internet disconnecting

[Orange]

my services were activated on 8th march.

My internet recently reconnected with a higher upload speed and download speed with a snr margin of 1.5 db for download, and 4.2db for upload.

This morning it has disconnected and  has decided to bring my snr margin back up to 3d and 6db on upload speed giving me slower upload speed.

Why does this change happen? I leave the router alone, it finds a faster speed, then changes it to a lower speed for some reason?

AM I going to see it reconnect itself again in a few days and see the snr margin lower again and then for it too reconnect again few days later because it doesn't like the lower snr margin? seems like their could be a fault? and that it will just keep reconnecting everytime the snr margins are lower?

[Chrisee · Accepted solution]

@Orange your VDSL connection is continually monitored by the Digital Line Monitoring system running in the cabinet your line goes to. That counts line errors and disconnections if these go outside pre-programmed limits in the previous 24 hours the system resets parameters like the noise margin in the early morning hours. Very few lines will be stable with noise margins below 3dB which is why your line was reset. Normally the system settles at a value after a couple of weeks my old VDSL service did not change for years but it was underground, lines on poles are often affected by bad weather. 

Beyond resetting the system neither Openreach or Sky can control the operation of the DLM. However note you resetting your hub too frequantly is seen by the system as a line drop so if you do that too frequently it will cause the connection to be slowed.

[Orange]

right so what you are saying is DLM will eventually keep my noise margin at a value that it likes.

Because if it keeps reconnecting after increasing its speeds im have to walk away from sky

[Orange]

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@Chrisee wrote:

@Orange your VDSL connection is continually monitored by the Digital Line Monitoring system running in the cabinet your line goes to. That counts line errors and disconnections if these go outside pre-programmed limits in the previous 24 hours the system resets parameters like the noise margin in the early morning hours. Very few lines will be stable with noise margins below 3dB which is why your line was reset. Normally the system settles at a value after a couple of weeks my old VDSL service did not change for years but it was underground, lines on poles are often affected by bad weather. 

Beyond resetting the system neither Openreach or Sky can control the operation of the DLM. However note you resetting your hub too frequantly is seen by the system as a line drop so if you do that too frequently it will cause the connection to be slowed.

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when you say your line diden't change for years do you mean it was fixed at a snr margin that the DLM preferred? Or did it keep disconnecting trying to make the speeds faster for you?

I have left my router connected since day 1

[Giggsy1977]

DLM will keep the line at a speed that provides a stable signal. 

Changing provider (unless you go to Virgin or FTTP is available) will have you using the same technology and line so you likely wouldn't see much difference. 

[Orange]

Virgin media doesn't use any form of error correcting?

[Chrisee]

@Orange as @Giggsy1977 points out this is how Openreach deliver VDSL services so if you switch to any other provider using the same line the system is still there. Most lines stabilise BUT the system is always running so if conditions change and errors increase it will kick in. Sky have a policy of not accepting speed complaints in the first 14 days of a connection as the system is still likely to be optimising.  

Openreach often only accept faults where the DLM system cannot stabilise the line without dropping the speed below the guaranteed minimum set for your line. That often will where the noise margin is around 8 to 9dB. Values below 3dB are rarely held for long but the range 3 to 6dB is considered as normal.