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Fibre speed drop after power cut

First Timer
Message 4 of 4

At the end of last week we had a power cut which lasted for about ten minutes. Since then my fibre sync speed is about 20 megs lower than it was before. Prior to this the line has been stable for over two years. I've tried rebooting the router, but it has not made any difference. Anyone from TalkTalk able to help? Thanks Kevin.


Whizz Kid
Message 1 of 4

I have seen a dramatic drop in MEASURED dowload speed many many times after power cuts, the latest being in the small hours today. During this winter our electric network seem to have a new way of working where they rapidly switch off small areas for a very short time to locate a fault so we have had dozens of cuts.


I am on 38mbs super fibre but usally now get around 26- 28 mbs MEASured dowload spped  and the router reports VDSL link rate of 28 to 30 mbs with occasional dropouts.. Some time ago I used to get faster MEASURED download of 31 to 33 mbs and no dropouts. I complained about the degradation so. BT OpenReach tested the line and identified an "anomaly" about 13 metres from my socket but declared the line within specification. So I have to live with my current performance. Whether that thas anything to do with what I am abouit to describe I know not.


This is my interpretation of what happens with my router (Super Router, D-Link version) with a power cut.


When power fails in an area everything is switched off apart from a few things with  batteries. When the power comes back much of the equipment will stay off so the immediate power demand is low. Every piece of electrical equipment produces electrical noise so with most off, the overall electrical noise is much lower. The super router comes on instantly and reconnects in about a minute  during the time when the electrical noise is low. Thus, the super router tries to connect faster. You can check this by looking at what it reports for the VDSL link speed. As I said above my usual reported speed is 28 to 30 mbs but this morning it reported 34 mbs but my MEASURED download speed (using was erratic and around 5mbs. I rebooted the router and VDSL link speed dropped to 28mbs but my measured download speed jumped to 26mbs.


I first saw this effect years ago on a much older router but back in the days when we had few power cuts so it was hardly worth mentioning. Now in these better and more enlightened times (us oldies still do sarcasm) it has become obvious that others who do not have the time to investigate like me, might benefit from my experience.


Message 2 of 4

Thanks for the info. The connection dropped briefly this morning and then reconnected around 8 Megs higher, so sounds like it's going in the right direction.


Insightful One
Message 3 of 4
Sounds like bts dlm kicked in and wrongly assumed that the line had a issue. Unfortunately talktalk have no control over fibre dlm you will have to be patient