type	External
Profile Name	0.128M-40M Downstream 3dB, Retransmission Low - 0.128M-10M Upstream, Error Protection Off
Time Stamp	2019-09-12T10:00:00

Parameters	MIN	MAX	AVG
Down Stream Line Rate	21.5 Mbps	21.8 Mbps	21.6 Mbps
Up Stream Line Rate	1.9 Mbps	2.0 Mbps	1.9 Mbps
Up Time	0.0 Sec	900.0 Sec	873.3 Sec
Retrains	0.0	1.0	0.0

Current and Last 15 Minute Bin Performance
Parameters	Last Traffic Count(Upto 15 mins)	Current Traffic Count(Upto 15 mins)
Start Time Stamp	2019-09-25T08:31:15Z	2019-09-25T08:46:15Z
Ingress Code Violation	2	0
Egress Code Violation	18	0
Errored Seconds	2	0
Severely Errored Seconds	0	0
Unavailable Seconds	0	0

If there's anything else we can help with let us know