Speed drop all of a sudden?

[andrue]

So why is it just your connection?

Good question. I think it's something to do with the regrade I had. The speeds I'm currently getting are not far off what you'd get with 40/10. My theory is that the old 40/10 profile is still in BT's system and every two months it kicks in and tries to retrain my line for four or five days.

It may also be that others just aren't noticing it - after all 25Mb/s is still a fair whack and not everyone is an anal about speed tests as me.

[Bald_Eagle1]

Very strange.

So, this ALWAYS happens on 19th of every other month & a simple ROUTER reboot ALWAYS restores normal throughput speeds?

It doesn't seem like account throttling due to excessive downloading as a ROUTER reboot wouldn't cure that.

Assuming your ongoing stats don't show any drops in SNRM levels, sync speeds, attainable rates, increased error counts etc. or any other 'strangeness' we can rule out the actual VDSL connection.

19th is the date your account was activated?
I don't know if my ISP, Plusnet still do it, but occasionally heavy users had their speeds restricted until the next billing date.
Is this a slight possiblility?
Again though, a router reboot shouldn't clear that.

There is nothing between you & the cabinet that could cause 'interference' every other month?
Even if there was, a router reboot surely wouldn't clear it up.

It must be worth a shot, with the evidence you now possess, to request that the ISP deletes your account & creates a new one, (with no new contract period) if only to eliminate a spurious reversion to a lower profile, maybe due to account corruption.

If that could be implemented, at least you would have some peace of mind that any account corruption can be ignored if it should ever happen again.

If it was a network issue, surely other users would see similar symptoms.

Are you able to try a different router around 19th of future months, just in case the router stores up some 'problems' that coincidentally surface 19th of every other month?

Have you previously mentioned that the problem still occurs if bypassing the router & using a direct connection to the modem?

[Simon]

I don't know if my ISP, Plusnet still do it, but occasionally heavy users had their speeds restricted until the next billing date.
Is this a slight possiblility?

As far as we know, IDNet have never restricted 'heavy' users - if they go over their download allowance, they are simply charged the extra, at £1 per Gb.

[Bald_Eagle1]

It may also be that others just aren't noticing it - after all 25Mb/s is still a fair whack and not everyone is an anal about speed tests as me.

Final thought, then I'm out of ideas:-

Are you using a BT Home Hub?

I believe that BT withdrew/replaced some models of a particular version due to a similar problem in that the router had to be rebooted every so often due to reduced throughput speeds.
I don't know if the timing pattern was as regular as yours though.

Does it ever vary by a day or so, depending on whether there are 30 or 31 days in the month?

As I'm not with BT & don't use a Home Hub I didn't pay too much attention to which model was mentioned.

[andrue]

Very strange.

So, this ALWAYS happens on 19th of every other month & a simple ROUTER reboot ALWAYS restores normal throughput speeds?

Yup. You can tell from the dates of my postings in this thread.

It doesn't seem like account throttling due to excessive downloading as a ROUTER reboot wouldn't cure that.

That would be unlikely anyway. I'm not a heavy user. In December I did manage to clock up 60GB but that was because I was downloading test data for work (our office connection is bad, though I'm running a project to upgrade it to a leased line). My typical month is about 10GB, rarely more than 20GB.

is the date your account was activated?

No, that was the April 16th but isn't there supposed to be a three day trial period? My TBBQM graphs of April 2012 (no longer accessible) showed a latency change on the 19th at exactly the same hour as when my connection first went live.

There is nothing between you & the cabinet that could cause 'interference' every other month?
Even if there was, a router reboot surely wouldn't clear it up.

I doubt it. It's a housing estate on the edge of a small rural town:

http://maps.google.co.uk/maps?f=q&source=s_q&hl=en&geocode=&q=nn136ja&aq=&sll=51.528642,-0.101599&sspn=0.704844,1.198883&vpsrc=6&t=h&ie=UTF8&hq=&hnear=Brackley+NN13+6JA,+United+Kingdom&ll=52.031603,-1.161348&spn=0.001361,0.002342&z=19

From the roundabout bottom right to top left via Pavillons Way.

It must be worth a shot, with the evidence you now possess, to request that the ISP deletes your account & creates a new one, (with no new contract period) if only to eliminate a spurious reversion to a lower profile, maybe due to account corruption.

I might try that actually. I'll see what they say in response to my email. As usual I have no idea if they got the email though because there's been no acknowledgement :-/

If it was a network issue, surely other users would see similar symptoms.

I would have thought so yes - although if you broaden 'network issue' to include misconfiguration it might be fewer people.

Have you previously mentioned that the problem still occurs if bypassing the router & using a direct connection to the modem?

Yeah, tried that - no change :-/

Compared to what Niall is going through it's a fairly trivial problem. Especially since I know it'll be over sometime on the 24th. But I'm a software engineer and it bugs me that no-one knows (and worse even cares). A reliably reproducible fault is something that any engineer should leap at. 

[andrue]

Are you using a BT Home Hub?

Nope. A Netgear WNR1000v3. The same one IDNet supply but bought for myself as it was cheaper.

Does it ever vary by a day or so, depending on whether there are 30 or 31 days in the month?

Wow! You're right - I hadn't really noticed that before:

December - 20th


October - 20th (I was at wedding so can only go by the increase in latency).


And the latency always starts in the late afternoon. Yesterday it started at 3pm which is the same as December although October looks to have been 4pm. OMG. British Summer Time. So we can say that it always starts at 1500utc. Now what's the repeat interval. 60 days?

August and June graphs are not available any more but I clearly noticed it on the 19th of previous months and it was the 19th of this month.

[Bald_Eagle1]

Nope. A Netgear WNR1000v3. The same one IDNet supply but bought for myself as it was cheaper.

Same as mine, supplied by Plusnet.
I don't have this issue though.

I did read of some Plusnet users updating the router's firmware & having problems, so reverted to the firmware version as originally supplied.
When I get chance later on, I'll try to track down what the issue was.

Have you updated the firmware version in your router?

This is from my router:-
Firmware Version V1.0.2.30_53.0.66B1
GUI Language Version V1.0.2.30_2.1.10.1


"Interesting" thing with the dates/BST times pattern.
I wonder what the relevance could be.
The only setting I can find that MAY have some effect is the timeout option.
Mine is set to 0 - i.e. permanently ON 24/7.

[Glenn]

60 days is a 1440 hour cycle, if that helps.

[andrue]

60 days is a 1440 hour cycle, if that helps.

Hmm. I just had an interesting and informative chat with Support. They'd already noticed that there was increased latency on my line even though very little traffic. They are in contact with BT to try and get some more info but of course it's anyone's guess how long it will take for a response. Overall he agrees that it's odd but it seems to be a combination of issues - to an extent it looks like a DLM issue except that I can show that my modem has been connected all through. He did explain though that the DLM is more a of a law unto itself with FTTC than with ADSL so it's conceivable it could change things even without a sync event.

Have you updated the firmware version in your router?

This is from my router:-
Firmware Version V1.0.2.30_53.0.66B1
GUI Language Version V1.0.2.30_2.1.10.1

Same as mine. I think it updated in November when I happened to log on to it.

"Interesting" thing with the dates/BST times pattern.
I wonder what the relevance could be.
The only setting I can find that MAY have some effect is the timeout option.
Mine is set to 0 - i.e. permanently ON 24/7.

Same here. Anyway even a direct connection has the problem so if it's the router it would have to be the router upsetting the DSLAM and putting it into a four day sulk rather than the router being prissy for four days

[mervl]

Resetting the account seems a good measure. But is it also possible for IDnet (or via ebay) to do a swap out of the modem, and router for good measure (I thought IDNet could loan at least a router for troubleshooting)?

I just mention this because the only time I've had something similar is once a few days after updating my modem/router firmware, when the line characteristics reported by the modem didn't change but latency and throughputs subsequently took a hammering spontaneously for a couple of days with more resyncs than I usually have in several months, then cleared of its own accord. (But the IP profile reported by the BT tester also took a hammering for the first time in my FTTC history). I'm thinking there might be some regular occurrence on the line in your case  - some sort of automated checking perhaps - to which the your modem or router takes an aversion, but which is not normal? As the line characteristics haven't changed it then returns to normal, but for some strange reason takes its time to do so. (Just thinking that as you had the issue on a direct PC connection, perhaps suggests the modem, but as no-one else has reported the same issue I guess I'm spouting rubbish but will post anyway!). The fascinating thing to me is the 3pm/4pm coincident with home-from-school "peak" start.

[andrue]

I have to thank Support this time around. They've been helpful and have raised it with BT. Unfortunately BT's response wasn't really very informative.

"Remote diagnostics have been carried out and currently all tests pass. No
over-utilisation of the cab is indicated. I have discussed the issues you
have stated (ie issues occur regualrly every 60). The FTTC network team
have stated no profile changes have taken place or any limitations on your
customer circuit.

Next course of action recommended/to be taken: As current remote checks do
not indicate any issue, if you require any further investigation and have
fully eliminated any possible cause of issues with your customer
equipment/set up/sources of interferance, in order to instigate an
Openreach engineer for further checks"

Unfortunately I don't think getting an engineer out is going to be sensible unless they know not to investigate the line itself. The latest graphs from Bald Eagle's monitoring show that there's nothing wrong there.



So I seem to have hit a brick wall at the moment 

[mervl]

Unfortunately I don't think getting an engineer out is going to be sensible unless they know not to investigate the line itself. The latest graphs from Bald Eagle's monitoring show that there's nothing wrong there.

I agree. Unfortunately at Ofcom's dicktat, BT has ring fenced divisions, and OR customer engineers only deal with the line between CPE and the original cab. I gather the DSLAMs and fibre cabs are the responsibility of network teams (BT Wholesale or possibly another division of OR?). But they seem to have responded too. But as a residential service without guaranteed service standards, what do you really expect for the lowest mandated price? Would we all be prepared to pay more so that you can get the level of consistent service you would like? Sorry. It's an occasional hiccup - it bugs you but that's life. There are more important things.

[andrue]

IDNet Support have done well. They got an engineer out yesterday but unfortunately he was only interested in the line and aside from confirming that it was a little bit noisy he said there was no problem. I showed him various graphs and stats and he agreed it was a problem but outside of his remit.

This morning I tried a temporary login and different IP address but the problem was still there. Unfortunately when I switched back to my correct login the problem had gone. Still - it's progress of a sort. We know that it's not specific to my login. I think it's pointing toward an issue with the cab and my port. Something in there is causing an increase in latency which has the knock-on affect of limiting my downstream throughput.

Curiously this morning at 6am there was some kind of sync event and DLM has intervened for what I think is the first time ever. It's knocked my sync down to 66Mb/s and put interleaving on. Unfortunately I'd stopped the monitoring the evening before (sod's law, eh?) but I had a look this morning and I'm now showing an attainable rate of 78Mb/s instead of 73Mb/s. Probably just a coincidence and it wasn't that that fixed the throughput.

As you say there are more important things to do and plenty of people would love to have 30Mb/s and I only suffer it for a few days every couple of months. Still - I'm an engineer and this bugs me 

[mervl]

Possibly not a coincidence whilst we're speculating (it's fun, isn't it?). I occasionally get disturbances, some of which are associated with latency increases (noise? not obvious but INP jumps for no apparent reason) but they usually involve resyncs and seem invariably to end with a resync to clear something. I'm not an engineer, but my my layman's perspective is that all system management software (e.g. the cab DSLAM) can be subject to occasional unexplained erratic behaviour - of course there is always a reason but its processes are so complex that the interaction isn't completely understood by any normal human brain. (Damp and cold plays havoc with electronics doesn't it?). Like humans they seem to get used to their environment and have a moan when it changes, before they (usually) grin and bear it with equanimity. I'm risking real trouble here, but I've yet to come across the software upgrade that doesn't have a sort of settling in period. Wait before you complain would have kept me out of a lot of hassle!

So a long time ago I adopted a principle: significant fail and I'll give it up to 36 hours to recover, less than optimal performance and I'll give it around 3-5 days.  Works every time, unless there's something obvious seriously faulty.

[andrue]

..aaaaand here we go again. 19th of April at 4pm the jitter strikes:



With the speed test to prove it:

Before:



After:



I've notified Support and now I wait I guess. Only odd thing - I was expecting it tomorrow based on 'every 60 days'. But it was on the dot of 4pm which I expected (1500utc).

[andrue]

Back to normal now. Nick said that when he ran diags on my line last Friday it reported a 'profile mismatch' and BT claim to have cleared that over the weekend (although Nick didn't know that until he got in today). I tried to connect using my laptop rather than through the router when I got in from work but that failed. I gave up and went back to the router and apparently it's fine.

Curious.



Hasn't really answered many questions but if there was a profile fault I can perhaps see that impacting latency and it's possible that BT's fix wouldn't take effect until I got a new session. I did notice though that Sat and Sun midnight the latency calmed down for an hour. Hasn't done that before though and might not mean anything.

No idea what was wrong with my laptop. It attempted a connect but then the hard drive jammed on and it became unusable. Had to force it to reboot.

[mervl]

Just possibly an interesting development on my lines steady deterioration (which I had put down to increasing FTTC take up) - mainly affecting average latency and uploads. The exchange link failed yesterday, and apart from the RSS feed IDNet/BTWholesale reporting operating perfectly with updates throughout, after the fibres were re-terminated on the patch at the exchange, everything is now as good as it was originally. Makes me think perhaps that in the rush that is DSL upgrades, not all the physical connections in the network are made or checked as they should be (especially at the BTWholesale bits at the exchange - and in the fibre cabs?). And not picked up by remote diagnostics up until a total fail. It's the way of the world, unfortunately. And I suspect we've all been there . . . more haste less speed, literally.

[mervl]

error post!!

[andrue]

Here's hoping it stays that way for you 

[andrue]

Well..there's a thing. The 19th of June has been and gone along with the 20th and this time no slow down. There is a difference though - I changed the router. Now what's weird about that is that I have previously demonstrated the issue connecting direct from my laptop so had ruled the router out as the cause 

It looks like my old router was doing something every 60 days that screwed up the connection and took around four days to clear - but that sounds mad. It's either that or the fault has finally been fixed. 

Hmm..although on the 19th there was of course that BT fault that wrecked our connections for most of the afternoon. Maybe that somehow 'innoculated' me.