Strange DSL Behaviour

Status
This thread has been Locked and is not open to further replies. Please start a New Thread if you're having a similar issue. View our Welcome Guide to learn how to use this site.

dranjam

Thread Starter
Joined
Jan 27, 2007
Messages
4
Hello.

I am using UK's BT Broadband, and it wasnt' working very well till last days, but it was ok, now it changed into a nightmare.

1. My router stats:
Code:
	Showtime Firmware Version:	3.24
	Line State:	SHOWTIME
	Modulation:	G.dmt
	Annex Mode:	ANNEX_A
	Startup Attempts:	1
	Max Tx Power:	-38 dBm/Hz
	CO Vendor:	TEXAS_INSTRUMENTS
	Elaspsed Time:	0 days 2 hours 16 minutes 7 seconds

Downstream Upstream
	
SNR Margin	11.3	21.0	dB
Line Attenuation	60.5	31.5	dB
Errored Seconds	2603	68	<----- What's this?
Loss of Signal	0	0	
Loss of Frame	0	0	
CRC Errors	5282	68	  <---- What's this?
Data Rate	576	288	kbps
Latency	FAST	FAST
I had this kind of stats for months, but it wasn't working very bad, it was dropping connection couple of times a day, it was annoying but I could live with it. Up to a certain limit.... What might be the reason for this? I have conexant router and I've heard it's not very good, should I change it?

2. It all went worse yesterday
I didn't change any settings, didn't install any new hardware or soft, but now transfer rate is at 5kb/s. I checked for viruses with Avast (result: PC was clean), I checked for rootkits with BlackLight (result: PC was clean) I am also checking it with Windows Defender atm (nothing so far). I use Windows Firewall. Pings are slow, 1000ms to most popular sites on average.

After I turn the router off for 30 seconds and turn it back on, connection is good for 1-3 minutes, then it goes slow again. It also goes fast again (for 20-30 minutes) every now and then without any action from my side. I have 2 PCs in my network, 1 wireless and 1 ethernet, both have this problem.

Writing fast connection I mean 400-450 kbps, by slow connection I mean 20-30 kbps.

Okz, I hope the info I am giving is enough to make a clear view, let me know and I will provide further details.
Thanks in advance :).

EDIT: BT online tools cannot check my line, gentelmen from the helpdesk said the line is ok (but I don't trust him too much :p).
 

MMJ

Guest
Joined
Oct 15, 2006
Messages
3,625
What is the speed you signed up to?

Did you contact you isp?

Did you try the internet on another computer?

Good trouble shooting, btw. ;)
 

1002richards

Retired Trusted Advisor
Joined
Jan 29, 2006
Messages
5,333
Hi,
We had poor connection with BT b/band. Called out the engineer ( no charge) he made some changes at a "junction box" a few yards up the road from my house and all now works fine!
(Of course it will all go t*ts up now I've said that!!!)

Good luck
Richard
 
Joined
Aug 26, 2005
Messages
894
Downstream Upstream

Errored Seconds 2603 68 <----- What's this?

CRC Errors 5282 68 <---- What's this?


Errored Seconds is exactly that, since the router last had it's stats reset (or power cycled) the router has seen 2603 errored seconds FROM the DSLAM. An errored second is a value that counts how long the SNR is too high for the xDSL interface to actually decode a modulated signal.

CRC errors are a bit higher layer, these are frames received that didn't pass layer 2 header cyclic redundancy checks. So, the xDSL could decode the modulated signal, but the frame it decoded didn't make sense as a packet.

To sum it up, your modem has poor signal to noise (11db) downstream from the DSLAM to your modem. It's low enough that your modem can't decode frames (summing up to 45 minutes of outage). This translates into extremely poor performance.
 

TerryNet

Terry
Moderator
Joined
Mar 23, 2005
Messages
81,424
So, what do you do about 01111110's last paragraph? First, thank him!

Second, check all your connections and wires that you can from your modem back to outside. I'd remove any jacks I can reach and reconnect them. Make sure you have only one splitter in the DSL line. Make sure you have filters on all phones, answering machines, faxes, etc.

Third, ask (nicely at first) your ISP to check their lines and give them the signal to noise data.
 

dranjam

Thread Starter
Joined
Jan 27, 2007
Messages
4
Thank you everyone, this is a lot more than I expected :).
Maybe my english is not good enough to comprehend 01111110's post - is it my routers fault or DSLAM is just too far (which is possible, as I live on outskirts of town) ?
I will try contacting ISP again, but when I tried this before the gentelman on the line seemed to know even less than myself about errored seconds... Maybe it just takes some luck :>.

Hmmz, I just recalled. Is there any logical explanation in drop in connection speeds from ~450 kbps, as it used to be 2 days ago, to ~100 kbps as it is now? Maybe just maintanance work at exchange point or ... ?
 

TerryNet

Terry
Moderator
Joined
Mar 23, 2005
Messages
81,424
Distance is a DSL problem, but unless you moved farther away in the last couple days it doesn't explain the 450 -> 100 drop. :)

If 450 kbps is a lot less than you are supposed to be getting, then distance is a possible problem. As far as what has caused the drop, it could be the modem failing but is more likely a cable/wire, connection or filter failing.

In addition to my previous suggestions, disconnect all phones, etc., and see if there is any difference. If your 450 Kbps comes back, then start adding phones back one at a time until you find the filter that failed.

After you've eliminated your own wiring and equipment as possible problems, just tell your ISP how your speed has dropped, you've been advised by an expert that the signal to noise ratio is bad, and please check the line and their modem.

I think that a sudden change like you experienced is often because of an overhead wire becoming loose or a buried cable getting wet or chewed.
 

TerryNet

Terry
Moderator
Joined
Mar 23, 2005
Messages
81,424
Forgot that you had a router. Obviously the first thing to check is what happens when you connect a computer directly to the modem.
 
Status
This thread has been Locked and is not open to further replies. Please start a New Thread if you're having a similar issue. View our Welcome Guide to learn how to use this site.

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

As Seen On
As Seen On...

Welcome to Tech Support Guy!

Are you looking for the solution to your computer problem? Join our site today to ask your question. This site is completely free -- paid for by advertisers and donations.

If you're not already familiar with forums, watch our Welcome Guide to get started.

Join over 807,865 other people just like you!

Latest posts

Staff online

Members online

Top