BT & Connectivity issues.

Kristoph

Kristoph

Kristoph

Soldato
Joined
11 May 2007
Posts
8,303
Okay, a bit of history.

Week or so ago, we notice line speed had dropped from about 10mbit to 2mbit.

We're on the BT Option 3 package, but it all of their packages I notice offer "Up to 20mbit" so that's the first problem.

Just checked at BT estimate we can receive up to 6.5mbit in our area now.


Secondly we start to get issues with the internet dropping and our BT vision box failing to start up (presumably because of the lack of internet).

I stripped everything out and had the router set up by itself, tested it with different filters, made sure the settings were correct and it still didn't work.

BT admitted to there being a fault at the exchange and said it would hopefully be fixed by Monday. Internet at this point is still very intermittent and working for short periods of time before losing connection for several hours.

Tuesday an Engineer comes out and tests our line, nothing at our end seemed to be at fault and he needed further equipment to be delivered to the exchange to test it further.

Move on to today, and we get a local call from the exchange to tell us they've changed over some equipment at the exchange and to test to see if the internet is back up - I restarted the router and connected using the router home page and it worked.

It's dropped a couple times since I got it connected but seems to be okay now.

I'm tempted to change the home hub router over to an MSI router I bought a year ago.


I guess my 3 questions are;

I presume BT do not have to give any speed in particular, now it's all "Up to 20mb" now?

Would the router losing its connection to the internet (whilst maintaining a local network) be an issue our end or BT's end?

And would it be worth me swapping over the router for an MSI one (was a cable/dsl router RG60SE i think?)


Thanks.
 
1: Correct
2: BT's probably, and they admitted as much.
3: Doubt changing the router would really make a great deal of difference, and yours wouldn't work anyway as you need an ADSL router...
 
If it is, or was, dropping out a lot DLM would probably step in and turn up the target SNR margin which would reduce the speed you got. In every case like this you need to post ADSL stats or trying to work out what's wrong is guesswork.
 
Not sure if this is helpful at all..


DSL Connection

Link Information

Uptime: 0 days, 22:24:00

Modulation: G.992.5 annex A

Bandwidth (Up/Down) [kbps/kbps]: 1,170 / 3,023

Data Transferred (Sent/Received) [MB/GB]: 146.91 / 1.82

Output Power (Up/Down) [dBm]: 12.5 / 0.0

Line Attenuation (Up/Down) [dB]: 10.5 / 21.0

SN Margin (Up/Down) [dB]: 7.0 / 27.0

Vendor ID (Local/Remote): TMMB / IFTN

Loss of Framing (Local/Remote): 0 / 0

Loss of Signal (Local/Remote): 2 / 0

Loss of Power (Local/Remote): 0 / 0

Loss of Link (Remote): 0

Error Seconds (Local/Remote): 12 / 0

FEC Errors (Up/Down): 0 / 0

CRC Errors (Up/Down): 0 / 0

HEC Errors (Up/Down): 0 / 0

Line Profile: Fast
Click to expand...


Had no problems with the line since yesterday, just speed tests of 1.9-3 mbit
 
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You should see much higher than that. THere must be an issue with the line. You would expect a good 18-20meg on a decent LLU provider (O2, BE, Sky)
 
Chill a little bit :)

Kristoph has already detailed how the connection has been misbehaving recently, and that would account for some of the stats shown.

  • Modulation indicates ADSL2+.
  • Downstream output power is screwy, I'm assuming it's a firmware bug if you are online through that device with no problems.
  • SN Margins are fine on the upstream with a high margin on the downstream side due to the DLM process associated with connection issues. This high margin effects a much reduced sync rate.
  • You've had a couple 'Loss of Signal', probably modem re-syncs (as opposed to reboot).
  • The 'Error Seconds' seem a little peculiar given that there are no 'CRC Errors'. Possibly related to modem re-sync; I wouldn't be worried.
  • 'Line Profile: Fast' may indicate that interleaving is turned off on upstream side (which I think is more typical) or on both up-and downstream (which would account for zero 'FEC Errors').
The fact there are no errors at all indicates the connection is very good. I'm somewhat surprised the BT system is holding you at a 3 Mbps sync.
 
Thanks for looking over that ncjok, I don't understand everything you've talked about but I understand that my end seems to be fine, and the line seems capable of faster than 3Mbps.

Worth calling BT again?


I've just been testing my 3G speed on my phone.

BT Line =

United States server.

1.68 mbps [1672 kbps | 209 kBps]
Latency: 213 ms
Test Time: 9.49 secs
Test Device: Windows Vista


Mobile phone - T-Mobile

2.05 mbps [2048 kbps | 256 kBps]
Latency: 864 ms
Test Time: 16.14 secs
Test Device: Linux
 
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Well there are three approaches I would be considering if I were in your position,

  • Power cycle the device now and, upon connection, immediately check the stats to see if the (target) downstream SN Margin has been reduced from 27 dB. If it has, the sync rate should also have improved from 3 Mbps.
  • Sit tight for a while and see if BT's system decides your connection is good and causes a re-sync with improved stats as discussed in the point above. *
  • Ring the ISP as you suggested and query being held at a "low speed".
* I do not know how long BT's DLM process takes to effect a positive change in the connection speed. Hopefully someone can clarify this.
 
Kristoph said:
Not sure if this is helpful at all..





Had no problems with the line since yesterday, just speed tests of 1.9-3 mbit
Click to expand...

I suggest you restart your modem and repost the stats, and also update the firmware.

22 hours uptime have you have no errors reported at all and the output power isn't reported. This suggests a fault in the router/firmware.

Also, your SN margin for your download is at 27dB. Should be roughly round 6dB.

Once you have restarted the router/update firmware, please repost the stats.

Thanks.
 
Okay, I've just restarted it.

Not sure if I got the details quick enough?

Link Information

Uptime: 0 days, 0:00:47

Modulation: G.992.5 annex A

Bandwidth (Up/Down) [kbps/kbps]: 730 / 2,541

Data Transferred (Sent/Received) [KB/KB]: 20.00 / 13.00

Output Power (Up/Down) [dBm]: 9.5 / 0.0

Line Attenuation (Up/Down) [dB]: 10.5 / 21.5

SN Margin (Up/Down) [dB]: 10.5 / 27.5

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): 0 / 0

FEC Errors (Up/Down): 29 / 0

CRC Errors (Up/Down): 32 / 0

HEC Errors (Up/Down): 10 / 0

Line Profile: Fast
Click to expand...
 
No positive change on restarting the hub. Lost half a meg on the downstream, which still appears to be on a 27 dB profile and there is indication that the upstream target has increased, probably to 9 dB, resulting in a decrease of upstream sync rate.

I found some indication in the BTCare forum that the hub should be left for up to 72 hours to recover from slow sync/DLM issues. Admittedly, this seemed a bit excessive to me; I was personally suprised it kept you at 27 dB for 22+ hours.

I see no harm in giving the ISP a call to clarify :)
 
Yeah, you should really phone the ISP and get them to reset that. Provided you leave the connection up, though (and a few drops a day is well within acceptable), it should start to happen automatically inside 3 days.
 
What exactly would I be asking them to reset? I don't really know what to ask.

Shall I leave the line for a few days and see if it's all the same, then phone?
 
Call up their tech support and ask for the 'DSLAM profile' to be reset. If you confuse the operator with this term it could be more generally referred to as the 'line profile'.

Ordinarily, well with the ISPs I'm more familiar with, this involves a quick adjustment on their part which should see your device disconnect and re-sync with the exchange equipment and that's it. With BT, however, I'm not sure whether following this change BT's DLM system monitors the connection in an ongoing fashion as it had previously been doing or whether the whole retraining process, where you should avoid powering off or rebooting the hub for up to ten days, is initiated. Maybe you could ask them and let me know for interest :)

If you don't get much joy on the telephone with BT India, you might be able to get the DSLAM profile changed by posting a thread in the BTCare forums.

Following the change you could also use the Broadband Performance Tester to periodically check your 'IP Profile'. I suggest this as it represents, in my opinion, another pitfall of BT's system and can on occasion slow your speed below that which your connection is capable of handling. Paste the results here if you wish us to review them, however it can take up to three days to reach an appropriate setting.
 
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Router was reset this morning.

Just did a check on the ADSL details, a few changes are highlighted in bold.

Link Information

Uptime: 0 days, 0:11:56

Modulation: G.992.3 annex A

Bandwidth (Up/Down) [kbps/kbps]: 1,191 / 6,677

Data Transferred (Sent/Received) [MB/MB]: 2.58 / 14.49

Output Power (Up/Down) [dBm]: 12.5 / 0.0

Line Attenuation (Up/Down) [dB]: 10.5 / 21.5

SN Margin (Up/Down) [dB]: 6.5 / 15.5

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): 0 / 0

FEC Errors (Up/Down): 0 / 0

CRC Errors (Up/Down): 0 / 0

HEC Errors (Up/Down): 0 / 0

Line Profile: Fast
Click to expand...


Also did a speed test on the bt site.


Download speed achieved during the test was - 1869 Kbps
For your connection, the acceptable range of speeds is 400-2000 Kbps.
Additional Information:
Assured Rate IP profile on your line is - 2000 Kbps
Click to expand...


Will phone BT soon to ask for the profile to be reset.
 
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Reset your connection, you're connected at ADSL modulation and not ADSL2+.

Your download SN Margin is still too high, but it seems to be coming down.

You should be getting speeds of around 17-19Mb...
 
Swifty55: G.992.3 is ADSL2.

Kristoph,
Kind of peculiar that you got just a single 'Assured Rate' profile result from the BT speed tester. I was expecting to see two, for 'Best Effort' and 'Assured Rate'.

Anyway, with the Assured Rate still at 2000 kbps I am still thinking that there is a stuck profile. Something to do with BTVision VoD.

Can you please post modem stats and a speed test result later on this morning.
 
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