Surge protection for ADSL

[armadillo]

I have been good, read the FAQs and searched and read every entry on surge protectors in the forums. You guys and gals seem friendly so I'll ask my question.

Has anyone found a method of surge protecting the phone line, or adsl connection into the router, without increasing the noise or decreasing the sync speed?

Stats and details of what I have tried follow.

I am using a Netgear DG834 (wired) router.
Router power plugged into a Belkin surge protector that I bought today (claims 2190 joules surge protection).
ADSL to router not at present surge protected. Microfilter straight into BT master socket and router connected to that microfilter.
PC on other side of bungalow and powered by a very nice APC surge protected UPS (runs the PC and monitor for about 90mins if power fails!).
LAN cable, 15metres, connects router to PC.

With that setup, I get good connection stats on my ADSL max.
Downstream attenuation 32dB
Sync 7616 Kbps
Noise margin 9.3dB right now (at about 0130 hours)
Throughput usually around 6.0 to 6.5 Mbps.

The Belkin surge protector has telecomms protection available. If I connect that to the BT master socket and connect the microfilter to the surge protected output, I re-sync a good bit slower, at about 6000 Kbps with 9dB noise margin.

I also have a little APC telecomms surge protector that I used to use when I connected via a modem. So I tried the APC telecomms protector for the router instead of the Belkin protection. That also lowered my sync to about 6000 Kbps.

So it seems that either of the two telecomms surge protection devices that I have tried cause a drop in sync speed of about 1600Kbps. That is a significant sacrifice in sync speed.

I do not want to do any more disconnections and reconnections now for a few days. And next time I do an experiment, I'll do it mid morning when the noise will be lower and I may get the high sync rate even with the additional noise that either telecomms surge protector is introducing.

When in Maplins today, I saw a surge protected ADSL microfilter. I might get one and try it.

Anyone have any methods that work well?

[Simon]

You don't need to worry about asking questions here.  We're not one of those forums that tell people to "Use the Search button!"

Now, I'll leave it to someone who knows, to answer your question. 

[Rik]

Personally, I've never found an anti-surge that didn't have an impact on performance, so I prefer to connect directly. The only times I disconnect the router are when I'm going to be away, or there is thunder around. In both cases, power down from the mains before unplugging from the phone line - it shouldn't then affect your profile.

[tehidyman]

Personally, I've never found an anti-surge that didn't have an impact on performance, so I prefer to connect directly. The only times I disconnect the router are when I'm going to be away, or there is thunder around. In both cases, power down from the mains before unplugging from the phone line - it shouldn't then affect your profile.

Having recently installed ( on your advice) an APC surge protector and battery backup just for the UPS component would you advise that the Fax/modem/phone RJ11 connections are not used and also what is the nature/extent of the impact on performance.

[Rik]

I certainly don't bother to use the phone line filtering - keeping the mains clean is much more important to me. On those filters that I've tested, I've usually seen a small rise in attenuation and, therefore, a small drop in sync speed. If you're near a profile threshold, that can be critical. IAC, I'm not convinced enough by these devices to trust them over a complete disconnection, which I know is safe.

[Polchraine]

The surge protector also acts as a "filter" - not designed to but the nature of the components fitted will make it so.

With your Netgear are you able to get a Bitloading plot that shows the number of bits used in each bin?    If so, a with and without would be useful and I could see what the filtering effect is.


The other thought is that some Belkin power distribution boards have an ADSL splitter incorporated.    If yours has, are you taking the unfiltered ADSL output? 

[armadillo]

Personally, I've never found an anti-surge that didn't have an impact on performance, so I prefer to connect directly. The only times I disconnect the router are when I'm going to be away, or there is thunder around. In both cases, power down from the mains before unplugging from the phone line - it shouldn't then affect your profile.

Thanks Rik. That suggests I can stop trying to find a no-impact surge protector. The advice to power down before disconnecting the phone line is great, thank you. I had seen that in the brilliant FAQ and duly noted it (though not until I had done a couple of disconnects without powering down). I too am connecting directly at the moment though I am a little uneasy about doing so.

[Rik]

I've never had a problem. The only two issues you need consider are a power cut or BT engineering work while you're away, which can mess with your profile, or a lightning strike at your end or the exchange. If the ground potential between the two locations is large, you'll get a surge which can wipe out any connected equipment. I've yet to see one, though I do take care. You can follow storm locations/movement here:

http://www.isleofwightweather.co.uk/live_storm_data.htm

[armadillo]

I certainly don't bother to use the phone line filtering - keeping the mains clean is much more important to me. On those filters that I've tested, I've usually seen a small rise in attenuation and, therefore, a small drop in sync speed.

Yes, I forgot to mention that it took my attenuation from 32dB to 33dB. Though I guessed that the 1600kb/s drop in sync speed was caused by a constraint to preserve target noise margin rather than directly because of the increase in attenuation. But I know nothing. I'll be asking a separate question about some of the dependencies in the figures.

As for not relying on surge protection in a thunderstorm, I agree. But I would rather have some protection than none at all when I am out, though not away. Thunder is not always forecast.

I am not really worried about frying the router as it is easily replaced. What I am worried about is frying the PC motherboard with a surge transmitted from the phone connection through the router and down the LAN cable. It makes me wonder if I should go wireless but that has its own drawbacks and idnet tech support recommended wired before I migrated here.

[pctech]

I have mine connected directly too but the Ethernet cable from the router is filtered before reaching the PC.

[Rik]

What do you use, Mitch?

[Rik]

Yes, I forgot to mention that it took my attenuation from 32dB to 33dB. Though I guessed that the 1600kb/s drop in sync speed was caused by a constraint to preserve target noise margin rather than directly because of the increase in attenuation. But I know nothing. I'll be asking a separate question about some of the dependencies in the figures.

Fire away.

As for not relying on surge protection in a thunderstorm, I agree. But I would rather have some protection than none at all when I am out, though not away. Thunder is not always forecast.

True, and I do have the luxury of being here and online most of the day. However, to put it in perspective, I've had ADSL since it became available, and I've used dialup before that, from 1984 onwards. I've never fried a router or modem yet.

I am not really worried about frying the router as it is easily replaced. What I am worried about is frying the PC motherboard with a surge transmitted from the phone connection through the router and down the LAN cable. It makes me wonder if I should go wireless but that has its own drawbacks and idnet tech support recommended wired before I migrated here.

See Mitch's post.

[armadillo]

The surge protector also acts as a "filter" - not designed to but the nature of the components fitted will make it so.

That makes sense. It has to put something between the input and the surge protected output.

With your Netgear are you able to get a Bitloading plot that shows the number of bits used in each bin?

I don't think so, not that I know what bitloading is 
All I can get are TxPkts    RxPkts    Collisions    Tx B/s    Rx B/s    Up Time

as well as attenuation, margin and sync.

The other thought is that some Belkin power distribution boards have an ADSL splitter incorporated.    If yours has, are you taking the unfiltered ADSL output? 

This one only has unfiltered output sockets. They are standard telephone sockets and I therefore put a microfilter between there and the router's input cable.

[Rik]

Netgear's don't give bitloading, at least I've never been able to find it.

[armadillo]

You don't need to worry about asking questions here.  We're not one of those forums that tell people to "Use the Search button!"

Thanks Simon. I am glad about that. Some forums seem set up to terrify newcomers!

[Tacitus]

I've used one of these from Clarity in the past.  I can't say I noticed any significant effect on the attn or anything else.  Whether it is any use against lightning surges is another matter.

They are currently listed as being out of stock but no doubt they could get one for you.

[Simon]

Thanks Simon. I am glad about that. Some forums seem set up to terrify newcomers!

Oh, we lead you into a false sense of security first.   

[armadillo]

I've never had a problem. The only two issues you need consider are a power cut or BT engineering work while you're away, which can mess with your profile

I am confused. I thought you said that powering off the router stops the profile being affected.

or a lightning strike at your end or the exchange. If the ground potential between the two locations is large, you'll get a surge which can wipe out any connected equipment. I've yet to see one, though I do take care.

Same here. Fortunately, my bungalow has higher buildings and trees around and so has the exchange. I have lived here for 25 years and neither I nor any of my neighbours has ever had a lightning surge. My sister, in France, had a catastrophic one that killed her PC, phone, freezer and cooker.

You can follow storm locations/movement here:

http://www.isleofwightweather.co.uk/live_storm_data.htm

Good grief, that is some site!

[Polchraine]

A bit loading graph from a 2700.    Simplistically,  the ADSL signal is split into lots of separate carrier frequencies and each of those can accommodate a number of data bits - some can take none and interference/noise shows up as low numbers.

There is a free application that allows you to capture it on Netgear routers (but I cannot remember the name).

[Rik]

Oh, we lead you into a false sense of security first.  

[Simon]

I am confused. I thought you said that powering off the router stops the profile being affected.

If you power off 'gently', ie, at the power socket, the router will send a last 'dying gasp' to tell the exchange that all is OK.  In the event of a sudden power failure, as with a power cut, it won't.

[Rik]

I am confused. I thought you said that powering off the router stops the profile being affected.

It does, but if you get a power cut, then a surge or several switching blips when it comes back up, they can cause trouble, hence the UPS.

Same here. Fortunately, my bungalow has higher buildings and trees around and so has the exchange. I have lived here for 25 years and neither I nor any of my neighbours has ever had a lightning surge. My sister, in France, had a catastrophic one that killed her PC, phone, freezer and cooker.

A friend of ours had their chimney stack blown off the house, just as if someone had bombed it. It was a real mess.

Good grief, that is some site!

Handy to keep an eye on.

[armadillo]

Thanks Tacitus. That does look well worth trying out. From the description and the picture, that does not show what the female end looks like, I guess you plug the device between the microfilter's adsl out and the router cable. Yes? So the connection would go: BT master socket, to microfilter, to surge protector, to router?

[Steve]

There is a free application that allows you to capture it on Netgear routers (but I cannot remember the name).

DMT shows a small graph of the bit loads for compatible routers

http://dmt.mhilfe.de/

[armadillo]

Oh, we lead you into a false sense of security first.   

I am quaking with fear over the imminent punishment.