cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 
Highlighted
Aspiring Contributor
742 Views
Message 1 of 11

Not clever enough to solve my own problem (high sync / lower throughput than expected)

Go to solution

 

Hello everyone. Below is how far I have gotten on my own, but now I need some help from clever people to reach the answer.

The issue

With the sync rate I am getting (80/20 without fail), it strikes me that I should be getting better throughput (speed test jumps to 67/17 immediately and stays there throughout)? Ping is typically 8-9 ms but often 5-6 ms depending on what you’re doing, time of day etc. The only outages we’ve ever had have been during heavy rain. Otherwise, pretty much faultless service for years.

My stuff

BT package: Superfast Fibre 2 Unlimited
Wholesale product: Maybe WBC FTTC 80/20?
Maximum throughput: 76 Mbps downstream / 19 Mbps upstream
Average throughput: 67Mbps downstream / 18Mbps upstream
Technology: Hybrid fibre / Fibre to the Cabinet (FTTC)
Transmission technology: Very High Speed Digital Subscriber Line 2 (VDSL2)
Exchange: GUILDFORD
Cabinet: 122 - Huwai - approx. 313 m away from property.
Dropwire looks like it’s not copper.
Filtered faceplate (these are fab by the way)
Huawei Echolife HG612 3B modem (but I briefly connected the BT Smart Hub to get the screenshot below)
40 cm CW1308 modem lead
Unifi Security Gateway router
...onwards into the home

Possible answer?

I couldn’t help but note that my IP Profile is almost exactly what this states: “21CN System - For ADSL2+ / WBC Products (Up to 24Mbps ADSL) With effect from late 2011, BT introduced a new Quantisation DLM system that results in much quicker updating of the IP profile. The calculation is based on your last sync speed minus an allowance for TCP & ATM overheads. The calculation should always be a fixed rate at 88.2% of your sync speed.

Other

If you could explain what the line stats mean, that would be good.

Thanks in advance for any guidance, more than happy to investigate further.

Screenshots

2019-03-31 - BT DSL Checker results.png

 

2019-03-31 - BT Smart Hub stats - new cable and faceplate.png

 

0 Ratings
Reply
10 REPLIES 10
Highlighted
Distinguished Sage
Distinguished Sage
739 Views
Message 2 of 11

Re: Not clever enough to solve my own problem (high sync / lower throughput than expected)

Go to solution

Run btspeedtester and when first test completes run diagnostic test and post result must be done with wired connection  http://www.speedtest.btwholesale.com/



If you like a post, or want to say thanks for a helpful answer, please click on the Ratings 'Thumbs up' on left hand side.
If someone answers your question correctly please let other members know by clicking on ’Mark as Accepted Solution’.
Highlighted
Aspiring Contributor
711 Views
Message 3 of 11

Re: Not clever enough to solve my own problem (high sync / lower throughput than expected)

Go to solution

Hi. Ok this is what I got. I recall doing this a couple of weeks ago and it was higher, but either way while I'd say this is a bit low it's not dreadfully different than day-to-day performance.

2019-04-01 - BT Wholesale Speed Test results.png

 

0 Ratings
Reply
Highlighted
Distinguished Sage
Distinguished Sage
703 Views
Message 4 of 11

Re: Not clever enough to solve my own problem (high sync / lower throughput than expected)

Go to solution

It looks like your profile is set to retransmission high at about 91% of connection speed and your download speed is ok for your profile. BT won't help at present as profile is ok and set bt DLM



If you like a post, or want to say thanks for a helpful answer, please click on the Ratings 'Thumbs up' on left hand side.
If someone answers your question correctly please let other members know by clicking on ’Mark as Accepted Solution’.
Highlighted
Aspiring Contributor
653 Views
Message 5 of 11

Re: Not clever enough to solve my own problem (high sync / lower throughput than expected)

Go to solution

Ok, just so I understand this correctly (I don't): 1) Retransmission High is basically a setting where the system is saying 'this connection isn't good enough for X, so I'm going to try Y and see how it goes on that' - is that right? 2) Where you say it's set by DLM, how frequently is that DLM updated? Or can it ever be? Reason I ask is because when we moved in, *everything* was DIY-ed by a really bad DIY-er (I touched the living room light and got a shock, because the entire fitting was live). This included a total mess of telephone wires everywhere which, with a lot of Googling, I sorted - now the broadband is just plugged into the master socket and just sorting that wiring actually made a good difference on speed.

0 Ratings
Reply
Highlighted
Sage
637 Views
Message 6 of 11

Re: Not clever enough to solve my own problem (high sync / lower throughput than expected)

Go to solution

DLM montors your line continuously. If, as you say, you have now resolved all the problems with the line then DLM will relent and reduce interleaving.

 

Highlighted
624 Views
Message 7 of 11

Re: Not clever enough to solve my own problem (high sync / lower throughput than expected)

Go to solution

@pippincpwrote:

DLM montors your line continuously. If, as you say, you have now resolved all the problems with the line then DLM will relent and reduce interleaving.

 


Hub stats show Fast Path so OP's line isn't on interleaving.

0 Ratings
Reply
Highlighted
Distinguished Sage
Distinguished Sage
621 Views
Message 8 of 11

Re: Not clever enough to solve my own problem (high sync / lower throughput than expected)

Go to solution

@brookheather wrote:

@pippincpwrote:

DLM montors your line continuously. If, as you say, you have now resolved all the problems with the line then DLM will relent and reduce interleaving.

 


Hub stats show Fast Path so OP's line isn't on interleaving.


hub stats show fast all the time regardless of whether interleaving or fast - about time BT got this right



If you like a post, or want to say thanks for a helpful answer, please click on the Ratings 'Thumbs up' on left hand side.
If someone answers your question correctly please let other members know by clicking on ’Mark as Accepted Solution’.
Highlighted
Aspiring Contributor
567 Views
Message 9 of 11

Re: Not clever enough to solve my own problem (high sync / lower throughput than expected)

Go to solution

Ok, well thanks for all the help. It's now slightly faster again (although I'm testing more consistently on ethernet) which is good. I get the feeling it's not going to get onto a higher IP Profile but will wait and see.

0 Ratings
Reply
Highlighted
Aspiring Contributor
255 Views
Message 10 of 11

Re: Not clever enough to solve my own problem (high sync / lower throughput than expected)

Go to solution

TL;DR. Improving wiring provides a measurable benefit not only with increased speed, but also stability. 

Just as an update to everyone that helped, I’m pleased to say in the weeks that followed the performance improved. I now consistently get 71/18 (testing on WiFi) and any speed test immediately jumps to that figure and stays there for the rest of the test (previously it would start a bit lower and creep up). I have to confess I don’t quite understand whether this is the correct maximum for my line or not but I’m definitely pleased with the results.

I am today having Halo 100 fitted (they told me they were installing FTTP but I think they are wrong) so will see how that goes.

Thanks again to those who helped.

0 Ratings
Reply