Your opinions on why my broadband sync speed has halved?

Hi there. I would like some opinions on this if possible. My trouble began last week with my LLU broadband connection, I am unsure exactly what day but it was possibly Tuesday. I was surfing the net, and it seemed like the Internet "got stuck" (pages wouldn't load even though I was connected to the net). Rebooting the computer I was using didn't fix it so I assumed it was an issue with the router or the actual connection, so I just rebooted the router.

It came back online and everything worked again. However some time late I noticed the sync speed was over half of what it used to be. I have a particularly long line here, and the max sync speed I can get is around 2mbit, Usually I was seeing roughly 2mbit or 1.9mbit downstream sync speeds and 0.6mbit upstream sync. It's been like this for years and I've been happy with it. After this issue arose though the downstream had gone down to 0.7mbit.

I've since raised the issue with ISP and after all their usual checks they can't find anything wrong with my line and a BT engineer has even reset my line at the exchange (or something to that effect) with no change to my sync speeds. They say that no one can find any faults with the line remotely, so the only option I have left is to have a BT engineer come out and check the line at the property.

What I don't get here is though, despite doing all the standard checks to see if there is a problem with my equipment, I can't find any problem. Now the support guy I've been talking to says my only option is to have a BT engineer visit my property to do some checks to see if there are any faults. However apparently if no faults are found BT may very well charge me a call out fee, he then went into explaining how I can dispute this if it happens (almost as if he expects it will happen).

I've tried two different routers and they both suffer the same low sync speeds, I've tried all the usual checks, different filters, reseting the routers to factory defaults etc etc. Nothing has worked. I even tried dialling 17070 and doing the quiet line test and it seemed quiet enough.

However the odd thing about all this is, my main router is a Billion Bipac 7800N - it allows you to alter the SNR values for the line (all be it via a hidden menu). Thinking outside the box, after this issue arose (but before I contacted my ISP about it), one night I tried altering the SNR on the router and amazingly, I was able to manually increase the line speed to 1.3Mbit, though it didn't seem to want to connect to my ISP at that speed (though maybe if I'd left it long enough it would have after a few hours). That's still a lot less than what I usually got but I couldn't improve it any more than that, otherwise it just wouldn't sync at all.

The support guy however seemed to ignore this at first and then second time round seemingly assumed I meant I'd done this altering prior to the speed dropping on my line and appeared to blame it for the fault (I didn't bother to correct him). I can't help but wonder if there's something glaringly obvious being missed here. Perhaps I'm utterly wrong, but if I can get the line speed up by altering the SNR then surly that means the fault is to do with something screwing up the line SNR?

Edited by deleted (Wed 06-Nov-13 15:54:59)

Set your target SNR to 6dB - the standard level.

Power off the router - so it will tell the DSLAM it is shutting down and is not a fault/disconn. Then disconnect the router from the socket.

Leave it off and disconnected for a reasonable time - I would suggest 30 to 40 minutes. Reboot the router and once it is up and running reconnect to the socket.

You will now have a clean, standard connection. Find all of your stats, Atten, SNR, SyncSpeeds and error counts and post those here.

What are you router stats? And do you have to have a set before the drop in speed.

In reply to a post by MHC:

Set your target SNR to 6dB - the standard level.

Power off the router - so it will tell the DSLAM it is shutting down and is not a fault/disconn. Then disconnect the router from the socket.

Leave it off and disconnected for a reasonable time - I would suggest 30 to 40 minutes. Reboot the router and once it is up and running reconnect to the socket.

You will now have a clean, standard connection. Find all of your stats, Atten, SNR, SyncSpeeds and error counts and post those here.

Right, well my new router (which isn't really new, two years old now) during this rebooting and what not, the wifi stopped working. Having checked up on that it appears my unit has fallen foul of a commonish problem with the 7800N where by the wifi card inside it burns out. Just my luck - seeing as my entire network is wireless that renders my 7800N useless to me, but at any rate I carried out this task using a laptop and ethernet.

I couldn't for some reason get the router to sync on default settings, however according to my old router (the 3com, which does still have wifi luckily) my SNR was 9db, so I went back to the 7800N and did what you said with that in mind, altered the SNR, reset it then unpluiged the adsl, left it for an hour, turned it back on and plugged it back in after it had booted up.

Now it did sync, but something else has come up; it refuses to connect to my ISP. Keeps saying in the log that it failed to raise MTU to 1500 and on the odd occasion it'll complain of an authentication error (which there shouldn't be because I haven't touched the settings for my ISP from when it was working).

Annnnnyway... Like I said it did sync and these are it's stats:

Text

1 23 45 67 89

DSP Firmware Version� � � � � � � � � � A2pB025f.d22k DMT Status� � � � � � � � � � � � � � � No DefectOperational Mode� � � � � � � � � � � � ADSL2+ Upstream� � � � � � � � � � � � � � � � 664Downstream� � � � � � � � � � � � � � � 713 SNR Margin(Upstream)� � � � � � � � � � 6.0SNR Margin(Downstream)� � � � � � � � � 7.3 Line Attenuation(Upstream)� � � � � � � 29.5Line Attenuation(Downstream)� � � � � � 66.0

I couldn't obtain any error/defect information because as I say it refuses to connect to my ISP and it seems it only records this information when connected (unless I was looking in the wrong place).

Just FYI; I did tweak the SNR again prior todoing what you asked, the maximum I could get out of it was yet again 1.3mbit, but I had to lower the SNR to zero to get there... Which is more than likely why it wouldn't connect to my ISP (again) even though it synced. Maybe not though... I don't know why it's not connecting now, if the wifi has gone down the crapper then maybe the whole router has started to fail simultaneously. At any rate these are the stats for it at 1.3mbit:

Text
1 23 45 67 89	DSP Firmware Version � � � � �A2pB025f.d22k DMT Status � � � � � � � � � �No DefectOperational Mode � � � � � � �ADSL2+ Upstream � � � � � � � � � � �667Downstream � � � � � � � � � �1344 SNR Margin(Upstream) � � � � �5.6SNR Margin(Downstream) � � � �0.0 Line Attenuation(Upstream) � �29.4Line Attenuation(Downstream) �65.5

As for my old router, since as I say my network is wireless I've had to revert to using that instead now, permenantly, until I can obtain a new router (the 3com is OK but it's circa 2008 and isn't too healthy on these more modern adsl long lines. 3Com also got swallowed up by HP back in 2010 and as such the router hasn't seen any firmware revisions since then). I get regular line drops with this router, which is why I upgraded to the billion in the first place that has up until just now worked perfectly for the whole two and a half years I've used it.

Anyway the 3com stats are as follows (seems to display more information than the billion does with or without an actual ISP connection active, again I'm not sure if I was just looking in the wrong place on the billion router):

Text

1 23 45 67 89 1011 1213 1415 1617 1819 2021 2223

Status � � � � � � � �     Configured � � � CurrentLine Status � �     --- � � � � � �  SHOWTIME Link Type � � �     --- � � � � � �  Interleaved Path  Data RateStream Type � �     Actual Data Rate Up Stream � � �     643 (Kbps.)Down Stream � �     665 (Kbps.)  Operation Data�     Upstream� � � � � Downstream Noise Margin� � � � 6 dB� � � � � � � 9 dBAttenuation � � � � 71 dB � � � � � � 58 dB �Defect Indication Indicator Name� � � � � � � � � � � � Near End Indicator � � � �Far End IndicatorFast Path FEC Correction� � � � � � � 0� � � � � � � � � � � � �0 Interleaved Path FEC Correction � �   0� � � � � � � � � � � � �7668Fast Path CRC Error � � � � � � � � � 0 � � � � � � � � � � � � 0 Interleaved Path CRC Error� � � � � � 0 � � � � � � � � � � � � 2Loss of Signal Defect � � � � � � � � 0 � � � � � � � � � � � � --- Fast Path HEC Error � � � � � � � � � 0 � � � � � � � � � � � � 0Interleaved Path HEC Error� � � � � � 0 � � � � � � � � � � � � 0

In reply to a post by MrSaffron:

What are you router stats? And do you have to have a set before the drop in speed.

Unfortunately I don't have any stats from prior to the issue, I've been with this ISP now for about three years and this is the first issue I've had while being with them, so I've never really been in the frame of mind to keep a record of the line stats.

Here's another set of stats from my 3com router having left it alone for a few hours.

Text

1 23 45 67 89 1011 1213 1415 1617 1819 2021 2223

Configured� � � Current Line Status � � --- � �         SHOWTIMELink Type � � � --- � �         Interleaved Path  Data Rate Stream Type � � Actual Data RateUp Stream � � � 643 (Kbps.) Down Stream � � 665 (Kbps.)  Operation DataOperation Data� Upstream� � � � Downstream Noise Margin� � -15 dB�         4 dBAttenuation � � 71 dB �         58 dB �Defect Indication Indicator Name� N               ear End Indicator� � � Far End IndicatorFast Path FEC Correction� � � � 0 � � �                0 Interleaved Path FEC Correction 0 � � �                2021725Fast Path CRC Error � �         1 � � �                0 Interleaved Path CRC Error� � � 0 � � �                19153Loss of Signal Defect �         0 � � �                --- Fast Path HEC Error � �         0 � � �                0Interleaved Path HEC Error� � � 0 � � �                0

At your attenuation you could well be better off not using ADSL2+ but ADSL2 or G.DMT.

I don't know for sure but I think I've been using ADSL2+ for years, ever since Tiscali (yes, years ago I used to be a Tiscali customer, though I did eventually switch to UKOnline - and then from UKO to my current ISP) moved me to LLU. It's the only way I've been able to achieve up to 2mbit line speeds as far as I know.

So why not try ADSL2 & G.DMT modes in your router and see if it goes faster?

Edited by XRaySpeX (Fri 08-Nov-13 13:34:49)

Well I moved back to the billion and set it up as the modem and dhcp server and the 3com as just a wireless hub, so I tried it changing modulation; it won't sync at all with just ADSL2 and using only G.Dmt causes it to sync at the same low levels as before. Now though if I put it on just ADSL2+ it syncs at nearly 1mbit, it connects to my isp too, but no web pages work, ike i have no connection.

In reply to a post by anphrax:

but no web pages work, like i have no connection.

What's log say?

Check or change DNS.

Do pages load if you use IP addys instead of URLs? E.g. ping 80.249.99.130 for TBB.