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Good synch but terrible speeds?

Bookworms
Grafter
Posts: 187
Registered: 13-11-2007

Good synch but terrible speeds?

A few days ago (around the time Plusnet announced some major work on the network) my internet connection became almost unusable.
At first I though it might be due to Thames water digging a big hole in the pavement outside, but I've been running routerstats and I don't see any obvious signs of REIN (I had a lot of REIN last year but that seems - touch wood - to have gone away).
My router is reporting good synch but browsing is horribly slow.
-------------------------------------------------
Btw speedtest results
[speedtest.btwholesale.com]
Best Effort Test: -provides background information.
Download  Speed
0.95 Mbps

0 Mbps 7.15 Mbps
Max Achievable Speed
Download speedachieved during the test was - 0.95 Mbps
For your connection, the acceptable range of speeds is 2 Mbps-7.15 Mbps.
IP Profile for your line is - 6.92 Mbps
2. Upstream Test: -provides background information.
Upload Speed
0.35 Mbps

0 Mbps 0.83 Mbps
Max Achievable Speed
Upload speed achieved during the test was - 0.35Mbps
Additional Information:
Upstream Rate IP profile on your line is - 0.83 Mbps
==========================================
Thomson Gateway
DSL Connection
Link Information

Uptime: 1 day, 0:10:58
DSL Type: G.992.5 annex A
Maximum Bandwidth (Up/Down) [kbps/kbps]: 1,108 / 8,392
Bandwidth (Up/Down) [kbps/kbps]: 1,111 / 7,844
Data Transferred (Sent/Received) [MB/MB]: 46.15 / 240.34
Output Power (Up/Down) [dBm]: 12.5 / 20.0
Line Attenuation (Up/Down) [dB]: 23.0 / 40.0
SN Margin (Up/Down) [dB]: 6.0 / 3.0
Vendor ID (Local/Remote): TMMB / IFTN
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 1,820 / 0
FEC Errors (Up/Down): 1,202,800 / 41,826,264
CRC Errors (Up/Down): 17,992 / 133,365
HEC Errors (Up/Down): 107 / 140,149
Pick a task...
---------------------------
The router is connected directly to a newish BTO faceplate.
Could it be a faulty router?
[Or is this a Plusnet-wide problem?
There seem to be a lot of reports of poor browsing/good synch in the various forums - I just noticed an almost identical thread was opened  before I started this one. Sad ]



23 REPLIES
Bookworms
Grafter
Posts: 187
Registered: 13-11-2007

Re: Good synch but terrible speeds?

TBB result
Community Veteran
Posts: 5,164
Thanks: 478
Fixes: 20
Registered: 10-06-2010

Re: Good synch but terrible speeds?

Those error counts are fairly high IF they are for the 24 hours and 10 minutes and IF they are reliable. The high CRC count doesn't really tally with the Error Seconds count and general expectations. The SN margin is also low. Are you sure there are no signs of REIN?
Bookworms
Grafter
Posts: 187
Registered: 13-11-2007

Re: Good synch but terrible speeds?

The REIN I experienced last year was very bad - it was completely knocking out most of the MW radio band , for one thing!
I haven't detected any obvious interference using the radio test for the last few months (and the speeds I'm getting now are worse than when I had obvious REIN).
I've attached a few recent routerstat graphs if it helps.
Bookworms
Grafter
Posts: 187
Registered: 13-11-2007

Re: Good synch but terrible speeds?

I should add that I did a 'soft' disconnect/reconnect of the router yesterday hoping to connect to a better gateway but it didn't exactly improve things!
Community Veteran
Posts: 5,164
Thanks: 478
Fixes: 20
Registered: 10-06-2010

Re: Good synch but terrible speeds?

The bitloading does look a bit strange, with the long flat section after tone 219. I think a more gradual drop in bits at higher tones, and fewer tones with only 2 or 1 bits at the top end, would be more typical.
If you are clocking up CRC errors at about 5 per second or higher (I'm not sure of the exact rate when it will become easily noticeable), that will be the cause of the slow throughput speed and poor web browsing. Sometimes a graph of the increase in CRC errors since the previous sample can be very useful in displaying the size and timing of the problem.
The high error rate would be some kind of line or interference or modem/router problem. Unless, perhaps the target SNR margin is 3, and that's just too low? Despite the low SNR margin, the speed is still below what could be expected for the attenuation, so it would have to be a below average quality line or an always noisy environment, if the target SNRM is actually 3.
It's a shame you didn't get a 582n in your previous thread, because Plusnet supply the Sagemcom 2704N now, which isn't as popular and apparently doesn't work with RouterStats.
Bookworms
Grafter
Posts: 187
Registered: 13-11-2007

Re: Good synch but terrible speeds?

Thanks for the reply.
I have to go out now but I might later try disconnecting again and switching off the router for a couple of hours or so before reconnecting again though I'm not sure if it's a good idea to disconnect again at this stage?
Community Veteran
Posts: 5,164
Thanks: 478
Fixes: 20
Registered: 10-06-2010

Re: Good synch but terrible speeds?

Disconnecting and re-connecting once shouldn't cause any particular problem, what may happen is that you'll re-connect at a lower line speed but have a more usable connection. The DLM might do something about the error rate at some time, but if you remain connected with a constant high error rate, the DLM might still take action after a while even if you never disconnect.
Superuser
Superuser
Posts: 12,515
Thanks: 3,817
Fixes: 25
Registered: 22-08-2007

Re: Good synch but terrible speeds?

For the attenuation, that synch rate is a bit low.
Is the line quiet. Dial 17070 option 2.
Bookworms
Grafter
Posts: 187
Registered: 13-11-2007

Re: Good synch but terrible speeds?

There seems to be some anomaly.
BT speedtester latest:  seems to contradict the TBB result:

BTw
25-09-2015  20:30
1. Best Effort Test: -provides background information.
Download speed achieved during the test was - 4.81 Mbps
For your connection, the acceptable range of speeds is 2 Mbps-7.15 Mbps.
IP Profile for your line is - 6.92 Mbps
2. Upstream Test: -provides background information.
Upload Speed 0.71 Mbps

Max Achievable Speed 0.83 Mbps
----------------------------

-----------------------
Thomson Gateway stats @ 20:40:
DSL Connection
Link Information

Uptime: 1 day, 7:19:34
DSL Type: G.992.5 annex A
Maximum Bandwidth (Up/Down) [kbps/kbps]: 1,108 / 8,316
Bandwidth (Up/Down) [kbps/kbps]: 1,111 / 7,844
Data Transferred (Sent/Received) [MB/MB]: 59.14 / 271.96
Output Power (Up/Down) [dBm]: 12.5 / 20.0
Line Attenuation (Up/Down) [dB]: 23.0 / 40.0
SN Margin (Up/Down) [dB]: 5.5 / 3.0
Vendor ID (Local/Remote): TMMB / IFTN
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 4 / 0
FEC Errors (Up/Down): 1,369,933 / 51,622,064
CRC Errors (Up/Down): 25,745 / 173,163
HEC Errors (Up/Down): 252 / 182,565
-----------------
I tend to believe the TBB result as most sites are still like treacle.
Hmm, I think I will disconnect/ reconnect in a minute.
Bookworms
Grafter
Posts: 187
Registered: 13-11-2007

Re: Good synch but terrible speeds?


Well, I reconnected - didn't exactly help!
----------------------------------------------------
speedtest.btwholesale.com
1. Best Effort Test: -provides background information.
Download speedachieved during the test was - 0.84 Mbps
For your connection, the acceptable range of speeds is 2 Mbps-7.15 Mbps.
IP Profile for your line is - 6.77 Mbps
2. Upstream Test: -provides background information.

Upload speed achieved during the test was - 0.43Mbps
Additional Information:
Upstream Rate IP profile on your line is - 0.83 Mbps
--------------------------

Sad
Bookworms
Grafter
Posts: 187
Registered: 13-11-2007

Re: Good synch but terrible speeds?

Sudden improvement, though I don't know why:
Crazy
----------------------------------
BTw
1. Best Effort Test: -provides background information.

Download speed achieved during the test was - 6.57 Mbps
For your connection, the acceptable range of speeds is 2 Mbps-7.15 Mbps.
IP Profile for your line is - 6.77 Mbps
2. Upstream Test: -provides background information.

Upload speed achieved during the test was - 0.67Mbps
Additional Information:
Upstream Rate IP profile on your line is - 0.83 Mbps
-------------------------------


Bookworms
Grafter
Posts: 187
Registered: 13-11-2007

Re: Good synch but terrible speeds?

Quote from: Townman
For the attenuation, that synch rate is a bit low.
Is the line quiet. Dial 17070 option 2.

It was quiet when I tried it earlier.
Bookworms
Grafter
Posts: 187
Registered: 13-11-2007

Re: Good synch but terrible speeds?

Speed dropped again, though synch remains good:
BTw
---------------------------
1. Best Effort Test: -provides background information.

Download speedachieved during the test was - 0.94 Mbps
For your connection, the acceptable range of speeds is 2 Mbps-7.15 Mbps.
IP Profile for your line is - 6.06 Mbps
2. Upstream Test: -provides background information.
Upload speed achieved during the test was - 0.61Mbps
Additional Information:
Upstream Rate IP profile on your line is - 0.83 Mbps
-------------------
No disconnects or anything obvious in routerstats (to my untrained eye, at least).
Bizarre.
Undecided
Community Veteran
Posts: 5,164
Thanks: 478
Fixes: 20
Registered: 10-06-2010

Re: Good synch but terrible speeds?

I expect you'll see some packet loss running ping commands, with more packet loss for larger packets:
ping -n 50 212.159.6.9
ping -n 50 -l 1400 212.159.6.9
The problem is visible from the large CRC and HEC error counts in the stats.
The low BT speedtester results should make it fairly easy for a slow speed broadband fault to be accepted, although if it were me, I would try another modem/router first. Or you could just raise a fault to get a line test done, to see if the line test shows some obvious problem for Openreach to fix.