Partial LLU (CPW) SNRM question

An interesting thing happened this morning after a power cut: the router (tg585v7) resync'd and reported this xDSL linestate up (ITU-T G.992.5; downstream: 14657 kbit/s, upstream: 1022 kbit/s; output Power Down: 19.5 dBm, Up: 12.0 dBm; line Attenuation Down: 37.5 dB, Up: 21.5 dB; snr Margin Down: 6.5 dB, Up: 9.0 dB)

Then a while later these are the stats:

Uptime: 0 days, 3:56:58
DSL Type: G.992.5 annex A
Bandwidth (Up/Down) [kbps/kbps]: 1.022 / 14.657
Data Transferred (Sent/Received) [kB/kB]: 0,00 / 0,00
Output Power (Up/Down) [dBm]: 12,0 / 19,5
Line Attenuation (Up/Down) [dB]: 21,5 / 37,5
SN Margin (Up/Down) [dB]: 10,0 / 2,5
Vendor ID (Local/Remote): TMMB / BDCM
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 11 / 0
FEC Errors (Up/Down): 0 / 1.846.664
CRC Errors (Up/Down): 0 / 875
HEC Errors (Up/Down): 96 / 532

Note the downstream SNRM has changed to 2.5dB and upstream to 10dB.

Normally on my adsl2+ (xilo/uno) interleaved connection downstream attenuation is 37dB, sync ~13Mbps with a SNRM of 5.5dB or 6dB, also FEC Errors are usually 500.000 per 24 Hours

Seems rather odd, probably wont last, also downstream throughput is much faster than normal at 12165Kbps - usually ~11000Kbps.

It will be interesting to see how long I can hold these speeds and whether the connection is dropped tonight when the SNRM usually becomes less?

What time did it sync?

In reply to a post by RobertoS:

What time did it sync?

At about 9.55am

Connection is still holding at 6pm, SNRM's are now 10.5db up and 3dB down, down FEC Errors are now 2.578.116 !!!

Sounds from those FEC rates that it isn't at all comfortable. I doubt if they are slowing the throughput much though. It was when they got to a few thousand per second I found they did.

@ 8.50pm

Uptime: 0 days, 9:38:00
Bandwidth (Up/Down) [kbps/kbps]: 1.022 / 14.657
Output Power (Up/Down) [dBm]: 12,0 / 19,5
Line Attenuation (Up/Down) [dB]: 21,5 / 37,5
SN Margin (Up/Down) [dB]: 10,5 / 3,0
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 15 / 0
FEC Errors (Up/Down): 0 / 3.239.541
CRC Errors (Up/Down): 0 / 1.728
HEC Errors (Up/Down): 96 / 1.269

Never had this happen before during the nearly 7 months with the uno SMPF connection - usually after a resync downstream SNRM is a steady and stable 6dB. For some reason this time, following a power cut, the router log reported a downstream SNRM of 6.5dB and a few hours later, after I booted the pc and then checked the router stats, the SNRM was showing as 2.5dB.

I wonder if something has had it's power supply goosed by the power cut, and as a result it's now kicking out REIN ?

Can you power off EVERYTHING else in your house, except our router and PC, power cycle the router, and check the stats again, especially see if the errors have cleared and stopped.

It's almost the opposite effect, as the sync is so high. Negative noise at sync time? That'd be interesting. The high speed will automatically increase the error rate.

In reply to a post by Zarjaz:

I wonder if something has had it's power supply goosed by the power cut, and as a result it's now kicking out REIN ?

Can you power off EVERYTHING else in your house, except our router and PC, power cycle the router, and check the stats again, especially see if the errors have cleared and stopped.

Cheers - will try that tomorrow morning if the connection holds overnight or even if it does resync again overnight with a similar downstream SNRM and error rate

BTW. router, computer and all peripherals are all surge protected but other appliances in the house are not.

That tg585v7 is doing well - it's still holding on with a downstream SNRM of 2.5dB with an FEC Error count of 4.047.158 after more than 12 hours - it's now nearly 11.30pm

Connection is still holding with a downstream SNRM of 3dB after nearly 27 hours, FEC Errors are 6.142.667 - I feel inclined to leave it a little longer, just out of interest, to see how it goes...