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Guru
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Message 11 of 42

Re: Noise Margin Reduced.

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Impulse noise is often at its highest during nightime hours (02.00am) often due to environmental radiation from street lighting, international radio/tv wave frequencies bounced off the ionosphere etc. ... therefore margins deplete at night, therefore a reboot at night on a depleted margin will give a slightly depleted sync rate. Don't get SNR confused with SNRm, two different things. It's why only stable connections that lose less margin ... and associated DLM (non)reaction will get to use a 3db noise margin, and why they're deemed "green" in the first place. It's the same reason a daytime re-sync in daylight will always give a better sync rate when margins have recovered.
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Message 12 of 42

Re: Noise Margin Reduced.

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@RogerB wrote:
Impulse noise is often at its highest during nightime hours (02.00am) often due to environmental radiation from street lighting, international radio/tv wave frequencies bounced off the ionosphere etc. ... therefore margins deplete at night, therefore a reboot at night on a depleted margin will give a slightly depleted sync rate. Don't get SNR confused with SNRm, two different things. It's why only stable connections that lose less margin ... and associated DLM (non)reaction will get to use a 3db noise margin, and why they're deemed "green" in the first place. It's the same reason a daytime re-sync in daylight will always give a better sync rate when margins have recovered.

Thanks. I agree with your comment re impulse noise.

Industrial systems used to be required to be immune to short bursts, up to a given length of (very short) time, and were designed to comply with a spec. Also a lot of work went into power supply design, where some, but not all of the interference came through.

More difficult for a large telephone network, but instinct says that the HH6 power supply is robust,

 

I'm not too bothered  about +0.4db increase in margin, and it's results! It gives a safety margin.

It's still puzzling why I achieved 58mbs downstream until a local mains supply failure in Nov 2015 , at a 6db noise margin.

It seemed to reclassify the line quality to the lower levels, where the acceptably declared speeds reduced ( impacted?).

Was on "interleaved" in those days, and have been on "fastpath" since installing the HH6.

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Storm_Force
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Message 13 of 42

Re: Noise Margin Reduced.

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Just check mine noise margin is now 1.2 ? and now sync'd around 5mb higher on download.

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Distinguished Sage
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Message 14 of 42

Re: Noise Margin Reduced.

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Likely a dslam reset over night and you were one of the first to resync.
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Distinguished Sage
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Message 15 of 42

Re: Noise Margin Reduced.

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Looks like I was 3dB'd (actually 4.8dB in my case as I have headroom on Infinity1) last night. Now syncing at max up and down for Infinity1 with attainable 57/13

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Message 16 of 42

Re: Noise Margin Reduced.

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@licquorice wrote:

Looks like I was 3dB'd (actually 4.8dB in my case as I have headroom on Infinity1) last night. Now syncing at max up and down for Infinity1 with attainable 57/13


Smiley LOL

Just wait until the hub reboots at odd times, thats if you are using a HH6.

Mine rebooted 2 days ago, presumably due to ipv6 being temporarily disabled.

Noise margin is now sitting at 1.4db.

It's good for download speed, though, which is increased to 62mbps down - becoming nearer to the declared max speeds.

Wonder how long it will take to trip.

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Guru
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Message 17 of 42

Re: Noise Margin Reduced.

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@Ribblelancs wrote:

@licquorice wrote:

Looks like I was 3dB'd (actually 4.8dB in my case as I have headroom on Infinity1) last night. Now syncing at max up and down for Infinity1 with attainable 57/13


Smiley LOL

Just wait until the hub reboots at odd times, thats if you are using a HH6.

Mine rebooted 2 days ago, presumably due to ipv6 being temporarily disabled.

Noise margin is now sitting at 1.4db.

It's good for download speed, though, which is increased to 62mbps down - becoming nearer to the declared max speeds.

Wonder how long it will take to trip.


Probably until it meets its first breach of errored seconds count at 1440 = 24 total minutes of non recoverable errors in 24 hours
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Message 18 of 42

Re: Noise Margin Reduced.

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@RogerB wrote:

@Ribblelancs wrote:

@licquorice wrote:

Looks like I was 3dB'd (actually 4.8dB in my case as I have headroom on Infinity1) last night. Now syncing at max up and down for Infinity1 with attainable 57/13


Smiley LOL

Just wait until the hub reboots at odd times, thats if you are using a HH6.

Mine rebooted 2 days ago, presumably due to ipv6 being temporarily disabled.

Noise margin is now sitting at 1.4db.

It's good for download speed, though, which is increased to 62mbps down - becoming nearer to the declared max speeds.

Wonder how long it will take to trip.


Probably until it meets its first breach of errored seconds count at 1440 = 24 total minutes of non recoverable errors in 24 hours

Thanks.

The cabled run from the cabinet runs through the main street of a "larger" village (will soon be much larger!), so some noise could be expected.

It's held for 2 days.

All our cables are underground, with a few exceptions.

Present conditions:- very wet, heavy rain.

This shows how Openreach have improved the structure in the past few years. They have been busy in the streets over the past year.

 

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Guru
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Message 19 of 42

Re: Noise Margin Reduced.

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Underground ducting for cables is far better than overhead external cables as they don't fall into the environmental impulse noise gap as such ... but even then what becomes more difficult to handle is any crosstalk in the bundles. And why after much expense on same ... BT have implemented G.INP (Phyr technology). Which presently is only running downstream.
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DavidCo
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Message 20 of 42

Re: Noise Margin Reduced.

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Has anyone an idea of the timescale of this 'rollout'

 

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