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Standard User WelshWArrior
(fountain of knowledge) Tue 14-Feb-17 10:56:51
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SNR Trial expanded?


[link to this post]
 
Just had the following email to say my line experienced a dropout at 10am this morning:

Reason: 1 Remote Defect Indicator/DLM

Current Downstream Sync Rate is now 78985kbps @ 3.9db SNRM
Current Upstream Sync Rate is now 20000kbps @ 5.2db SNRM

Haven't got access to my modem at moment as I'm in work but my DSLStats username is Tenbyboy2 if anyone has access and can see more details.

Just logged on remotely and did a speedtest via btwholesale and got the following results so something isn't right:

Download speedachieved during the test was - 19.62 Mbps
For your connection, the acceptable range of speedsis 60 Mbps-76.37 Mbps .
Additional Information:
IP Profile for your line is - 76.37 Mbps

Just wondering if this is possibly an expansion of the 3db SNR trial??

I'll tray and get my full modem stats asap.

Edit: Managed to get the stats but no time to format sorry:

Mode VDSL2
Traffic Type PTM
Status Up
Link Power State L0
Downstream Upstream
Line Coding (Trellis) On On
SNR Margin (dB) 1.8 4.6
Attenuation (dB) 18.7 0.0
Output Power (dBm) 12.6 7.4
Attainable Rate (Kbps) 65279 19323
Rate (Kbps) 78985 20000
B (# of bytes in Mux Data Frame) 243 237
M (# of Mux Data Frames in an RS codeword) 1 1
T (# of Mux Data Frames in an OH sub-frame) 0 45
R (# of redundancy bytes in the RS codeword) 10 16
S (# of data symbols over which the RS code word spans) 0.0984 0.3782
L (# of bits transmitted in each data symbol) 20657 5373
D (interleaver depth) 8 1
I (interleaver block size in bytes) 254 127
N (RS codeword size) 254 254
Delay (msec) 0 0
INP (DMT symbol) 48.00 0.00
OH Frames 0 0
OH Frame Errors 1187 151
RS Words 64889264 4068912
RS Correctable Errors 842080 44
RS Uncorrectable Errors 0 0
HEC Errors 0 0
OCD Errors 0 0
LCD Errors 0 0
Total Cells 241180887 0
Data Cells 8399660 0
Bit Errors 0 0
Total ES 76 109
Total SES 21 0
Total UAS 391 380

-------------------------------------------
BT Infinity 2 Unlimited
http://www.thinkbroadband.com/speedtest/button/14676...

Edited by WelshWArrior (Tue 14-Feb-17 10:59:15)

Standard User WilliamGrimsley
(member) Tue 14-Feb-17 10:58:49
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Re: SNR Trial expanded?


[re: WelshWArrior] [link to this post]
 
Yes, but your line is not happy. It seems like the line resynced twice and didn't go too well as the current downstream SNR margin was dropped way below the target of 3 dB. I'd keep monitoring, but line protection is having to significantly work harder (like my line) and several downstream CRC's are getting through.

Edited by WilliamGrimsley (Tue 14-Feb-17 11:27:46)

Standard User BatBoy
(sensei) Tue 14-Feb-17 11:48:35
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Re: SNR Trial expanded?


[re: WelshWArrior] [link to this post]
 
Yes that looks like what happened to my line too. I see your g.inp ratio of 76.37/78.95=0.9669 is correct too, just like mine wink

So it looks like you've been set to a 4dB target margin.


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Standard User j0hn83
(member) Tue 14-Feb-17 11:53:38
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Re: SNR Trial expanded?


[re: WelshWArrior] [link to this post]
 
Had a look at your line on MDWS. Looks to me like the DSLAM rebooted. You resynced much might than usual, but as everyone else connected to the cabinet your snrm has crashed, both up and down. The attainable is also way below sync. Definitely not part of the trial, it's actually a very common occurrence.
Standard User j0hn83
(member) Tue 14-Feb-17 11:54:45
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Re: SNR Trial expanded?


[re: BatBoy] [link to this post]
 
In reply to a post by BatBoy:
Yes that looks like what happened to my line too. I see your g.inp ratio of 76.37/78.95=0.9669 is correct too, just like mine wink

So it looks like you've been set to a 4dB target margin.
Never in a million years. Look at his line on MyDSLWebStats.
Standard User WWWombat
(knowledge is power) Tue 14-Feb-17 14:32:41
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Re: SNR Trial expanded?


[re: j0hn83] [link to this post]
 
In reply to a post by j0hn83:
Had a look at your line on MDWS. Looks to me like the DSLAM rebooted. You resynced much might than usual, but as everyone else connected to the cabinet your snrm has crashed, both up and down. The attainable is also way below sync. Definitely not part of the trial, it's actually a very common occurrence.


I agree.

When you zoom into the SNRM graph, you can see it was a 7 minute outage, not 1 minute.

You can also see that SNRM (up and down) starts at 6dB, then drops to 4dB for 3 minutes, then drops to 3dB, then 2dB, where it stays.

Things have subsequently returned to speeds approaching the norm.
Standard User WilliamGrimsley
(member) Tue 14-Feb-17 14:51:29
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Re: SNR Trial expanded?


[re: WWWombat] [link to this post]
 
Stupid me, didn't think of a power outage.
Standard User WelshWArrior
(fountain of knowledge) Tue 14-Feb-17 15:18:58
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Re: SNR Trial expanded?


[re: WWWombat] [link to this post]
 
I just went past and spoke to one of the Openreach Engineers that are working on the cabs again - there's 4 huge Openreach vans there and several tents covering both cabs and 2 of the manholes in front of the cabs.

Apparently, they are running more fibre to do with roundabout they are building right by there. Whatever they've been doing the past few weeks, my attenuation is dropping a little so it's not all bad smile

-------------------------------------------
BT Infinity 2 Unlimited
http://www.thinkbroadband.com/speedtest/button/14676...
Standard User lee111s
(experienced) Tue 14-Feb-17 15:23:36
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Re: SNR Trial expanded?


[re: WelshWArrior] [link to this post]
 
Pretty sure witchunt confirmed that a few days ago.
Standard User WelshWArrior
(fountain of knowledge) Tue 14-Feb-17 15:34:51
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Re: SNR Trial expanded?


[re: lee111s] [link to this post]
 
He did indeed but that was a separate job that they had finished and now this is a new one that is going to take a few more days now apparently.

-------------------------------------------
BT Infinity 2 Unlimited
http://www.thinkbroadband.com/speedtest/button/14676...
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