High Sync Speed, Low Download Speed

gord · 5 Sep 2015 at 18:15

Hi all,

I've had this problem for the last few days on our usually very stable line. Despite us not changing anything we've recently had a period of instability on our line with some random disconnects. Unfortunately we're still in the world of ADSL here. I'm currently sync'd at 3.5mbps with a line attenuation of 47db and noise margin of 13db, it's been sync'd at this speed for the last 8 hours. It did lose connection over night but it was sync'd all day yesterday at 3.9mbps.

The residing problem is my actual download speed appears to be capped at 0.45mbps. Am I just a victim of the DLM forcing a lower speed on me until it realises it can actually go fast again?

I've contacted our provider, Xilo, who have been very responsive. But the hoops you have to jump through are quite frustrating. I've done the whole try different filters, move the router to the test socket, disconnect everything routine.

Any thoughts are much appreciated.

MissChief · 5 Sep 2015 at 20:54

Do you mean 450kbps (0.45MB/s)? If so that's about right. You may be confusing bits and bytes.

andy_mk3 · 5 Sep 2015 at 20:58

As MissChief says I think you're confusing bits and bytes.

I do think you can get a little more speed from your line though, SNR can usually drop to about 7 or 8db and stay stable.

gord · 5 Sep 2015 at 21:23

My download sync is currently 3488 kbps.

My actual download bandwidth is currently maxing at 470kbps. That's not right though. That's like 47KB/s. My bandwidth should be nearer 340KB/s.

My SNR has dropped to 8 now as it does in the evenings. I'm very happy with my connection sync considering where I am. The problem I have is I'm no longer getting the real speed my connection should give.

Sparx · 5 Sep 2015 at 22:21

gord said:
My download sync is currently 3488 kbps.

My actual download bandwidth is currently maxing at 470kbps. That's not right though. That's like 47KB/s. My bandwidth should be nearer 340KB/s.

My SNR has dropped to 8 now as it does in the evenings. I'm very happy with my connection sync considering where I am. The problem I have is I'm no longer getting the real speed my connection should give.

Are you sure it's 470kbps? Can you screenshot us a download?

gord · 5 Sep 2015 at 23:10

No problemo, combined some sync stats in with a test download file that won't pull down at more than 50KB/s, when I should be getting 300.

andy_mk3 · 5 Sep 2015 at 23:40

How is your PC connected? Are all devices the same? If wireless have you tried via network cable?

MissChief · 5 Sep 2015 at 23:44

Ok, to get your maximum download speed in megaBYTES you divide your broadband speed, measured in megaBITS, by eight. In your case 3488/8=a maximum of 0.436 MegaBYTES per second. If you really are getting only 50kb/s as in that pic then something is wrong.

gord · 5 Sep 2015 at 23:45

PC is wired. Phone is wireless. Tried a laptop on the wireless while the router was plugged into the test socket. All the same symptoms.

bledd · 6 Sep 2015 at 06:14

How is your ping?

Maybe some machines on your network are preloading the Windows 10 files..?

mrkev · 6 Sep 2015 at 13:53

this wouldn't be a MTU issue would it? http://www.dslreports.com/faq/5793

gord · 6 Sep 2015 at 17:13

bledd. said:
How is your ping?

Maybe some machines on your network are preloading the Windows 10 files..?

Normal, 40ish.

mrkev said:
this wouldn't be a MTU issue would it? http://www.dslreports.com/faq/5793

I've always had mine set to 1492 as per the intro to that article. It's never given me a problem before. My connection has been very good and reliable for the distance I am from our exchange for ages. I have not changed anything.

KIA · 6 Sep 2015 at 17:24

1) Run the test @ http://speedtest.btwholesale.com/
2) Click

3) Post a screenshot of the IP profile info.

gord · 6 Sep 2015 at 18:25

Unfortunately KIA I have tried that and it consistently gives me this error:

Results Image not loaded

1. Best Effort Test:

Download Speed : 0.49 Mbps

Your speed test has completed and the results are shown above, however during the test an error occurred while trying to retrieve additional details regarding your service. As a result we are unable to determine if the speed you received during the test is acceptable for your service. Please re-run the test if you require this additional information.

Re-running the test does not give me the additional information.

Is there another way to find my IP profile because I'm fairly sure mine has gone **** up?

gord · 6 Sep 2015 at 20:14

And just like that I'm back to full download speed.

I'm convinced this was the DLM kicking in now. Once again I did absolutely nothing to fix this. All that's happened is my line has been stable again for a while and my IP profile has apparently returned to normal. It's a pretty frustrating problem though because you effectively have little control over solving it.

Thanks for all of the pointers people.

Sparx · 6 Sep 2015 at 20:33

Do you hear any noise or experience interference on your phone line?

Also what type of BT socket do you have fitted? It might be worth investing in a VDSL faceplate if you don't already have one - see here.

gord · 7 Sep 2015 at 10:21

Our faceplate isn't too old. It's not a vDSL one though, could it make much difference? I did a quiet test on our phone and there was no odd noises or interference as far as I could tell. Whatever originally caused the interference/noise/instability cleared up relatively quickly it seems but by then the damage was done, my profile had been lowered and I had to wait. 5 days with 50KB/s download speed feels like an eternity.

Sparx · 9 Sep 2015 at 21:26

For the sake of £9 I'd invest in one either way. They were specifically manufactured to improve FTTC connections and reduce interference etc.

It can only help, either reduce the noise and/or increase your sync speed I've seen the last 3 I've fitted.