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Upgrading to Technicolor TG582n has downgraded speed?

mplusnetuser
Grafter
Posts: 103
Registered: 03-02-2011

Upgrading to Technicolor TG582n has downgraded speed?

I was switched to ADSL2+ on 7th Sept, when the old SpeedTouch 516 connected at 8,610, creeping up to 9,831 during DLM retraining, and settling on 9,025, where it stayed solidly for 6 weeks until my ethernet port died.
After a week of very low (4,540) connections on a temporary Voyager USB modem, I installed the new TG582n, and started re-training again. Connections went from 8.011 to 8.363 and down to 8.299, where it remains, now that retraining has just finished.
So the sparkling new TG582n appears to connect consistently slower than the ancient SpeedTouch 516?
And actual download speeds seem to be even worse. With the SpeedTouch I got  >8MB, while the TG582n is limited to <6MB (presumably because my IP Profile is now 7.32Mbps : I don't know what it was before). PlusNet's page says "Current line speed: 7.1 Mb"
I realise there are many potential causes other than how BT likes the TG582n, including possibly my replacement ethernet port. But still Sad
These are my current stats :-
BT Performance Test
-----------------------------
1. Best Effort Test: Download  Speed 5.92 Mbps

[0 Mbps-7.15 Mbps Max Achievable Speed]
IP Profile for your line is - 7.32 Mbps
2. Upstream Test: Upload Speed 0.15 Mbps

[0 Mbps-0.45 Mbps Max Achievable Speed]
Upstream Rate IP profile on your line is - 0.45 Mbps
TG582n Router stats
----------------------------
DSL Connection
DSL Type: ITU-T G.992.5
Bandwidth (Up/Down) [kbps/kbps]: 443 / 8.299
Output Power (Up/Down) [dBm]: 12,4 / 0,0
Line Attenuation (Up/Down) [dB]: 17,5 / 35,5
SN Margin (Up/Down) [dB]: 26,4 / 6,1
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): -
Error Seconds (Local/Remote): 6.156 / 0
FEC Errors (Up/Down): 0 / 0
CRC Errors (Up/Down): 0 / 41.118
HEC Errors (Up/Down): 0 / 41.439
And these are the SpeedTouch stats just after the ADSL2+ switch (I don't have a record of what my IP Profile or LIne Speed was) :-
- DSL Type: G.992.5 annex A
- Bandwidth (Up/Down) [kbps/kbps]: 444 / 9,025
- Line Attenuation (Up/Down) [dB]: 17.0 / 34.5
- SN Margin (Up/Down) [dB]: 27.0 / 4.5

I don't understand what it all means, but is that change in SN Margin from 4.5 to 6.1 significant?
How can I get back my lost 2MB (or more!), please?
(N.B. my wiring is as good as it's going to get in this old house, and hasn't changed recently, unlike my download speeds)
46 REPLIES
Plusnet Help Team
Plusnet Help Team
Posts: 13,401
Thanks: 243
Fixes: 68
Registered: 27-04-2007

Re: Upgrading to Technicolor TG582n has downgraded speed?

Hi there,
Just to cover the most important and obvious thing first, are you testing the speeds via wireless or ethernet (I'm guessing the latter but want to make sure).
Also do you still have the USB modem and if so what are speed test results looking like when you've tried that?
Adam
If this post resolved your issue please click the 'This fixed my problem' button
 Adam Walker
 Plusnet Help Team
mplusnetuser
Grafter
Posts: 103
Registered: 03-02-2011

Re: Upgrading to Technicolor TG582n has downgraded speed?

Hi Adam. I'm only using ethernet, and have turned off wireless completely.
I still have both the BT Voyager 105 USB modem, and the SpeedTouch ST516, but haven't used either since retraining with the TG582n started. When I had to use the USB modem (after we thought the SpeedTouch had failed, and before the TG582n arrived), it was only connecting at 4,540. Is there any point in trying it now? Is it even ADSL2+ compatible?
mplusnetuser
Grafter
Posts: 103
Registered: 03-02-2011

Re: Upgrading to Technicolor TG582n has downgraded speed?

I'm now out for the afternoon. But please keep the suggestions/analysis coming ...
From reading here, it seems you (PlusNet) could change the SN Margin to boost speeds, at the possible expense of less stability: is that right? Presumably that's reversible, if it goes badly? If so, let's do that to crank up the speed as far as feasible, please, on the suck it and see principle.
Any other possible actions?
mplusnetuser
Grafter
Posts: 103
Registered: 03-02-2011

Re: Upgrading to Technicolor TG582n has downgraded speed?

Uh, thanks for all those suggestions ... Wink
I still don't really understand all this stuff, but I've been searching here some more, and this is what I presume :-
1.  I have a stable connection (uptime over 4 days and counting since DLM retraining finished, and it's been months at a time in the past).
2.  I currently have an unusually high (for me) SNR (6.1 compared to 4.5 when I was switched to ADSL2+, and I think it's been even lower than that: 3 rings a bell, though I'm not sure).
3.  As a result, my connection and download speed is unusually low (for me).
So, unless I've got this badly wrong (and I'd welcome and confirmation, disagreement or comments), would Adam (or someone else from PlusNet) please lower my SNR to as low as feasible?
Thanks
Community Gaffer
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Registered: 04-04-2007

Re: Upgrading to Technicolor TG582n has downgraded speed?

Quote from: mplusnetuser
... would Adam (or someone else from PlusNet) please lower my SNR to as low as feasible?

I'll pick this up now for you ...
Edit: Done. Let me know how you get on because it may need a profile tweak this side when the change comes into effect.

Bob Pullen
Plusnet Product Team
If I've been helpful then please give thanks ⤵

mplusnetuser
Grafter
Posts: 103
Registered: 03-02-2011

Re: Upgrading to Technicolor TG582n has downgraded speed?

Great, thanks Smiley.
So what happens next, and when?
Community Gaffer
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Re: Upgrading to Technicolor TG582n has downgraded speed?

I'd give it an hour or two.

Bob Pullen
Plusnet Product Team
If I've been helpful then please give thanks ⤵

mplusnetuser
Grafter
Posts: 103
Registered: 03-02-2011

Re: Upgrading to Technicolor TG582n has downgraded speed?

Thanks. Do I need to reconnect, or reboot the router, in a couple of hours?
mplusnetuser
Grafter
Posts: 103
Registered: 03-02-2011

Re: Upgrading to Technicolor TG582n has downgraded speed?

Well, I left it two and a half hours, then rebooted the router. Nothing much has happened.
From 4 days ago, the SNR has only moved from 6.1 to 6; the connection from 8.299 to 8.446; the  IP Profile from 7.32 to 7.45 Mbps; the download speed from 5.92 to 6.05 Mbps; and the line speed is still at 7.1
Did I reboot the router too soon? Or did the SNR reduction get lost somewhere?
mplusnetuser
Grafter
Posts: 103
Registered: 03-02-2011

Re: Upgrading to Technicolor TG582n has downgraded speed?

Still nothing. Presumably that's it for the weekend. Pretty disappointing.
Community Veteran
Posts: 19,101
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Registered: 31-08-2007

Re: Upgrading to Technicolor TG582n has downgraded speed?

If you could post your current modem/router ADSL stats,. Also the results of a BT Speedtester (Diagnostics) and your Current Line speed (Login required) that will help us judge what is going on.
Also tell us if you are plugged into a Master Socket like the one on the LHS, or an extension socket, and are using Microfilters that look like this?
If you have extension sockets, how many and is everything that is plugged into them connected by filters?
Can you hear any crackling or other noises on the line when using the phone? Have you had any problems with incoming or outgoing calls?
mplusnetuser
Grafter
Posts: 103
Registered: 03-02-2011

Re: Upgrading to Technicolor TG582n has downgraded speed?

Quote from: Anotherone
If you could post your current modem/router ADSL stats,. Also the results of a BT Speedtester (Diagnostics) and your Current Line speed (Login required) that will help us judge what is going on.

Thanks, Anotherone. I've actually posted that info twice already in this topic, plus one set from before this router was installed (as a comparison). Here's the latest, after a router reboot an hour or so ago :-
DSL Connection				
Uptime: 0 days, 1:23:14
DSL Type: ITU-T G.992.5
Bandwidth (Up/Down) [kbps/kbps]: 443 / 8.295
Data Transferred (Sent/Received) [MB/MB]: 12,29 / 187,32
Output Power (Up/Down) [dBm]: 12,5 / 0,0
Line Attenuation (Up/Down) [dB]: 17,5 / 35,5
SN Margin (Up/Down) [dB]: 26,6 / 6,0
System Vendor ID (Local/Remote): TMMB / ----
Chipset Vendor ID (Local/Remote): BDCM / 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): -
Error Seconds (Local/Remote): 28 / 0
FEC Errors (Up/Down): 0 / 0
CRC Errors (Up/Down): 0 / 32
HEC Errors (Up/Down): 0 / 158

1. Best Effort Test:
Download speed achieved during the test was - 5.87 Mbps
For your connection, the acceptable range of speeds is 2 Mbps-7.15 Mbps.
IP Profile for your line is - 7.32 Mbps
2. Upstream Test:
Upload speed achieved during the test was - 0.31Mbps
Upstream Rate IP profile on your line is - 0.45 Mbps

Current line speed:  7.3 Mb

Each set with the TG582n is very similar, and distinctly worse than the prior consistently better results with the SpeedTouch ST516. Either because of the TG582n, or coincident with its installation (which itself followed a week of disruption because of using an ancient USB modem).
Quote from: Anotherone
Also tell us if you are plugged into a Master Socket like the one on the LHS, or an extension socket, and are using Microfilters that look like this?
If you have extension sockets, how many and is everything that is plugged into them connected by filters?
Can you hear any crackling or other noises on the line when using the phone? Have you had any problems with incoming or outgoing calls?

I'm (unavoidably) plugged into an extension socket, with a PlusNet-supplied rat's tail microfilter. The house pre-dates Master and Test sockets, but doesn't have a bell-wire. There is one other extension, for a phone, using a microfilter. The BT Quiet Line test is silent; phone calls are perfectly fine; and unplugging everything but the router makes no difference. I've often gone for months without any router disconnections. Short of re-wiring, I think it's as good as it's going to get.
But since installing the TG582n, the SN Margin seems to have increased from 4.5 (or lower) to 6.0 (or higher), and I understood that Bob Pullen was going to reduce it last Friday, which he said would take "an hour or two" (to happen, or to show results: I don't know).
Either there has been some glitch, or I have misunderstood what's supposed to be happening. What do you think?
Community Gaffer
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Re: Upgrading to Technicolor TG582n has downgraded speed?

I did request the change. Whether it's worked, or was applied and has since been reverted by BT Wholesale's DLM systems I don't know.
For good measure I've requested the change again, although I'm not convinced it's necessarily the best thing to do. Your line is definitely disconnecting on occasion:
Session Started	Session Ended	Session Duration
03:58 26/Nov/2012 N/A   10:54:19 (on going)
05:09 25/Nov/2012 03:55 26/Nov/2012   22:46:29
05:07 25/Nov/2012 05:09 25/Nov/2012   0:1:27
05:06 25/Nov/2012 05:07 25/Nov/2012   0:0:44
05:05 25/Nov/2012 05:06 25/Nov/2012   0:1:38
05:03 25/Nov/2012 05:04 25/Nov/2012   0:1:24
04:39 25/Nov/2012 05:03 25/Nov/2012   0:24:3
04:37 25/Nov/2012 04:39 25/Nov/2012   0:1:32
04:20 25/Nov/2012 04:37 25/Nov/2012   0:17:33
04:18 25/Nov/2012 04:20 25/Nov/2012   0:1:46
03:55 25/Nov/2012 04:18 25/Nov/2012   0:23:10
11:15 24/Nov/2012 03:54 25/Nov/2012   16:39:37

CRC and HEC errors are bad too. The lack of FEC errors also suggests interleaving's switched off on your line. I'd suggest we switch it on but that will lower your sync speed a little too which I guess is what you're trying to avoid? As you're significantly above the magic ~4Mbps required for HD streaming, I'd be happy with stability over weaning the extra yard or two out of the sync speed.
Different chipsets in the routers might help explain why one seems faster than the other although AFAIK both the Speedtouch and the Thomson should be using a Broadcom chipset. The Thomson definitely is:
Chipset Vendor ID (Local/Remote):	BDCM / IFTN

Bob Pullen
Plusnet Product Team
If I've been helpful then please give thanks ⤵

Community Veteran
Posts: 19,101
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Registered: 31-08-2007

Re: Upgrading to Technicolor TG582n has downgraded speed?

Hi mplusnetuser,
As Bob has said Target SNRM changes don't always take and sometimes have to be repeated, whether it's worked this time remains to be seen.
You should not need to reboot, in fact a note of caution, repetitive rebooting will be seen by the exchange DLM as a dropping connection and that may cause the Target SNRM to be raised or the sync speed banded. As would high error rates.
Whilst I appreciate that you had already posted some stats etc. conditions do/can change with time and the reason for asking for current stats is to see which of the stats has changed. As the 582n stats that you posted initially don't state the uptime one can't make any deductions about errors, except that perhaps they aren't unduly high otherwise DLM would have turned on Interleaving automatically. This is also indicated in the latest stats.
Looking at the stats that you have posted suggests a certain degree of consistency which is perhaps a good thing, however the figures suggest things are not performing as well as one might have hoped. This has nothing to do with which modem/router is being used.
As you rightly observed when the Speedtouch was syncing about 9mbps, the Noise Margin was around 4.5db, but had you resynced at that time the speed would gave dropped as the margin at resync is set to the Target value.
This means that at the time the 9Mbps sync speed was achieved Noise conditions would have been less (as the sync would still have occurred with a 6db Target) and then subsequently the noise has increased, reducing the margin. So there is actually nothing wrong with the way the 582n is performing on your line compared to the Speedtouch.
Now as Bob has hinted, with a lower Target SNRM, you will have a lower margin by definition,  and an increase in errors may result dependant on noise variation which could cause the DLM to find a 3dB Target impracticable . Also, if DLM sees what it thinks is a dropping connection raising the Target is the default to try and stabilise the situation.
As I think you appreciate, the standard of wiring as well as the condition and length of line to the exchange can influence the noise picked up, as well as the presence of the multitude of potential noise sources, locally and anywhere between you and the exchange.
Plugging into an extension socket isn't an issue per se, as long as the wiring is up to standard. The purpose of plugging into the Test socket in an NTE5a situation is to isolate the internal wiring to eliminate it from the cause of a potential problem. As you don't have one, we can only just simply check the wiring is the right standard.
You've mentioned there is no bell wire, so if you check the wiring at the rear of your master socket and the two extension sockets, you should find that you only have wires connected to terminals 2 & 5 throughout. The wiring colours should be Blue+white trace on 2 and White+blue trace on 5. You should also not be using any plug-in extension leads, if so please say where and between what  items.
But before you do that, you need to be careful that disturbing the sockets doesn't cause a drop of sync. Also we need to address all the session drops that Bob has highlighted in the early hours of the 25th and one on the 26th. If that was you doing things such as dropping your PPP Internet session via the modem/router interface (ie clicking Disconnect and then Connect - in the Internet box) so that you Gateway hopped then OK, if however you were rebooting, or not doing anything at all there would almost certainly have been a loss of sync as well session drop. That number, in that space of time would normally be sufficient for DLM to raise the Target Noise Margin or Band the sync speed or both!
So, in future, if you want to reboot including changing modem/router settings, or swap anything about - filters,sockets leads etc., the safest way is to drop the PPP Internet session by clicking Disconnect, pausing, then powering down the modem/router and waiting a few minutes before disconnecting from the line. Do what ever you need or want to do, change modem/router settings off-line etc and take at least 10 minutes before reconnecting to the line, and don't do it more than about 5 times in an hour and then leave it for the rest of the day.
Once you've resynced, you may need to click Connect to establish a new PPP session. I'd also suggest that you do it in daylight hours rather than after dark.
So post back about the wiring and any information about the session drops, and we might be able to offer further advice.