cancel
Showing results for 
Search instead for 
Did you mean: 

Significant drop in connection speed

MJN
Aspiring Pro
Posts: 1,103
Thanks: 54
Fixes: 2
Registered: 26-08-2010

Significant drop in connection speed

Hi Plusnet,
I'll be short (and sweet!) with this one - late on Sat 26th Oct my sync speed dropped from ~5500kbps to 2169kbps and has stayed there ever since. At the same time the SNR rose from ~11dB to ~25dB.
You have probably got more detailed logs than me, however my own stats are captured in the dynamic graphs here.
Is there anything that might explain this and, more importantly, anything that can be done about it?
On a more general note, looking back at the last year of stats there is an emerging trend of decreasing connection speeds. Confusingly (to me at least), the downstream attenuation is currently at the lowest ever level yet so is my sync rate!
Many thanks,
Mathew
16 REPLIES
TheTruth
Newbie
Posts: 1
Registered: 29-10-2013

Re: Significant drop in connection speed

Tell me about it!!!!!
I used to get a decent download speed, now the BTW Performance Test states:
Download speedachieved during the test was - 0.19 Mbps
I'm moving to another provider. This is beyond a joke!!!!!
MJN
Aspiring Pro
Posts: 1,103
Thanks: 54
Fixes: 2
Registered: 26-08-2010

Re: Significant drop in connection speed

The causes behind our problems will almost certainly be very different so I'd recommend (and appreciate) you starting a new thread to cover your issues if that's okay.
Mathew
Plusnet Staff
Plusnet Staff
Posts: 6,346
Thanks: 31
Fixes: 5
Registered: 26-11-2011

Re: Significant drop in connection speed

Hi Mathew,
I've just taken a look at your line which shows, exactly as your graphing is reporting that your sync speeds are dropping at quite a rate. The problem is, is that there appears to be some kind of interference on the line as your SNR (which is targetted at 12db) has shot up to 25db - it's a case of finding out what could be causing this. The higher your SNR, the lower your sync rate will be so the loss in speed does make sense from that point of view.
I can reset the lien for you and move the SNR back down, however, it is unlikely to fix the problem entirely. Here's your connection graph:
<img src="http://community.plus.net/visualradius/generated/image13831256337433.png"/>
As you can see, there aren't too many drops, which is what leads me to think interference is causing your SNR to shoot up. Let me know if you'd like for me to reset the line. In the meantime, it might be worthwhile just checking for any equipment that might be causing this issue for you.
Chris Pettitt
Cloud Environments Engineer
Community Veteran
Posts: 26,692
Thanks: 916
Fixes: 10
Registered: 10-04-2007

Re: Significant drop in connection speed

Looking at your graphs thee seems to have been a brief event which generated a lot of errors. It will have resynced during the event at a much lower speed. When the event ended the sync stays the same but with the removal of the interference the SNR will shoot right up.
Have you tried a resync? That should be at 12 db with a much higher sync. If it doesn't it could mean the line has been banded.
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)
MJN
Aspiring Pro
Posts: 1,103
Thanks: 54
Fixes: 2
Registered: 26-08-2010

Re: Significant drop in connection speed

Hi Chris,
Many thanks for your prompt response and initial investigation. If you could reset the line that'd be appreciated as I am at a loss at to what other factor might be causing an issue and so do not know what else to do.
I can confirm there is no new equipment around and the house wiring is newish (2007) and in good condition for what it's worth. I have always viewed the TG585 router with some suspicion given its poor performance in many other respects however as I purchased this from Plusnet I consider it to be part of the service and so am not inclined to fork out for a new router from a 3rd party on the off-chance that it might be the culprit as it might well not be to blame.
Thanks again,
Mathew
Community Veteran
Posts: 26,692
Thanks: 916
Fixes: 10
Registered: 10-04-2007

Re: Significant drop in connection speed

I've not seen many (if any) reports that question the TG582 has issues with syncing when on the latest firmware. My own experience when I first got one was that there were a couple of concerns but updating the firmware to the current release resolved that. I'm wondering if the older 585 had issues?
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)
MJN
Aspiring Pro
Posts: 1,103
Thanks: 54
Fixes: 2
Registered: 26-08-2010

Re: Significant drop in connection speed

Quote from: jelv
Looking at your graphs thee seems to have been a brief event which generated a lot of errors. It will have resynced during the event at a much lower speed. When the event ended the sync stays the same but with the removal of the interference the SNR will shoot right up.

Thanks for your thoughts Jelv, they do make sense.
Quote
Have you tried a resync? That should be at 12 db with a much higher sync. If it doesn't it could mean the line has been banded.

'Resync' as in that which would occur by rebooting? If so, no, I haven't tried that as I didn't want to upset what appears to be an already flaky connection.
The gradual degradation in service is already pushing my tolerance levels (I've not renewed the advance line rental as I'm on the cusp of looking elsewhere) and I didn't want to make it any more difficult for Plusnet to diagnose what appears to be a very intermittent issue - I'd rather they see the problem 'live' than rely on me retrospectively reporting it.
Plusnet Staff
Plusnet Staff
Posts: 6,346
Thanks: 31
Fixes: 5
Registered: 26-11-2011

Re: Significant drop in connection speed

The SNR has now dropped back to 9db which is good to see with a SNR Target of 9db.
I think it'd be a good idea to keep an eye on those graphs over the next couple of days to see if the SNR changes dramatically during this time. Hopefully we can build a picture of when the interference is hitting your connection. It's quite difficult for us to see as the SNR can vary at any time and the graph isn't registering any drops out of the ordinary.
Can you let us know if you notice a further dip in speeds so I can take another look for you?
I've updated your speed profile so you may notice a loss of connection for a brief time whilst this updates.
Chris Pettitt
Cloud Environments Engineer
Community Veteran
Posts: 26,692
Thanks: 916
Fixes: 10
Registered: 10-04-2007

Re: Significant drop in connection speed

Quote from: MJN
'Resync' as in that which would occur by rebooting? If so, no, I haven't tried that as I didn't want to upset what appears to be an already flaky connection.

If you can see from your graphs that you've had a single short period during which it resynced at a lot lower speed and that following that there have been no significant errors logged it is safe to do ONE resync/reboot. It's when people start doing loads of them that it clouds the issue.
Have you any idea what happened at the time the problem happened? Could it have been an incoming call? It's worth ringing your own number and leaving it ringing to see if that causes similar errors.
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)
MJN
Aspiring Pro
Posts: 1,103
Thanks: 54
Fixes: 2
Registered: 26-08-2010

Re: Significant drop in connection speed

Thanks Chris. I'm away from home at the moment however the new graphs are looking good - will see how we get on. As much as I wish I didn't have these problems, it is greatly appreciated how keen and willing you are to try and help sorting them out so thank you for that.
Jelv, the graphs suggest it was around 11pm on Saturday and there was very little going on at that time. In fact, the kids were in bed and we were just chatting in the lounge and there was no TV or heating on etc so I'd expect a reasonably 'quiet' time from a house-bourne interference perspective.
MJN
Aspiring Pro
Posts: 1,103
Thanks: 54
Fixes: 2
Registered: 26-08-2010

Re: Significant drop in connection speed

Incidentally, can either of you shed any light on why the attenuation on the graphs dropped at the point at which I ended up on the degraded sync rate and yet is now back up to where it always sits immeditalely following the reset?
Isn't the attentuation a function of the line e.g. length, condition, etc and not something that should be influenced by anything you do?
Plusnet Staff
Plusnet Staff
Posts: 6,346
Thanks: 31
Fixes: 5
Registered: 26-11-2011

Re: Significant drop in connection speed

Line Attenuation changing is never really a good sign. I have seen slight fluctuations before, but I think that's based on the reporting that we get from our suppliers which can change is by around 0.5db. That's another thing we could do with keeping an eye on really as the line attenuation should really budge.
Chris Pettitt
Cloud Environments Engineer
MJN
Aspiring Pro
Posts: 1,103
Thanks: 54
Fixes: 2
Registered: 26-08-2010

Re: Significant drop in connection speed

It did strike me as odd. Moreso that the changes correlate exactly with the issue on Saturday night and your reset this morning. Noone is at home and so in-house electrical activity is virtually nil.
It seems counter-intuitive to me though that the lower sync rate occured with the lower attenuation!
Community Veteran
Posts: 26,692
Thanks: 916
Fixes: 10
Registered: 10-04-2007

Re: Significant drop in connection speed

If it switched from say ADSL2+ to ADSL1 the attenuation might be measured over a different set of frequencies. Did you notice if the mode had changed?
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)