From BT to Plus.Net: speed observation

[#1]

Hi all,
  I thought it might be interesting to someone. I have moved from BT Infinity 1 to Plus Net Unlimited Fibre Broadband about 2 weeks ago. Measured using speedtest.net over 2 weeks prior to switch, my BT Infinity stats were:
  Ping: 18ms
  Down: 20.20Mbps
  Up: 2.62Mbps
  Once I moved to PlusNet - keeping all the same equipment (OpenReach modem and my own router), the same settings, the same cabling, the same absolutely everything - apart from username and password on my own router (Asus RT-N66U), which was changed from BT credentials to Plus.Net credentials, I'm consistently getting the following stats on Plus.Net:
  Ping: 20ms
  Down: 17.24Mbps
  Up: 2.69Mbps
  In other words, I lost about 3Mbps in downstream and about 2ms in ping. This difference is repeatable over multiple previous BT measurements and multiple current Plus.Net measurements.
  I wonder whether anyone experienced that before and whether there is a meaningful explanation beyond "more people use Plus.Net than BT" (because that's not true in our area)?
Regards,
  Maksym

[#2]

This was probably nothing to do with Plusnet but actually the DLM on the DSLAM kicking in when you switched provider, but then if you've not switched equipment this wouldn't make much sense... however it depends on what happens regarding you lines profile and also if your line stats have changed...
Would I be right to say you can access your lines stats?

[#3]

I can't see how this will be anything to do with DLM?

[#4]

it looks a bit like interleaving to me, so I guess it could be DLM related...

[#5]

If DLM added interleaving I would expect an increase of ping by at least 8ms.
When I moved from BT to PlusNet the modem didn't resync at all, so my sync speeds remained unchanged.  Download went down because I moved from BT 80/20 to PlusNet 40/20. 
Upload on BT wholesale improved from around 14Mbps to around 17Mbps; but that tester always underestimates upload
.
I did have interleaving at the time of the changover; I had been on fastpath earlier and fastpath returned soon after the change: however I am sure that was not ISP related.
Ping went down considerably on the move to PlusNet because BT Retail had crazy internal routing (Winchester->Sheffield->London) that added around 9ms to ping.
That is just one case: I suspect there are other situations where a user would see greater latency from PlusNet.
~~~
It is just possible OP happened to suffer interleaving just as he moved to Plusnet, and that added latency which was partly offset by better PlusNet

[#6]

Quote from: sjptd

If DLM added interleaving I would expect an increase of ping by at least 8ms.

Well it kinda depends really, doesn't it?
Theoretically you'd get an extra 8ms latency, but we're not really comparing like for like (not even sure which servers were used for those two speed tests, nor the time of day of either).
But losing about 3 Mbps on 20 Mbps tallies with when I lose 7Mbps on 50 (due to interleaving).
Now the OPs connection has been on for a couple of weeks it should've settled down, but it's hard to know (just by looking at speedtests) whether they're on fastpath or interleaved or whether G.INP is on/off etc.

[#7]

Just thought...
Maybe the EU is seeing an increase in ping due to routing change to Plusnet... AFAIK to get to Plusnet's network/gateways the connection goes through BT Wholesale so considering BT's gateways will probably be on the BT Wholesale network where Plusnet's are outside I could expect a few extra milliseconds delay!
Either way I wouldn't expect 2 connections to be exactly the same between providers, even if they where provided using the same line and didn't lose sync.
When I say DLM involvement, it might not have put him on an interleaved profile but maybe G.INP... or anything newer than what he was on before...
AFAIK DLM is always reactivated upon moving provider and if the EU's connection was fine before on an older DLM setting and newer settings have been released in the meantime then the EU's connection might be assigned a newer setting than the last..
The fact is a lot is happening on the FTTC networks so setting changes are to be expected.

[#8]

> Would I be right to say you can access your lines stats?
I've not done this on fibre, but did access them on ADSL. I'm technical enough to access line stats if I have a pointer at howto...

[#9]

> If DLM added interleaving I would expect an increase of ping by at least 8ms.
Can I force DLM not to switch interleaving on? I could do so on ADSL line by tweaking my modem router, but this is OpenReach modem and I never accessed it...

[#10]

HI Maksym, unlike ADSL there is no manual interaction with DLM on fibre it's done automatically so there is no way to remove interleaving other than DLM removing it itself if it deems it necessary to do so.

[#11]

Try disconnecting/reconnecting to Plusnet and then try some tests. You will find there can be 4ms difference depending on your gateway routing.

[#12]

Cool, will look around for modems that can replace this openreach and have stats available. Always up for tinkering.

[#13]

tinkering could have major implications for yourself so I do advise your careful.
Also forgive me if you did, but I haven't seen you mention what modem you have...
If it is a HG612 then this can be unlocked fairly easy depending on your PC knowledge!

[#14]

Having done some limited embedded development before (bits for myself for Lacie Fuel and Asus WRT), I'm fairly comfortable with tinkering, but thanks for heads up.
The modem is ECI /R revision - so no, not easily unlocked, although I was contemplating getting a second-hand off ebay and unlocking it, but if I'm going to buy something, I could as well go for Fritz!Box 7490. Or really ECI.
I've been reading on G.INP and it seems HG612 cannot do that, so not future-proof either.

[#15]

Quote from: maksym

I've been reading on G.INP and it seems HG612 cannot do that, so not future-proof either.

The HG612 does G.INP just fine, the issues are more with ECI modems.