Drop in Speed

Hello,

So I happen to run a speed test the other day on the BT wholesale website, I was initially getting about 72mbps but the new speed test shows I was getting around 40mbps. I contacted BT and they have said there is nothing wrong their end. I am a loss as to what the issue is.

I have an ASUS router connected to an OpenReach modem.

Thinks I have tried:

- Reset modem
- Reset router back to factory settings
- Connected computer directly to the router (its currently connection to switch).
- Connected computer directly to OpenReach modem (setup a PPOE connection).
- Disconnecting everything except my computer on the network.

Here are some stats from the OpenReach modem.

==
# xdslcmd info --pbParams
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Max: Upstream rate = 37093 Kbps, Downstream rate = 98092 Kbps
Path: 0, Upstream rate = 19999 Kbps, Downstream rate = 79999 Kbps

Discovery Phase (Initial) Band Plan
US: (0,95) (868,1207) (1972,2783)
DS: (32,859) (1216,1963) (2792,3971)
Medley Phase (Final) Band Plan
US: (0,95) (868,1207) (1972,2783)
DS: (32,859) (1216,1963) (2792,3971)
VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 37093 kbps 98092 kbps
Actual Aggregate Tx Power: - 0.3 dBm 12.4 dBm
============================================================================
VDSL Band Status U0 U1 U2 U3 D1 D2 D3
Line Attenuation(dB): 2.7 13.5 19.8 N/A 7.5 16.2 24.3

Signal Attenuation(dB): 2.7 12.6 18.7 N/A 7.5 16.2 24.3

SNR Margin(dB): 23.7 23.0 23.2 N/A 6.6 6.6 6.6

TX Power(dBm): -14.8 -30.2 -0.5 N/A 8.1 7.8 7.1

# xdslcmd info --show
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Max: Upstream rate = 37069 Kbps, Downstream rate = 98092 Kbps
Path: 0, Upstream rate = 19999 Kbps, Downstream rate = 79999 Kbps

Link Power State: L0
Mode: VDSL2 Annex B
VDSL2 Profile: Profile 17a
TPS-TC: PTM Mode
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 6.6 23.2
Attn(dB): 0.0 0.0
Pwr(dBm): 12.4 -0.3
VDSL2 framing
Path 0
B: 57 237
M: 1 1
T: 64 42
R: 16 16
S: 0.0231 0.3781
L: 25665 5374
D: 1339 1
I: 74 127
N: 74 254
Counters
Path 0
OHF: 1297322 363129
OHFErr: 0 0
RS: 249085501 2359794
RSCorr: 8183 0
RSUnCorr: 0 0

Path 0
HEC: 0 0
OCD: 0 0
LCD: 0 0
Total Cells: 221750189 0
Data Cells: 6251240 0
Drop Cells: 0
Bit Errors: 0 0

ES: 0 0
SES: 0 0
UAS: 19 19
AS: 1442

Path 0
INP: 3.00 0.00
PER: 1.10 3.97
delay: 8.00 0.00
OR: 151.73 64.47

Bitswap: 183 0
==

Open TaskManager (assuming you are using Windows) and select Networking tab.

Run a speedtest here and at speedtest.net one after the other. Grab a screenshot of Task Manager and host that on Flikr, photobucket, tinypic or similar.


Provide links to the test results and image ...

Hello,

Here you go:

http://i59.tinypic.com/2ekqgsk.png
http://i58.tinypic.com/oid655.png
http://i59.tinypic.com/j7dfso.png

Thanks
Sam

Can you widen the screen to get both on one and also ensure it is scaled so the full extent can be seen

And links to the actual test results?

Hello,

I thought it best to do a video instead so here it is:

https://www.screenr.com/fvtN

Results:
http://www.thinkbroadband.com/speedtest/results.html...
http://www.speedtest.net/my-result/4105434082

Thanks
Sam

Hello,

Its really strange because from what I read the stats from the modem look good unless I am missing something.

-Sam

In reply to a post by ansam:

Hello,

Its really strange because from what I read the stats from the modem look good unless I am missing something.

So it isn't a sync speed (and thus a noise/SNR) issue, it seems to be throughput that is problematic which points at something further into the network, backhaul or possibly ISP gateways.

Edited by rippedcotton (Sun 01-Feb-15 21:28:25)

Yep the stats look ok - have you always connected to the router the same way, i.e. it looks like a USB3 gigabit ethernet adapter?

Hello,

No its a new laptop. I have a hardwired desktop though and seeing the same sort of stats.

-Sam

In reply to a post by ansam:

Hello,

No its a new laptop. I have a hardwired desktop though and seeing the same sort of stats.

I wasn't saying that the problem is in your devices or network.

My opinion is that there is a limitation somewhere in the connection back from your exchange to your ISP. It could be down to backhaul congestion or even some sort of mis-configuration in equipment out of your control.

You need to do some speed tests that use the BT speed tester and also 3rd party ones and see if there is a difference in the throughput, that could help to identify where the problem lies.

In reply to a post by rippedcotton:

In reply to a post by ansam:

Hello,

No its a new laptop. I have a hardwired desktop though and seeing the same sort of stats.

I wasn't saying that the problem is in your devices or network.

My opinion is that there is a limitation somewhere in the connection back from your exchange to your ISP. It could be down to backhaul congestion or even some sort of mis-configuration in equipment out of your control.

You need to do some speed tests that use the BT speed tester and also 3rd party ones and see if there is a difference in the throughput, that could help to identify where the problem lies.

Hello,

I was responding to Phil. I am moving away from BT next week to TalkTalk perhaps that will reset the connection.

Now something is strange cause in my Son computer we are seeing 71MBps. So I am now trying to figure out why two other computers are only reporting between 41 - 51MBps.

Sam

Where are the rest of your stats, error rates ect ? My observations of your stats are that you are close to the FTTC cab, i would guess at around 200-300 mtrs away, or your D'side pair is made of a high gade of copper, I also can see that DLM oddly has interleaved your connection for some reason or other, but you still apear to be syncing at the full rate (as reported in your stats) this is very odd, and not possible imo , somethings not right with those stats

on another note do you have a ping monitor running , to see if you are getting packet loss ?

Edited by tommy45 (Sun 01-Feb-15 22:54:59)

In reply to a post by tommy45:

Where are the rest of your stats, error rates ect ? My observations of your stats are that you are close to the FTTC cab, i would guess at around 200-300 mtrs away, or your D'side pair is made of a high gade of copper, I also can see that DLM oddly has interleaved your connection for some reason or other, but you still apear to be syncing at the full rate (as reported in your stats) this is very odd, and not possible imo , somethings not right with those stats

on another note do you have a ping monitor running , to see if you are getting packet loss ?

Hello,

What do I need to run to get you the stats you need? Also would moving to a new provider reset this as I am moving to talktalk in s fortnight.

Thanks
Sam

Sam,

I asked about the hardware just to double check that there wasn't a bottleneck on your actual machine - I mentioned the USB adapter as I've never known them be super efficient - although for a gigabit speed one I would imagine you definitely need to plugged into a USB 3 port not a 2.0?

In my experience, its just worth checking all avenues before assuming the link to the outside world to be at fault (although it usually is!).

How is your son's computer connected?

Just a thought,

Phil

In reply to a post by phil_w73:

Sam,

I asked about the hardware just to double check that there wasn't a bottleneck on your actual machine - I mentioned the USB adapter as I've never known them be super efficient - although for a gigabit speed one I would imagine you definitely need to plugged into a USB 3 port not a 2.0?

In my experience, its just worth checking all avenues before assuming the link to the outside world to be at fault (although it usually is!).

How is your son's computer connected?

Just a thought,

Phil

Hello Phil,

My son's computer is hard wired with an internal Ethernet, BUT I also have another PC hard wired with internal Ethernet and it shows the same results as the laptop.

-Sam

A bit weird then!

All directly into the ASUS or the ethernet Switch?

No powerline plugs involved anywhere?

What modem are you using the HH5 ? or the BTopenreach Huawei modem ?
There are usually error stats at the lower part of the stats
The modem is reporting that your connection is interleaved yet it also is reporting that you are syncing at the full rate , something that i don't think is possible , because interleaving usually with steal around 10mbps due to the extra overheads for the error correction it needs
You can see that it's interleaved at the D Line D: 1339 1 if fast path it would be 1
and again INP: 3.00 0.00 is typical too , again would be 0.00 if fastpath
but yet your modem is reporting your sync speed as Path: 0, Upstream rate = 19999 Kbps, Downstream rate = 79999 Kbps will be lower so the 71mbps on theother pc's will be about right, as your sync will be around 72-73mbps and your ip profile around 73.5mbps
as to why you laptop is seeing lower throughput could be the wireless link unless you are using a ethernet cable
run the bt performance tester to get your IP profile
BTW PT run the speedtest then in the second part enter your telephone number (Further diagnostics)and click on the button to get your ip profile

Edited by tommy45 (Sun 01-Feb-15 23:30:05)

Hello,

Yes I am using the Openreach modem. The modem wasn't long rebooted so that may be why no errors...

# xdslcmd info --show
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Max: Upstream rate = 37140 Kbps, Downstream rate = 98312 Kbps
Path: 0, Upstream rate = 19999 Kbps, Downstream rate = 79999 Kbps

Link Power State: L0
Mode: VDSL2 Annex B
VDSL2 Profile: Profile 17a
TPS-TC: PTM Mode
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 6.6 23.2
Attn(dB): 0.0 0.0
Pwr(dBm): 12.4 -0.3
VDSL2 framing
Path 0
B: 57 237
M: 1 1
T: 64 42
R: 16 16
S: 0.0231 0.3781
L: 25665 5374
D: 1339 1
I: 74 127
N: 74 254
Counters
Path 0
OHF: 99893494 2613395
OHFErr: 14 3
RS: 1999681429 2004379
RSCorr: 601649 70
RSUnCorr: 675 0

Path 0
HEC: 197 0
OCD: 0 0
LCD: 0 0
Total Cells: 4189806406 0
Data Cells: 678197412 0
Drop Cells: 0
Bit Errors: 0 0

ES: 2 2
SES: 0 0
UAS: 19 19
AS: 111035

Path 0
INP: 3.00 0.00
PER: 1.10 3.97
delay: 8.00 0.00
OR: 151.73 64.47

Bitswap: 17108 8

#
IP Profile for your line is - 77.43 Mbps

Try xdslcmd info --stats With a # if it don't work without ,not sure why your IP profile is showing 77.43 if you really are interleaved maybe the modem is mis reporting but if you are on fast path and have the full sync then your max throughput should be somewhere around 74-75.5 mbps just another question do the results you see vary depending on the time of day or night ?
There are a couple of programes that will automate the logging of your modems stats and even a web gui that will allow you to view them even on some mobile devices

Edited by tommy45 (Mon 02-Feb-15 00:01:16)

# xdslcmd info --stats
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Max: Upstream rate = 37109 Kbps, Downstream rate = 98312 Kbps
Path: 0, Upstream rate = 19999 Kbps, Downstream rate = 79999 Kbps

Link Power State: L0
Mode: VDSL2 Annex B
VDSL2 Profile: Profile 17a
TPS-TC: PTM Mode
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 6.6 23.2
Attn(dB): 0.0 0.0
Pwr(dBm): 12.4 -0.3
VDSL2 framing
Path 0
B: 57 237
M: 1 1
T: 64 42
R: 16 16
S: 0.0231 0.3781
L: 25665 5374
D: 1339 1
I: 74 127
N: 74 254
Counters
Path 0
OHF: 101297886 3006445
OHFErr: 14 3
RS: 2269324552 1325291
RSCorr: 609833 71
RSUnCorr: 675 0

Path 0
HEC: 197 0
OCD: 0 0
LCD: 0 0
Total Cells: 134890543 0
Data Cells: 703329377 0
Drop Cells: 0
Bit Errors: 0 0

ES: 2 2
SES: 0 0
UAS: 19 19
AS: 112597

Path 0
INP: 3.00 0.00
PER: 1.10 3.97
delay: 8.00 0.00
OR: 151.73 64.47

Bitswap: 17332 8

Total time = 1 days 7 hours 16 min 56 sec
FEC: 609833 71
CRC: 14 3
ES: 2 2
SES: 0 0
UAS: 19 19
LOS: 0 0
LOF: 0 0
Latest 15 minutes time = 1 min 56 sec
FEC: 33 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
Previous 15 minutes time = 15 min 0 sec
FEC: 5733 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
Latest 1 day time = 7 hours 16 min 56 sec
FEC: 165863 11
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
Previous 1 day time = 24 hours 0 sec
FEC: 443970 60
CRC: 14 3
ES: 2 2
SES: 0 0
UAS: 19 19
LOS: 0 0
LOF: 0 0
Since Link time = 1 days 7 hours 16 min 35 sec
FEC: 609833 71
CRC: 14 3
ES: 2 2
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
#

Hello,

No results don't seem to vary on time of day. I've been trying it on off during the day and the evening.

You're looking at the wrong area, tommy

DLM has intervened downstream, but the sync speed remains at 80 Mbps because the line has a lot of spare capacity. The Max attainable is 98Mbps (although that is likely to be an overestimate), and the downstream SNR is still above 6dB.

DLM's intervention has turned on FEC and interleaving, and we can see it is working - there are only 14 CRC errors over the 30 hours of uptime, resulting in only 2 errored seconds. That's almost zilch ... and if kept up will see DLM de-intervening.

Whatever the cause of the horribly low speed, it isn't down to the modem connection to the cabinet.

Edit: a slight change to that analysis... The FEC count actually looks pretty high. If DLM de-intervened, that could end up being an ES count as high as 10,000 - which would cause DLM to re-intervene.

That doesn't change the fact that the FEC process is currently working, so the line throughput will be fine.

Edited by deleted (Mon 02-Feb-15 00:31:44)

Well there are several fields in your modems stats that say you are interleaved , imo the modems is miss reporting the stats or the IP profile hasn't updated if you log in to you router and disonnect to PPPOE session (not the modem) leave this off for say 30mins and reconnect and re test the bt performance tester and see if the ip profile has dropped or not, as sometimes they can get stuck
dropping the pppoe session will not have any effect on DLM, also another note should you ever need to power off your modem, leave powered off for 45min to 1 hr, so BT's DLM doesnt see it as a fault and apply more interleaving or banded profile

Well you learn something new every day, i assumed that dlm worked from the sync rate not the attainable, as mine has spare attainable and snr but it still clobbered me down to around 73mbps

Edited by tommy45 (Mon 02-Feb-15 00:16:56)

In reply to a post by WWWombat:

You're looking at the wrong area, tommy

DLM has intervened downstream, but the sync speed remains at 80 Mbps because the line has a lot of spare capacity. The Max attainable is 98Mbps (although that is likely to be an overestimate), and the downstream SNR is still above 6dB.

DLM's intervention has turned on FEC and interleaving, and we can see it is working - there are only 14 CRC errors over the 30 hours of uptime, resulting in only 2 errored seconds. That's almost zilch ... and if kept up will see DLM de-intervening.

Whatever the cause of the horribly low speed, it isn't down to the modem connection to the cabinet.

Hello,

Any ideas? Are you thinking it's something internal (home network).

-Sam

Well once to get down to device/hardware level it could be anything as i cannot see your hardware i don't know what software you have installed on it things like firewalls and security av suites , then if you cpu is near full load that could have a bearing on what speeds it's capable of , I don't use a laptop , but i once did some testing on one, and that was able to download at more or less full speed, although it did have problems sustaining it , wired of course

I know this is probably a silly question, but have you tried unplugging your son's network cable from his PC and then plug it in you laptop? i.e. you laptop is in the same room as your son's pc etc.

What speed on the speed test do you get there?

Paul.

Hi Sam,

It does look to be something internal on your network or individual machines...

I think you're son's laptop has pretty much prove that for you. As Tommy says, it could even be security software on the machines that is throttling the connection due to checking packets for nastiness?

Any iPads around that you could install one of the speedtest apps on, just for a comparison (although wireless connection speed would have to be decent)?

Phil

Edited by phil_w73 (Mon 02-Feb-15 00:34:18)