Help needed to understand upload problem

[MT10]

Hello, my line is 900yds copper from house to cabinet and 600yds fibre from there to exchange. My download speed is 13MBpS, upload shows at approx 0.45 which I know is very poor. The line has been examined several times and has no faults. My problem is this: I have been trying to upload a 450MB file. The first 25% uploads fairly consistently but the transfer speed gets progressively slower and slower to a stuttering crawl. It takes several hours to get to 90%, it then hangs for several minutes and drops back to low 80s% and does this repeatedly, getting to 92-96% then dropping down to 78-84%. Having got to 96% again I watched as it hung and then dropped to 0% at which point I cancelled it. Can anyone tell me why this is happening? No one else is using the internet as it's overnight, in any case downloads are crushingly slow when uploading. I can't understand how data can be 'un-transferred' ie how what's been transferred can go backwards as if it's never happened. Do I need an engineer visit for something to be adjusted? Many thanks.

[Keith_Beddoe]

@MT10 

What upload connection speed are you supposed to get?

Enter your number into this form, and display the results here, after editing out your phone number.

https://www.broadbandchecker.btwholesale.com/#/ADSL

Are you connecting directly to the home hub using an Ethernet cable?

[MT10]

Thanks Keith, stats below. Downloads are meant to be 11-20 and uploads 1-2 (so the actual speed falls considerably short). Yes ethernet connected and the line comes direct into the master socket 5C. I could manage with the slow upload speed if it stayed constant but not when it keeps dropping to virtually zero. As an aside I thought downloads and uploads were entirely separate and had no effect on each other, yet my downloads are severly impacted if trying to upload something eg Google homepage takes 20 seconds to load?

Exchange REDHILL is served by Cabinet 25

Featured Products Downstream Line Rate(Mbps) Upstream Line Rate (Mbps) Downstream HandbackThreshold(Mbps) WBC FTTC Availability Date WBC SOGEA Availability Date Left in JumperHigh Low High Low        VDSL Range A (Clean)

VDSL Range B (Impacted)

18.7	13.4	2	0.8	11.4	Available	Available	--
18	11.4	1.9	0.6	7.9	Available	Available	--

Featured Products Downstream Line Rate(Mbps) Upstream Line Rate (Mbps) Downstream Range (Mbps) Availability Date FTTP Install ProcessFTTP on Demand

330

30

--

Available

--

ADSL Products Downstream Line Rate (Mbps) Upstream Line Rate (Mbps) Downstream Range(Mbps) ADSL Availability Date WBC SOADSL Availability Date Left in JumperWBC ADSL 2+WBC ADSL2+ Annex MADSL MaxWBC Fixed RateFixed Rate

Up to 3.5	--	1.5 to 5.5	Available	Available	Yes
Up to 3.5	Up to 0.5	1.5 to 5.5	Available	Available	Yes
Up to 2	--	1.5 to 4.5	Available	Available	--
1	--	--	Available	Available	Yes
1	--	--	Available	--	--

Observed Speeds VDSL ADSLMax Observed Downstream SpeedMax Observed Upstream SpeedObserved Date

14.27	11.51
0.58	0.44
2019-12-18	2019-09-29

Other Offerings Availability DateVDSL MulticastADSL Multicast

Available

Available

Premise Environment StatusBridge TapVRINTE FacePlateLast Test Date

N

N

N

17-11-2020

Exchange Product Restrictions StatusFTTP Priority ExchangeWLR WithdrawalSOADSL Restriction

N

N

Y

The premise/line is associated with exchange which is NOT part of current fibre priority programme.

The premise/line is associated with exchange where WLR is not withdrawn.

The premise/line is associated with exchange where SOADSL service is restricted.

FTTP is not available.

[Keith_Beddoe]

Download speed will be impacted if you use up all of the upload speed, as downloaded packets have to be acknowledged, before more are sent, and this is done via the upload path. So if the upload path is fully utilised, it will affect your downloads.

It really the connection speed you need to look at, as that is the figure referred to on the availability chart.

If you can display the connection speeds from the home hub, then it may become a bit clearer.

[MT10]

Thanks Keith, are these the stats you mean?

Downstream sync speed:

15.935 Mbps

Upstream sync speed:

796 Kbps

[Keith_Beddoe]

---

@MT10 wrote:

Thanks Keith, are these the stats you mean?

Downstream sync speed:

15.935 Mbps

Upstream sync speed:

796 Kbps

---

Downstream is within expected range but upstream is slightly below, but that is not guaranteed, and it depends very much on the quality (frequency bandwidth) of your line. I assume you are not using any form of powerline type connectors, as they can affect the line performance, especially when data is being transferred?

You may be able to get a better connection speed by altering the way you have things connected up.

What does your master phone socket look like?

Which BT Home hub are you using?

[MT10]

It's No 7; the router is the Smart Hub, about a year old,  and the ethernet goes direct from it to the desktop.  Thank you for clarifying why downloads are affected by uploads, I understand that now, but what I don't understand is why a file upload should get progressively slower to the point where it stops completely and then goes back on itself?

[Keith_Beddoe]

Please could you try connecting thing up as shown below, and see if the connection speed improved.

Note:-Those type of NTEs do have issues with poor connection between the front and back sections, so this may help to prove whether that is the problem.

Do you have any other phone sockets or extension wiring?

As for downloads going backwards, there is an explanation for that.

Downloads consist of blocks of data of a specific length. At the end of each block, the download is checked for errors. If there are errors, then that block is rejected, an the download counter has to go back to the start of the block, and attempt to download it again.

If there are errors on your line, or if there is a loss of communications, then that will be seen by the server, as a reason to restart the download at the end of the last good data block.

[MT10]

No, it's actually slightly worse. There are no other phone sockets or internal wiring.

Your 3rd para is about downloads, did you mean uploads? If so, judging by where the upload goes back to, my upload is tripping within a block size of 30-35MB - this seems quite large, would that be normal? If it's caused by line errors should these be looked into by an engineer? Thanks

[Keith_Beddoe]

Put the connection back as it was.

Yes I did mean uploads, the same applies both ways.

I suspect what is happening is that you are uploading data to the home hub faster than it can transmit it to the other end. The home hub input buffer is overflowing and the session is being dropped and being reset.

Whatever program you are using to send the data to the home hub, adjust it so that it cannot send data faster than the actual upload speed that you have available. That way, the input buffer of the home hub should not overflow.

If its an FTP program, then you should be able to adjust the upload speed so that it matches the actual rate that you have available. Start at about 500Kbs and then see if the upload progresses. Then increase it a bit at a time until you get to about 700Kbs.