Drop in speed help stablize line?

bloodline76 · 2 Oct 2008 at 19:56

I have been having trouble with my internet line for the past month. I was getting a steady 3.5mb and was happy enough with that.

I have been conatcting my provider and to fix the problem they have dropped my speed down to 2mb which seems stable but should that be the only way of fixing the issue?

As I was getting a constant speed of 3.5mb to 4.5mb before without problems until a month ago.

Is this just an easy way of dealing with the problem, or is that the only way?

Thanks!

mp260767 · 2 Oct 2008 at 22:52

check the stats on you're router line Attenuation, sn margin etc, i had the same problem, mine was too "noisy" and was dropping when i was gaming, although normal net stuff was ok.

bloodline76 · 3 Oct 2008 at 17:40

mp260767 said:
check the stats on you're router line Attenuation, sn margin etc, i had the same problem, mine was too "noisy" and was dropping when i was gaming, although normal net stuff was ok.

Where do I check that?

Its a siemens SE587

tolien · 3 Oct 2008 at 17:57

The web interface somewhere, probably under ADSL or connection details or something like that.

bloodline76 · 3 Oct 2008 at 18:34

Status: ON
US Trained Rate: 288 kbps
DS Trained Rate: 2294 kbps
Current US data rate during last 30 sec: 0 kbps
Current DS data rate during last 30 sec: 427441.561 kbps
Local Line Attenuation: 50.0 dB
Remote Line Attenuation: 24.0 dB
Local SNR Margin: 16.60 dB
Remote SNR Margin: 31.0 dB

Does that tell you anything?

-Aura- · 3 Oct 2008 at 22:37

Yes, your looploss (Local Line Attenuation) should be fine for a sync speed of between 3.5-4.5 Mbit, easy! You are enjoying a huge SNR margin (most routers are stable as low as 6dB which is the threshold that MaxDSL equipment at exchange resyncs should SNR drop) which your ISP knows will cover up any crappy service and give you stability, but in this case it has borked your sync.

Now, does your service decline at any particular time of the day? If it gets worse towards the evening, maybe your pipe is congested. Crosstalk comes into play more in the darker nights too.

I`ll bet pound to a penny that you are with one of the cheapy ISPs such as Talk Talk or Tiscali? You get what you pay for I`m afraid in with this type of ISP, they over-subscibe their pipes. My next door neighbour is with Tiscali, we even share the cable up to our house then it splits his way and mine. He syncs at 3Mbit, terribly too. I sync in between 5.8Mbit and 6.8Mbit with IDNet with pings ca 30, nuff said

tolien · 3 Oct 2008 at 22:48

Congestion won't affect SNR margin or stability, and neither will the ISP.

Usual drill, try with the modem connected to the master socket and no extensions.

-Aura- · 3 Oct 2008 at 23:03

Congestion won't affect SNR margin or stability

Agreed, but the op is talking about sync, not throughput, I was attempting to find out the possible reason why they would drop the ops sync.

and neither will the ISP

To an extent. If op is on LLU then the ISP is directly responsible for congestion. If ISP is renting from BTw then they may be over capacity their end and need to light some more pipes up. If it`s a BT exchange congestion problem, agreed that this affects all users irrespective of ISP.

You gave good advice regarding master socket, but the op had a good sync until recently. Personally, I use a filtered face plate and Cat5 wiring everywhere, ringwire removed etc etc, but I just keep recalling that the Ops problem is recent and it was fine beforehand.

bloodline76 · 3 Oct 2008 at 23:52

Yep I have tried all the normal things with equipment and master socket but get the same. I am lucky enough to have spare of everything including a router and swapped them all one by one but still the same.

It is with tiscali that im with but i have been with them for over four years without much problems until recently. Is there anything that I can tell them to do or try? Thanks for all your advice, very much appreciated!

-Aura- · 3 Oct 2008 at 23:59

It`s a bit of a Catch22 for you. They have dropped your line speed because you approached them about stability. IMO, they fobbed you off and will most likely turn around and say tough, as they acted and your stability problems went away.

Ask if they can sync you at say 3Mbit?

Ya know, their equipment should handle your sync automatically. You will have a line profile based on your SNR and sync accordingly anyway. :\

tolien · 4 Oct 2008 at 00:23

Sync rate will change regardless of IP profile - your throughput would settle towards some stable point, but your sync rate would continue to fluctuate with the accompanying instability.

A router that would work with DMT might be useful though, if you haven't already got one - you could tweak the target SNR margin yourself, until you reached the minimum point that left you with an acceptably stable connection (more disconnections or more speed, take your pick), with more granularity than Tiscali will give you, and without talking to Tiscali's friendly, high-quality technical support staff.

auraindigo said:
Agreed, but the op is talking about sync, not throughput, I was attempting to find out the possible reason why they would drop the ops sync.

The OP already said it was for stability, and I was talking about what you were implying - that Tiscali was responsible for your neighbour only synching at 3Mbps.

To an extent. If op is on LLU then the ISP is directly responsible for congestion. If ISP is renting from BTw then they may be over capacity their end and need to light some more pipes up. If it`s a BT exchange congestion problem, agreed that this affects all users irrespective of ISP.

Which has nothing to do with the sync rate though. Exchange congestion is virtually unknown these days (at least compared to on Centrals) and the OP's sync rate is 22kbps over the minimum for the 2Mbps IP profile, so the problem isn't congestion.

the op had a good sync until recently.

And then the ISP increased the target SNR margin to make up for the connection being unstable...

-Aura- · 4 Oct 2008 at 00:47

A router that would work with DMT might be useful though

Yes it would or a Netgear DG834(x) with a modded firmware (there may be others), I have a modded DG834N.

tolien, so why do you think his line has suffered a sudden setback then? I have my opinions, what`s yours?

Yes, I have mentioned sync rate frequently and am well aware of what it means to a line and what other factors determine sync etc etc etc, but ultimately I firmly believe that over-subscribed and especially LLU exchanges introduce some form of cap to throttle bandwidth, in this case and specifically, they have indeed raised target SNR which at the end of the day ensures that bandwidth by the op is cut by 50% or more.

tolien · 4 Oct 2008 at 09:10

auraindigo said:
tolien, so why do you think his line has suffered a sudden setback then? I have my opinions, what`s yours?

What? The OP phoned ISP, said "my connection is unstable", ISP increased target SNR margin, sync rate subsequently dropped. It's got nothing to do with throttling or oversubscription or anything else.
The real issue that needs to be dealt with is the instability that increasing the target SNR margin covered up.

You don't know if the OP's on Tiscali LLU or not, but BT Wholesale aren't tweaking target SNR margins to fix congestion...

edscdk · 4 Oct 2008 at 09:18

Don't know if these are available yet but might be worth a look if they are

hxxp://www.theinquirer.net/gb/inquirer/news/2008/10/02/bt-speeds-broadband-gadget