Cable Forum - 1000M 5th Upstream

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- - 1000M : 5th Upstream (https://www.cableforum.uk/board/showthread.php?t=33711389)

Paul	06-11-2023 18:49

Re: 5th Upstream

I have 5 Upstream channels listed under 3.0, I have a 6th upstream channel listed under 3.1.

Downstream I appear to have 31 channels listed under 3.0, and 1 listed under 3.1 (with 208 Uncorrectable errors).

On another page, DOCSIS Mode is listed as 3.1

Martin_D

07-11-2023 10:16

Re: 5th Upstream

Quote:

Originally Posted by Sephiroth (Post 36163460)

It's not normal. What I'm not sure about is whether the 417K uncorrectables you have are entirely down to your data. Your modem "sees" everything on your segment. The modem filters on a unique security key and that data proceeds past that gate and onto your router.

I thought it was normal on the 3.1 side of things sorry for posting misleading info

Sephiroth

07-11-2023 10:28

Re: 5th Upstream

Quote:

Originally Posted by Martin_D (Post 36163549)

I thought it was normal on the 3.1 side of things sorry for posting misleading info

No worries. You can't be expected to know what you don't know!

SnoopZ

07-11-2023 16:47

Re: 5th Upstream

Quote:

Originally Posted by Sephiroth (Post 36163551)

No worries. You can't be expected to know what you don't know!

Is there a minimum and maximum PLC Power (dBmV) spec for a 3.1 downstream channel as mine shows as -2.0?

Sephiroth

07-11-2023 19:52

Re: 5th Upstream

The power level range for d3.1 is the same as it was for D3.0. That is because at the symbol level, its just a collection binary bits out of which the modem has to make sense.

The official (CableLabs) range is -15dBmv t0 +15dBm. That is the range within which the modem will try and make sense of what it is receiving. The practical range is c. -7dBmv through +15dbMv. Sometimes the higher power level (above 10dBmv) can be problematical if there is considerable noise that gets amplified by that high power.

-2dBmv is fine. D3.1 downstream can operate in a frequency range of 252 MHz to 1788MHz (D3.0 is constrained to 1002MHz at the high end). In practice, VM use a frequency above 690MHz which will attenuate the power transmitted by the last active node (c. 44 dBmv iIrc).

A good technical read at: https://www.commscope.com/globalasse...-docsis-wp.pdf

Chrysalis

11-11-2023 10:08

Re: 5th Upstream

376 million corrected errors now, with no reboot since my last update in this thread.

Also interestingly I used to get on old firmware semi regular T3 timeouts on the 3.1 US and not a single one since the new firmware was installed.

SnoopZ

11-11-2023 10:23

Re: 5th Upstream

I seem to have less collectables since I last reset and posted the number on 5/11 1,164,395,478 and my uncorrectable errors are currently at 910209.

Sephiroth

11-11-2023 12:05

Re: 5th Upstream

Correctable don’t matter. Uncorrectable do if there are constantly rising. However, an very high and upwards moving correctable number is a sign of signal impairment that could lead to uncorrectable.

Broken Hope

13-11-2023 19:10

Re: 5th Upstream

Mine updated on the 1st and I'm at 4023 uncorrectable so low compared to what's being reported here.

Chrysalis

15-11-2023 15:04

Re: 5th Upstream

Had an outage during the night, a bunch of post RS errors on 3.0 downstream channels, and 76 T3 timeouts on my 3.1 US channel.

All times are GMT +1. The time now is 14:47.

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