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No Throttling - really?

simmotech
Dabbler
Posts: 11
Thanks: 3
Registered: ‎22-01-2014

No Throttling - really?

I've been watching a backup to LiveDrive run all day. It has been consistently at 256KB/s.
My upload speed as shown on SpeedTest.NET is 19.2 Mbps so I am only seeing 1/8 of what is possible.
According to these forums, PlusNet does no speed throttling and also says there is no management on uploads;
LiveDrive also claim no throttling and I uploaded a 178MB file directly to my LiveDrive share (whilst the slow backup copy was still running) and got 811KB/s.
I have a Wireshark trace (which in fact was the 178MB file and can be seen publicly at simmotech.livedrive.com) which shows that the TCP Window Size gets very small and there are regular ACKs to packets that Wireshark doesn't think were sent from my machine. This is I am led to believe a way of throttling a connection but I may be mistaken.
There is also something strange with the route since a tracert show going from London to Paris and back to London again!
Tracing route to 82.129.64.210 over a maximum of 30 hops
 1     6 ms     5 ms     5 ms  lo0-central10.pcl-ag07.plus.net [195.166.128.188]
 2     5 ms     5 ms     5 ms  link-b-central10.pcl-gw02.plus.net [212.159.2.186]
 3    12 ms    12 ms    12 ms  xe-9-0-0.pcl-cr02.plus.net [212.159.0.218]
 4     8 ms     5 ms     5 ms  ae2.pcl-cr01.plus.net [195.166.129.6]
 5     9 ms     6 ms     5 ms  xe-11-1-0.edge3.London2.Level3.net [212.187.201.209]
 6    13 ms    12 ms    12 ms  ae-3-3.ebr1.Paris1.Level3.net [4.69.141.86]
 7    12 ms    13 ms    12 ms  ae-91-91.csw4.Paris1.Level3.net [4.69.161.90]
 8    12 ms    12 ms    13 ms  ae-4-90.edge5.Paris1.Level3.net [4.69.168.200]
 9    14 ms    14 ms    14 ms  be3046.ccr21.par04.atlas.cogentco.com [130.117.14.93]
10    14 ms    15 ms    14 ms  be2308.ccr21.par01.atlas.cogentco.com [154.54.73.229]
11    14 ms    14 ms    14 ms  be2274.mpd22.lon13.atlas.cogentco.com [130.117.50.97]
12    16 ms    13 ms    14 ms  be2316.ccr21.lon01.atlas.cogentco.com [154.54.73.114]
13    18 ms    20 ms    22 ms  te2-2.ccr01.lon18.atlas.cogentco.com [154.54.61.218]
14    15 ms    14 ms    14 ms  SMTPOUTB01.livedrive.com [149.6.3.90]
15    14 ms    14 ms    14 ms  82.129.64.210
I also note that Level3 is mentioned and I just noticed that traffic from that particular system may be limited according to PlusNet.
I am also assuming my connection is 'correct'. The engineer didn't bother to turn up to my house yesterday to install/check anything  Angry - I just tried connecting up my D-Link 868L router and it worked first time.
The profile is showing 78 (I think - the Plus net site is now closed for maintenance  Huh) which is higher that the estimate of 59Mbps download.
I have logged a ticket but I thought I'd ask here in case there was something else I could be checking in the meantime
8 REPLIES
ColinBe
Newbie
Posts: 8
Registered: ‎22-01-2014

Re: No Throttling - really?

You should read this article:
http://www.plus.net/support/broadband/speed_guide/traffic_management.shtml
All traffic on their network is subjected to QoS and shaped in some way, which is highly dependant on demand.
Highlighted
Community Veteran
Posts: 38,460
Thanks: 1,031
Fixes: 62
Registered: ‎15-06-2007

Re: No Throttling - really?

There is no upstream speed throttling so I can't explain the difference but then again I don't know anything about TCP Window size
Community Veteran
Posts: 5,187
Thanks: 486
Fixes: 21
Registered: ‎10-06-2010

Re: No Throttling - really?

If your MTU is 1300, that seems unnecessarily small, which probably won't be helping.
As for the TCP window size, I don't think wireshark can display the actual size if it didn't capture when the connection was initially established (with the window scaling factor).
simmotech
Dabbler
Posts: 11
Thanks: 3
Registered: ‎22-01-2014

Re: No Throttling - really?

Quote from: ColinBe
You should read this article:
http://www.plus.net/support/broadband/speed_guide/traffic_management.shtml
All traffic on their network is subjected to QoS and shaped in some way, which is highly dependant on demand.

"highly dependant on demand" - exactly. So if I was subject to QoS then I should see a highly fluctuating throughput but I don't - it is exactly 256KB/s which indicates something is causing that specific rate- though not necessarily PlusNet.
I am still a bit curious about why the traffic is seemingly going London->Paris->London via the Level3.net domain and the fact that Level3, is a Content Distribution Network, and PlusNet says that downloads via such may be "slowed during busy times". Could it be here that it is being slowed down?
Community Veteran
Posts: 3,188
Thanks: 20
Fixes: 2
Registered: ‎31-07-2007

Re: No Throttling - really?

A quick google shows its a common problem with them
Unvalued customer since 2001 funding cheap internet for others / DSL/Fibre house move 24 month regrade from 8th May 2017
simmotech
Dabbler
Posts: 11
Thanks: 3
Registered: ‎22-01-2014

Re: No Throttling - really?

Quote from: Gus
A quick google shows its a common problem with them

Who? PlusNet, LiveDrive or Level3
simmotech
Dabbler
Posts: 11
Thanks: 3
Registered: ‎22-01-2014

Re: No Throttling - really?

Quote from: ejs
If your MTU is 1300, that seems unnecessarily small, which probably won't be helping.
As for the TCP window size, I don't think wireshark can display the actual size if it didn't capture when the connection was initially established (with the window scaling factor).

Not sure about how or why the MTU is 1300 - according to the router, it should be 1492.
Your point about Wireshark and it knowing about the Actual Window Size is very useful. Since the original backup has now finished and its diff started, I restarted it with WireShark already running to get a more accurate picture.
At first it said 4xx/KBs but then dropped back until it has exactly 256KB/s again.  Sad
Community Gaffer
Community Gaffer
Posts: 5,286
Thanks: 612
Fixes: 5
Registered: ‎04-04-2007

Re: No Throttling - really?

We'll have a look on Monday.  It shouldn't be us.
Kelly Dorset
Broadband Service Manager