Faulty micro filter caused Sync speed to drop

[#1]

It seems that a faulty micro filter was responsible for the drop in my Sync speed and subsequent download speed from 730 to 160 kbps yesterday (BT now shows my sync profile at 1500).
Having now replaced the filter, my router's sync speed is back to normal at over 7000, as well as all the errors back at zero.

FAULTY FILTER
<a href="http://www.divshare.com/download/8302625-5f1"><img src="http://www.divshare.com/img/8302625-5f1.jpg" border="0" /></a>
NEW FILTER
<a href="http://www.divshare.com/download/8303370-02f"><img src="http://www.divshare.com/img/8303370-02f.png" border="0" /></a>

I know I have to wait for the BRAS profile to catch up in order for my line speed to come back, but could someone check that my line is now running fine?
Thanks

[#2]

After checking the router this morning, I've noticed there are now 5 CRC Errors showing, as well as 1 Errored Seconds. My Sync rate is still at a constant 7072, which is a bit lower than the figure it was before. Is this something I should be worried about? Should there be no errors occurring and will this affect my profile returning to normal? Can someone please set my mind at rest about this?
Thanks

[#3]

I think I first posted this in the wrong section... sorry.
Anyway,
A faulty micro filter was responsible for the drop in my Sync speed on Wednesday (BT now shows my sync profile at 1500).  Having replaced the filter, my sync speed went back to 7072 and the errors to zero. After checking the router this morning, I've noticed there are now 5 CRC Errors showing, as well as 1 Errored Seconds (whatever they mean). My Sync rate remains at a constant 7072, which although stable, is still a bit lower than what it was before.
Is this something I should be worried about?
Should there be no errors occurring and will this affect my profile returning to normal?
Does it indicate the filter is not as good as it could be? I have a couple of new ones on there way just in case.
If someone could set my mind at rest about this I'd really appreciate it.
thanks

[#4]

[Moderator's post by Jim (Oldjim) Topics merged ]
The errors are nothing to worry about.
The dodgy filter will have caused the default noise margin to be increases and possibly interleaving turned on.
The default noise margin should fix itself but it could take a few weeks.
The interleaving is really only a concern if you are into on-line gaming

[#5]

Thanks for that Old Jim.
Just a couple more things if I may.
What effect will the increased default noise margin have on my speed?
Do you know why it could take a few weeks to fix itself?
Will my line speed return to normal automatically or do I need to raise a ticket once the 3 days have gone by?
Thanks

[#6]

It will reduce it slightly although given your attenuation I would have expected full speed of 7616 kbps even with the higher noise margin which tends to indicate a noisy line.
Having interleaved turned off will increase the maximum permitted speed to rise to 8128 kbps.
The three day period refers to the IPProfile and only running the BT Speedtest http://speedtester.bt.com/ will tell you that
Changing the default noise margin takes weeks not days and is automatic but you aren't likely to see any effect in real terms of the increase in speed.
One thing you could and should do is to plug the router into the test socket without any phones connected and report the result.

[#7]

BT results from the router plugged into test socket:
7008 downstream
448 up
IP Profile 1500
IP throughput 1269
The downstream figure seems rather low - could this have anything to do with the filter I'm using (it was borrowed from a friend while I wait for a new one to come)? I know that some are better than others.

How do I go about ensuring that interleaved is turned off?

[#8]

Hiya,
You can raise a ticket about interleaving or ask me nicely
The throughput is low atm because of the low IP profile.
The BT system will take some time to realise that you don't have a dodgy filter anymore, meaning the SNR will then drop and the sync speed should rise, but as Jim says, it can take a few weeks.

[#9]

James, can I ask you nicely to turn interleaving off on my connection?   It was turned off before but for some unknown reason it switched itself back on.

[#10]

Hey James
Would you be so kind as to turn off interleaving for me please? 
Just to clarify, when you say it will take the system some time to realise the dodgy filter is gone, the SNR will drop and the sync speed should rise, you're not talking about the 3 days it takes for my line speed to come back to my router's current sync speed are you?
Also, regarding how long this can all take, does it make a difference that I'm not with BT anymore as my phone line comes from PN as well?

[#11]

James, I was just wondering when my interleaving will get turned off?

[#12]

Quote from: esseff

Just to clarify, when you say it will take the system some time to realise the dodgy filter is gone, the SNR will drop and the sync speed should rise, you're not talking about the 3 days it takes for my line speed to come back to my router's current sync speed are you?

I expect James is not working today
You are correct that the target SNR margin is not directly related to your IP profile.  The IP profile normally takes up to 5 days to recover after sync speed has risen (although it can take longer IME).  I'm not sure about target SNR margin.  Mine has been at 15dB since I started monitoring it back in April.  If BT do lower your SNR margin then you'll only notice it when you resync and you should get a faster sync speed.  You'll have to wait a few days again for your IP profile to catch up.

[#13]

Thanks for that mapletree.
So it could take up to 5 days or longer to recover my download speed? Why does it need so long? Surely just having a period of stability is all that should be needed to confirm that the line is capable of a faster profile again. After all, the drop is not changed manually, it just happens automatically when the system notices the fault. Once that fault has gone I don't see why it can't just go back really quickly.

[#14]

esseff, I agree.  I don't know why BT take so long to increase the IP profile when they can decrease it rapidly.  It makes no sense.
Note that normally the IP profile does not take 5 days to recover.  IME it is usually 24-48 hours.  It takes longer if you don't leave your router on 24/7.  The PN profile can take 12 hours to catch up with the BT one.

[#15]

Well, it's been over 48 hours for me, and I'm still at 1500. My sync speed has even gone up a little more to 7264. I've just done another BT speedtest but my download speed is still at 1315. My router is left on 24/7.