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ADSLMax & a thunder storm

daveyb
Grafter
Posts: 128
Registered: 04-08-2007

ADSLMax & a thunder storm

Do you think ADSLMax encountered a thunder storm during it's trial phase so that BT know how the DLM will respond?

My router has kindly emailed me to let me know it lost sync just before 5pm this evening and kindly emailed me the following sync speed stats between 16:45 and 17:02;

- 2336Kbps
- 2144Kbps
- 0Kbps
- 1152Kbps
- 2176Kbps
- 1792Kbps

so presumably my bRAS profile will be downgraded for 3 days.....oh well. But I'm sure BT will have thought this through :lol:

Noise graph's suddenly gone quite spikey too!



Thanks, David
31 REPLIES
Plusnet Staff
Plusnet Staff
Posts: 12,169
Thanks: 18
Fixes: 1
Registered: 04-04-2007

ADSLMax & a thunder storm

Hi,

That's a very good point and one I hadn't thought about before. In the past 6 or so years I've been working for a broadband ISP's the number of faults and problems I've seen caused by thunderstorms is huge.

I don't know if BT have tested Max during thunderstorms or not, I would hope so, but they might not have been able to on a huge scale.

We're currently creating some extra portal content for Max, I'll see if I can squeeze in a bit about storms.
octafish
Grafter
Posts: 124
Registered: 24-05-2007

ADSLMax & a thunder storm

Quote
the number of faults and problems I've seen caused by thunderstorms is huge.


Ah, yes.

I lost my adsl immediately after the thunderstorm earlier in the week. I had everything sitting behind a surge protector except....... the phone line into the adsl modem. Goodbye modem, as it turned out.

A salutary tale but one worth telling. And I never ever make this kind of mistake........

Steve
N/A

ADSLMax & a thunder storm

I've never heard of a surge protector for a phone line.

I do know that in South Africa, where they get really bad storms, everyone used to disconnect everything as soon as possible if a thunderstorm was on it's way, and still they get fried modems, processors and motherboards in spite of surge protectors, plus other problems.
I know that 3G phone is now the most popular way to connect in South Africa. Apparently 3G is not as likely to be fried by lighting.

How can I protect my modem apart from pulling the line from the wall?
BTW a few years ago at work lighting knocked out the surge protector, UPS, power supply, and modem. The only sure way seems to be to disconnect everything.

No storms yet south of London. Looking at the weather forecasts it looks as though even the rain will go around where I live.. not a drop for plants to drink. Sad
Community Veteran
Posts: 38,216
Thanks: 913
Fixes: 54
Registered: 15-06-2007

ADSLMax & a thunder storm

Belkin do surge protectors which also include telephone/modem protection and they are not much more expensive than the standard ones.
However apparently they can affect the snr which is not too good for MaxDSL
daveyb
Grafter
Posts: 128
Registered: 04-08-2007

ADSLMax & a thunder storm

hummm....... well it's gone past 8pm and the portal's still showing the stable rate as 1500Kbps so I guess a delta report didn't come through. Guess I'll need to keep my fingers crossed :roll:
N/A

ADSLMax & a thunder storm

We had a huge storm down here earlier on and a power cut for about 2 hours. When the power came back up I gained about 0.5mbps synch speed!

Thunder storms are great.
octafish
Grafter
Posts: 124
Registered: 24-05-2007

ADSLMax & a thunder storm

Quote
Belkin do surge protectors which also include telephone/modem protection and they are not much more expensive than the standard ones.



.... and guess who had one of these but failed to route the phone cable through it.....

S
Community Veteran
Posts: 6,111
Thanks: 1
Registered: 05-04-2007

ADSLMax & a thunder storm

For what it's worth during the storms in North London earlier this afternoon, my router also disconnected, and synced at a speed lower than I've ever seen it while on MaxDSL (which was also a little under the portal's reported stable rate). I've disconnected again since then though (not deliberately), and my sync rate is back where it should be... so it appears the BT system can overlook temporary downward spikes in sync speed.

Thomas
tangey
Grafter
Posts: 143
Registered: 29-08-2007

ADSLMax & a thunder storm

Your router will aways sync at the best speed that it can, so after the storm has past it'll sync back to where it was before the storm.

What BT's systems have done to your configuration due to dodgy connections during the storm is another thing altogether. If they've detected a couple of below par connections, they throttle back your connection for a while.

What I can't understand is why there is a need for this BRAS control at all. Surely all non-permanent connections have variation in capacity. For example if errors occur, packets have to be re-transmitted and thus thruput is reduced. How come when we were on 1Mbit or 2Mbit connections, and downloading from a site that could in theory provide 4M or 8M a sec or whatever, the connection didn't fall over...it could gracefully handle a big pipe into a wee pipe. Or indeed in the modem world, when you switched from a 33.6K/bits modem to a 56K modem, your ISP immediately gave you more data, it didn't take 3 days for it for the increased bandwidth to be reflected in your download rate.

When the BT ADSL systems detect a glitch, then apparently the specs say it'll take up to 75 minutes for BT adjust the maximum thruput to your connection. But what happens in those first 75 minutes. Assuming there is a genuine problem, until the rate is reduced, BTs systems are trying to send you move data than your side can take....but the world doesn't come to an end because of it, so clearly BTs systems can handle connections that can not take the full stream of data that has been assigned to it. So why the need for the BRAS adjustment, is it primarily a tool to save BT bandwidth further up the chain ?


The fact that ADSLmax (or is it just BTs implementation of it ?) cannot dynamically change the thruput based on the current connection speed appears to be the root cause of 90% plus of the issues being raised on plusnet, and I assume on all other ISPs.
daveyb
Grafter
Posts: 128
Registered: 04-08-2007

ADSLMax & a thunder storm

Quote
Your router will aways sync at the best speed that it can, so after the storm has past it'll sync back to where it was before the storm.


Not exactly - or rather it depends on what you mean. Unfortunately there's no event to trigger a resync once the line quitens down. So until I physically disconnect or reboot my router my line now sits happily at it's low 1792Kbps sync but with a very healthy noise margin (well, healthy for ADSLMax anyway). It's doesn't automatically resync to the higher speed unless something happens that makes sync drop and then, as you quite rightly say, it will resync at it's "normal" speed.

Quote

What I can't understand is why there is a need for this BRAS control at all.


I'm with you here. Equally, I don't understand why the bRAS profile isn't adjusted both ways with 75 minutes. Why have BT stipulated that it needs 3 days for an increase. In my own experience, there are far more temporary drops in sync speed than there are artificially high syncs - infact, I've had several drops that are corrected as soon as I reconnect but I've never had an unusually high one. All things being equal my sync speed is pretty stable and stays connected at it's "natural speed" for a week or more before hitting another temporary glitch.
tangey
Grafter
Posts: 143
Registered: 29-08-2007

ADSLMax & a thunder storm

What I should have said (and what I meant) "was that your router will always sync at the best speed it can so after the storm it'll sync back to where it was before, on its next sync."
N/A

ADSLMax & a thunder storm

Quote
Quote
Belkin do surge protectors which also include telephone/modem protection and they are not much more expensive than the standard ones.



.... and guess who had one of these but failed to route the phone cable through it.....

S


I have one and ADSL doesn't work when connected through it Sad
octafish
Grafter
Posts: 124
Registered: 24-05-2007

ADSLMax & a thunder storm

Quote
I have one and ADSL doesn't work when connected through it


Hmm, my reluctance to use it was down to suspecting it might introduce more noise onto the line. Maybe losing a modem every 2 years isn't so bad! I get a more or less steady 5.5Mbps at the moment
N/A

Grr

Mine line still has loads of static and its dropped my snr downto 7db from 10db which is a pain as at night it can drop a cpl more..

BT wont fix until the 8th .. 4 days lead time how pants is that..