Odd Speed Test Issue

I've noticed recently a bit of an odd issue with the TBB speed test on my FTTC connection. The most recent results are here. Basically the TBB protocol results vary wildly from the HTTPx6 results. This is in comparison to a past test here where although slower, the gulf was not as wide and it was more consistent. I am using a set of homeplug adapters (Solwise NET-PL-500AV-PIGGY) so do you think they might be failing or being subjected to interference from somewhere which is causing this?

P.S. I should point out I've not noticed any major issues actually using the connection but concerned that the results may be a sign of future problems so I would like to get to the bottom of this issue anyway.

Edited by ciday (Mon 11-Jan-16 14:44:22)

It may be evidence of traffic management, as tbbx1 download is over a port often traffic shapped (deliberate choice by us). Or it could just be congestion and there are hints of this with the shape of the httpx6 which is six file downloads at once. It is possible the HomePlugs are part of the bottle neck, so worth moving PC to try direct into router at some point.

You can test the congestion theory with these tests

http://labs.thinkbroadband.com/speedtest/?site=omega...
(Will download a single file over HTTP)

http://labs.thinkbroadband.com/speedtest/
(Will download the same file, but six at once)

On a good connection the two should be pretty much the same, so once the tests have run post the share links you get from one of the buttons at the end.

Nope. Still pretty dire. I'll test it later directly from the modem when I can. But with the current set up the results are as follows.

Single Thread
x6

EDIT:
I've tested the connection by plugging a laptop via ethernet cable directly into the VDSL modem (A Huawei HG612 3B unlocked) with everything else removed. Turns out the homeplug adapters may be to blame. Either that or the mains wiring in my home.
Single Thread Test Direct
x6 Test Direct

I reconnected the home plug and using the wifi on the same laptop got these results:
Single Thread via Homeplug
x6 via Homeplug

My question now is why does the single thread test get impacted so badly by the homeplugs? I did check to make sure the QoS on the router and the homplugs are off. Could it be a technical fault with the homeplugs themselves?

Edited by ciday (Mon 11-Jan-16 18:04:34)

Should not normally be, but there may be some errors and by doing more downloads at once we manage to get more speed across the link in that time.

Most Home Plugs come with diagnostic software that lets you look at connection speeds and thus determine if they may be the issue.

At least it looks like any issues with the ISP are ruled out.

I've had a look at the diag software. It seems to think the link between the home plugs is fine with a speed of about 170Mbps. My friend who actually runs the ISP I use (A small business reseller) seems to think a sag in incoming voltage might cause issues with some homeplugs. However I do not have a multimeter to test that.

In reply to a post by ciday:

Nope. Still pretty dire. I'll test it later directly from the modem when I can. But with the current set up the results are as follows.
...
I reconnected the home plug and using the wifi on the same laptop
...
My question now is why does the single thread test get impacted so badly by the homeplugs? I did check to make sure the QoS on the router and the homplugs are off. Could it be a technical fault with the homeplugs themselves?

Speed testing using wifi is always suspect. Try that laptop with an Ethernet connection into the same Homeplug as you think you were connecting to with wifi.

Edited by RobertoS (Mon 11-Jan-16 19:21:03)

Looks like there may be a WiFi issue. But I can't discount the homeplugs entirely as there is some issues with the speed. Still confused as even on WiFi my speeds were consistent and rock solid until recently.

Ethernet
WiFi

It could be the wifi in the Homeplug.

ciday/Mr Saffron - sorry to hijack but I tried the tests you linked to for the single file and the six at once. The single file gives me about 9mbps down and the same up. The six files test gives me 37.5mbps down and 9.2mbps up. I am on Sky fibre 40/10. The six files test gives me the results I would expect. The single file test is fine on the upload but way down on the download. Why is this? Thanks.

The homeplugs as far as I'm aware do not have WiFi capability.

http://www.solwise.co.uk/net-powerline-500av-piggy.htm

I think you meant to reply to me.

I read "I reconnected the home plug and using the wifi on the same laptop got these results" to mean you were connecting wirelessly to the Homeplug in whichever room you were. This kind of thing.

Still worth trying Ethernet from laptop into a remote Homeplug. Make sure the wifi on the laptop is turned off, as some kit connects by wifi even if it has an Ethernet connection available.

Because of things like

a) RWIN size
b) ISP Congestion
c) Behaviour of your Wi-Fi network

etc etc

We know you can pull the single file at 940 Mbps if you have a connection up to it, and more if you are a rare 10 Gbps user.

Wi-Fi is a shared medium, i.e. airwaves are shared so someone elses Wi-Fi may be interfering and by throwing more packets at it you swamp them.

In reply to a post by ciday:

I've had a look at the diag software. It seems to think the link between the home plugs is fine with a speed of about 170Mbps. My friend who actually runs the ISP I use (A small business reseller) seems to think a sag in incoming voltage might cause issues with some homeplugs. However I do not have a multimeter to test that.

Unlikely as the mains voltage has nothing to do with the signal transmitted. A high frequency data signal is injected onto the power lines and recovered at the destination point. There will be some extremely good filters in place to keep any 50Hz and low harmonics away from te data lines. If you could power the homeplugs from an alternative source (not advisable to try) they would still work and send data over the mains wiring even when the mains power is off.

Apologies if this comes off as snarkier than I meant (It isn't meant to be) but I already did what you suggested in my previous post. PC with WiFi off and into the router via ethernet as well as with only one laptop directly plugged into the VDSL modem to eliminate any other cause. It does appear the WiFi may be partially to blame as my previous results shown. The last test with WiFi on was to confirm if my theory was the case. It does appear there may be an issue with the WiFi itself.

For avoidance of doubt, there isn't any WiFi ability on the homeplugs I'm using and they are only there to connect the wireless router to the VDSL modem. This is because the master phone socket is downstairs in one corner of the living room and the modem has to go there, but I could not leave the router there too as wifi signal performance degrades upstairs where most of the devices and PCs in the house are. If I had the choice as well as time and inclination I would've put in ducting with ethernet cables everywhere. However this is a no go area and also a lot of the devices now in the house are phones and tablets that obviously lack ethernet ports of any sort.

This still doesn't entirely explain the odd issues but I'm willing to live with them as long as it doesn't affect the long term reliability of the connection. As I said before I was just curious to know what could be causing the odd results and if it could be a problem in future.

That also is interesting. In particular, that the router is fed by Homeplugs. What rated speed are they please? 500Mbps, from your earlier link.

Those should be OK.

Edited by RobertoS (Tue 12-Jan-16 15:49:26)

Unless there is interference in which case they may be running much less than the "headline" speed.

VDSL2 and homeplugs can interfere with each other, so it may be down to that.

Plenty of people have them co-existing fine, but replacing the home plug link between modem and router with a temporary cable for testing should show if a cable will provide much better speeds, and then its a case of figuring out a way of getting a suitable Ethernet cable installed (e.g. I use an external grade CAT5e to get from loft room to lounge down the outside of the house).

Given the house is not my own (Still live with parents) I suspect trying to put in some ethernet cable permanently is not going to be an option. I'll investigate further when I have time but thanks for the input so far guys and gals.

In reply to a post by ciday:

Given the house is not my own (Still live with parents) I suspect trying to put in some ethernet cable permanently is not going to be an option. I'll investigate further when I have time but thanks for the input so far guys and gals.

You can get flat internal CAT5E which will go under carpet or wood flooring from CPC

Shape of the cable isn't an issue. It's more my parents are fussy and don't like too many cables trailing all over the place. To put them internal in the wall would be require a disproportionate amount ofwork IMHO. Thanks anyway.

Thanks MrSaffron. My pc is connected via Ethernet as opposed to Wi-fi so obviously the other factors you mention would cause my issue I guess.