Cab upgrade has resulted in BT IP Profile to drop

Our local cabinet has been upgraded (or replaced) - all the lines locally were disconnected for 2 days. My line is now working again but my BT IP profile has dropped
from a stable 59.84 - 44.18 Mbps.

I'm with Plusnet, who have said that my speed may 'pick up' - e.g. back to 59.84 where it was for the last two months, however I'm doubtful.

Would you advise me to raise a fault to get the profile reset by Openreach?

I would give it a couple of days and then raise a fault with Plusnet, who hopefully will get an Openreach engineer to come out, who should plug various things into your line and, if it all checks out, call Openreach to get it reset.

Has your latency/ping gone up by around 8-10ms as well?

Yes it's increased from around 16ms to now 23ms

Your line has changed from "Fast Path" to "Interleaved". Those two things taken together are the indicators.

It may self-adjust back in a few days if you don't mess with the connection - just use it normally. If it doesn't after a couple of weeks then you need to ask Plusnet if they can get it reset.

The chances of the latter are rather remote - which isn't Plusnet's fault. It basically only gets done if the right sort of engineer on a fault call requests it from the the Openreach control centre. As far as BT Wholesale and Openreach are concerned you don't have a fault so Plusnet's reporting of it would be rejected. They would be told the DLM is just doing its job.

Thanks. I've already raised a fault with Plusnet, so you think it's likely it will be rejected. I do hope you're wrong!

The speed dropped by 20Mbps in two days after one of the two cabinet's was replaced. So one would think that they should 'fix' my connection back to where is was.

I presume you mean, don't reboot the modem - don't worry I won't touch it - thanks.

It all depends on what has caused your speed to drop...

A drop from 59Mbps to 45Mbps is a loss of 24% bandwidth, which is at the high end of what could be explained by DLM turning on interleaving. As already mentioned, an increase of 8ms latency is also an indicator of DLM intervention.

So... prime suspicion is that you have suffered a large intervention from DLM - turning on a high level of interleaving and FEC. These add latency and steal bandwidth in order to reduce errors.

The question is... why?

If there is a real physical line problem (such as a fault in a crimped connection in the new cabinet) and it has caused the sync speed to drop, then that is a thing for Openreach to investigate and perhaps fix. DLM will probably have intervened, and there is no point in resetting it until the line problem is fixed.

On the other hand, if the replacement of the cabinet has induced lots of errors onto the line, but not actually caused a physical problems to the line itself, then you may be suffering because DLM has intervened in an attempt to eradicate those errors. DLM will reset itself within 2-4 weeks - and there is nothing that Plusnet alone can do to get it reset. A reset can only be requested by an Openreach engineer attending a fault - and even they can't always get the Openreach operations centre to perform the reset!

On the third hand, it might be a problem that has nothing to do with replacement of the cabinet, and you are suffering from crosstalk from a new FTTC customer which is interfering with your line - suspicious timing, but also a possibility. DLM may be playing a part here too, but a reset in this case wouldn't achieve anything. DLM would turn back on again within 48 hours, and intervene again.

The second of the three cases is the most likely, and the easiest way to check is to wait those 2-4 weeks. Even if Plusnet want Openreach to attend, I bet that Openreach themselves would want to wait a while.

Which cabinet was changed? FTTC or the PCP wiring cabinet?

And what was your original estimated speed?

In reply to a post by shalom2005:

I presume you mean, don't reboot the modem - don't worry I won't touch it - thanks.

Ah, yes and no!

If you haven't done that since it slowed down, I recommend you do turn it off for half a minute or so during daylight hours, and see how things are afterwards. Probably no different, and leave things alone afterwards unless something really bad results. A small chance things will be better, though not back up to what it was. That needs waiting for, as earlier, because of the interleaving.

WWWombat's post wasn't there when I started my previous one, and I've only just come back and seen it.

His is a much more comprehensive explanation than I gave of what may have happened .

Thanks for the replies. I've only just seen them myself. The router rebooted & I lost my connection for an hour!

The FTTC cab was not replaced but they replaced an old cabinet (I presume PCP wiring) with a new one. But as I said several hundred lines were disconnected (without any warning) for 2 days.

I have only rebooted the modem once & the BT IP Profile has remained at 37.5 (from 59.41),
I know you both said wait a few days/weeks but I raised the ticket before asking here. I'd like to try to get it fixed if there's a chance rather than wait. My previuos connection was solid with no dropped connections at all, so I know that it's all cabinet related. I'll give feedback what happens on this thread for others to read.

Hang on .

You say your IP profile is stuck at 37.5Mbps, but in your opening post you said:-

My line is now working again but my BT IP profile has dropped
from a stable 59.84 - 44.18 Mbps.

Yes - it dropeed again yesterday morning to 37.5 (still the same this morning)

Yours is a similar drop to the one I experienced a month or two back and Plusnet was happy to accept it as a fault and send out an Openreach engineer to reset the profile. I am back on a higher speed than I was before the drop and it has held now for nearly 6 weeks.

Kevin - what was the reason for the drop?

MIine as I said was after a two day cabinet fault/upgrade with no internet or phone for several hundred people locally!

In reply to a post by shalom2005:

Kevin - what was the reason for the drop?

It wasn't conclusive, but I had a line fault about a week earlier that knocked out the telephone but not the broadband for about 3 days. It seemed OK after this, but I went away for a weekend (leaving everything connected), during which the logs show the connection dropped completely for a few hours. When I got back my sync speed had gone down from around 66 Mbps to just over 40. A modem reboot got it back up to just over 60, but very shortly afterwards it went down to 39999/9997. So I raised a fault with Plusnet, who confirmed there was a fault and booked an engineer visit. In the meantime, sync changed to 38179/16997. The engineer (very pleasant) was here for some time, did various tests which confirmed the line was fine and he spent a long time on the phone to get the profile reset, which resulted in a sync of 71212/20000, which reduced to 68014/20000 after he unplugged and re-plugged the modem to do something, where it has remained ever since.

Thanks for that Kevin. I'll keep what you said in mind, but keep dreaming of anything over 66 (original synch). I just really want the line to return to where it was before OR messed about with the cab. So far, logged the question on Friday & at a status of "Awaiting support team answer" - due Monday.

Just a follow up to my previous post. Plusnet have kindly arranged an OR engineer to visit on Wednesday 17th, so hopefully a reset will be done (OR/BT had already made a note on their system that my speed has recently dropped & a fault has been is noted, hopefully that will go in my favour)

As a follow up if anyone is interested.

The cabinet that I thought was 'upgraded' had in fact been vandalised of copper!!!

After the OR visit my profile has now almost returned to normal at 58.08 Mbps, (with a possible reset which will take 24 hours to kick in.)

That was my suspicion - it could take a day or two for them to remake all the connections.

Now Openreach have reset your line, DLM will be starting again. It will monitor your line for the first two days, and watch the level of errors. If it decides to intervene to add interleaving, it will usually do so after 48 hours, and at some time between 2AM and 7AM.

Thanks I'll keep an eye on it & will NOT touch the modem!

In reply to a post by shalom2005:

As a follow up if anyone is interested.

The cabinet that I thought was 'upgraded' had in fact been vandalised of copper!!!

After the OR visit my profile has now almost returned to normal at 58.08 Mbps, (with a possible reset which will take 24 hours to kick in.)

I know metal prices are high but really how much copper realistically can you get out of a single cabinet? £20?

It seems that criminals get stupider and stupider.

Wrong!!!

The OR guy said the cost was around 30K - it was the underground cable as well & the thieves used an OR van

Cost to replace will be a lot MORE than the scrap value.

A quick peek suggests £30,000 scrap copper would be some 7,500 kilo (or 16,000 lb in old money)

Oh - well that's what I was told

In reply to a post by undecidedadrian:

In reply to a post by shalom2005:

As a follow up if anyone is interested.

The cabinet that I thought was 'upgraded' had in fact been vandalised of copper!!!

After the OR visit my profile has now almost returned to normal at 58.08 Mbps, (with a possible reset which will take 24 hours to kick in.)

I know metal prices are high but really how much copper realistically can you get out of a single cabinet? £20?

It seems that criminals get stupider and stupider.

could be someone wanting to force a new lot of copper in their cabinet due to dodgy dsl performance?

In reply to a post by Chrysalis:

could be someone wanting to force a new lot of copper in their cabinet due to dodgy dsl performance?

The thought briefly crossed my mind, but I bet the cause of my slow connection is underground joints, so demolishing my PCP probably wouldn't achieve anything.