Dropping line sync speed

[#1]

My FTTC line sync is normally around 73Mbps, seems stable to use and generally get a good throughput in the 60s Mbps.

Sometimes though, the speeds drop due presumably to some change in line conditions, but I'm not sure what the problem might be? Here is a 7 day graph from my router showing actual sync speed and "max sync speed", along with the noise margin - you can see DLM resyncing the line at progressively lower speeds over the week, then at some point it will go back up. Synced at 68.523 right now but probably be back to 72/73 next week. Is this just normal or am I on dodgy copper?

[#2]

Hi @daveaspy, thanks for reaching out over the forums and I hope you're having a lovely bank holiday weekend  

Your line test I've ran is coming back ok, the stability is a little off so I'm sending off an order just to make sure that broadband is on the best settings essentially. This will take effect within 3 working days, check back then and see if this has improved things for you. 

[#3]

thanks for looking Curtis, it was curiosity I had about the line rather than needing anything done at the moment. The ticket seems to have been closed with "We're pleased to confirm that according to the information we have, we believe your broadband speeds are faster than the Minimum Guaranteed Speed of 54.6Mbps we promised you."

[#4]

@daveaspy 

JOOI, what software did you use to generate that graph, and do you use a Plusnet Hub?

[#5]

I have a tp-link router. The graphs come from a node-red dashboard that scrapes the line data from the router web interface every 30 second (ish, can't remember the exact time)

[#6]

Has the connection been better since Curtis placed the order to make the line more stable? 

[#7]

It's still dropping actually - resynced at 5am to 65.941. Updated graph below, I'm away for a few days after tomorrow so it's not a big issue right now, hopefully it will have recovered by the time I get back

BT Wholesale speed tests (over ethernet direct into the router) returning between 49-54Mbps (which is below the "Minimum Guaranteed Speed of 54.6Mbps we promised you"), and the results of the BT advanced test is below

[#8]

Hi @daveaspy how have things been for you over this past week or so?

[#9]

It has dropped a bit further, now synced at 65063 which is over 10Mbps lower than I have seen at its highest - I haven't seen it reconnect this week other than due to the electricity going off for a while.

I get between 50-54 Mbps download speed where I have previously seen high 60s.

[#10]

Cheers for getting back to me, when have you noticed the drops roughly? We're only seeing the one in the past 4 days at approximately 14:40 yesterday.

[#11]

I'm not sure now, possibly end of last week but with our full power outage yesterday I have lost the router logs and graphs. I don't think it has dropped on its own since I got back from my trip on Monday so it might not drop again now.

What does concern me a bit is that if the cause of the line instability goes away will my speed rise back to what it used to be? I don't know if you have capped the speed or raised the acceptable SNR. I wasn't actually complaining about this situation, just speculating as to the cause!