With broadband, what happens if you switch the modem off?

[packman 0]

Hi, I'm in the process of going broadband, ADSL to be precise. I'll be using an external-type multi-port router-modem.

 

Once the ADSL signal is established and I'm up and running, what will happen thereafter if I power off the router-modem, or physically disconnect the line cable? Anything undesirable? Will it re-synchronise properly when I re-connect or lose any data such as IP addresses?

 

I don't anticipate turning off the router-modem that often but I would certainly turn off the PC on a regular basis. Would anything undesirable happen to the router-modem as a consequence of that?

 

My understanding is that, for those people who choose to have a dynamic IP address for the router-modem, turning off the PC or the router-modem would cause the current IP to be lost and a new one issued by the ISP's server, once the router-modem/PC were powered on again. The ISP would, in any event, periodically issue a new IP address.

 

What would happen if you were using a static IP address for the router-modem, instead (bearing in mind that many ISPs will tell you to set the router up as if getting an IP address automatically but their server in practice issuing the same IP address each time)? Would then powering off the PC, or the router-modem itself, produce any undesirable consequences?

[theefool 0]

Yes, you can freely turn off the dsl modem. You just lose connection to the internet. Turning it back on, will re-establish that connection.

[packman 0]

Presumably, if I turn off the PC (only the PC), the Internet connection will remain? Or will it?

[ScinteX 0]

Hiiii

Yep it will remian. The easiest way to imagine this is like:

 

Your router is like a little PC that connects to the internet. Inside the router is your login and password for your ISP's ADSL network. When you turn on the router, it starts up and initialises it's DHCP (for networking), then goes on to login into the ADSL world.

 

When you turn your PC on, it goes off to your router and gets an IP address. You then tell your PC to use the router for internet access.

When you turn your PC off it just hands back the IP address to the router, then shutsdown. The router just sits there waiting for the next client to come along (be it your PC again or another PC/device).

 

BTW my router runs linux! It's only purpose in life is networking, firewall and loging onto ADSL.

 

 

[packman 0]

Thanks, Scintex (and theefool).

 

As a final query, have you any experience of how well the little plug-in ADSL microfilters work? What I'm getting at is do they truly enable a telephone to still be plugged into the line and used, or is there always some resultant diminution of audio quality on the phone? I ask because a friend on the other side of town recently moved across to ADSL broadband and she found that the microfilters she used (allegedly, good-quality ones) were all but useless; trying to use the Internet and the phone at the same time was impossible and she had to abandon the idea of using a plug-in phone, in the end.

Judging by what she's told me, she did understand the rules about using microfilters in the various phone outlets in the house.

 

[theefool 0]

Personnaly I think those little microfilters are useless. Back when I had adsl in 1999, living in Norfolk, VA, we didn't have those stupid little microfilter phone jack thingamajigs. The phone company made a change to my phonebox outside my apartment. That was it. Never had a problem. No audio problems or anything.

 

Now I live in Indiana, SBC uses those microfilters. I'm on cable now, so I don't have to worry about them.

 

Anyway, a friend of mine usually has 5 of those filter things at his house. He says he has them cause the filters can go bad.

 

Hmmm, probably didn't answer your question there. One note: ADSL back then was $100 a month from the phone company, I used this other fortune 500 company that was $75 a month 1500/768.

[ross_aveling 0]

I have 4 phone points in the house. I have placed a microfilter into each one (even though one isn't currently being used) and have never experienced a problem at all. I've never had a voice call breakup or crackle once. Plus my filters were also bought off eBay on the cheap - for a couple of quid each.

 

Perhaps I should count myself lucky and whilst I'm no comms expert, maybe the quality of the telephone cabling has to be pretty good to start with.

 

BTW - Your local telecom company may offer a service to install a master filter (at your home's junction box) to have the same setup to what theefool had. I know BT does it here in the UK.

[packman 0]

Ross,

 

BT themselves might offer that 'outside box' service, but an ISP-affiliated-to-BT would not. The user would have to pay for its installation, I suspect.

 

The purpose of each microfilter is two-fold, as I understand it. First-and-foremost, to buffer the speech signal from the ADSL signal and, second, to prevent spurious electrical noise (spikes and other disturbances) on the line from getting through to the phone. Presumably, more noise can ensue from an ADSL-enabled line than otherwise? It seems to me that the requirement will be particularly stringent where the user is situated a long way from the local exchange.

 

Note that the ADSL line itself does not require, nor should it have, filtering.

 

In MY case, I AM a long way from the exchange and it remains to be seen if both my modem and my telephone can be successfully used on the same line. I've organised the telephone wiring in the house to be as near-ideal as possible.

[ross_aveling 0]

Originally posted by packman:

Quote:

Ross,

 

BT themselves might offer that 'outside box' service, but an ISP-affiliated-to-BT would not. The user would have to pay for its installation, I suspect.

 

Yes you are quite correct. As I said, the local telecoms company [in this case BT] will offer this to you as a 'product' which you will of course have to pay for. Before the days of self-install ADSL this is what everyone would have had done regardless of ISP.

 

Quote:

The purpose of each microfilter is two-fold, as I understand it. First-and-foremost, to buffer the speech signal from the ADSL signal and, second, to prevent spurious electrical noise (spikes and other disturbances) on the line from getting through to the phone. Presumably, more noise can ensue from an ADSL-enabled line than otherwise? It seems to me that the requirement will be particularly stringent where the user is situated a long way from the local exchange.

 

Note that the ADSL line itself does not require, nor should it have, filtering.

 

So you're saying that you only need to use microfilters if you would like to make voice calls over the same line? Interesting, I've always thought (perhaps wrongly) that the data and voice 'channels' (right word??) operate at certain frequencies and the filters ensure that the different frequencies are kept entirely seperate, and thus don't interfere with each other.

 

Quote:

In MY case, I AM a long way from the exchange and it remains to be seen if both my modem and my telephone can be successfully used on the same line. I've organised the telephone wiring in the house to be as near-ideal as possible.

 

In MY case, I AM a fair distance from the exchange. You asked for experience with microfilters, I gave you mine. You can take it or leave it.

 

 

[packman 0]

Ross,

 

Apparently, you only need to use any microfilters if you have a phone, fax machine or other telecomms bit of kit plugged into any of the phone sockets in the house - and you plug in the filter at the socket where you use that bit of kit ONLY. So, just to make it clear, THAT'S what I'm saying. Thus, if you use a mobile-phone and don't bother with a standard plug-in phone, there should be no need to install any filters.

 

ADSL tones and telephone speech signals do, of course, operate at quite different frequencies but they can both appear on the line at the same time if you have a telephone plugged in. This, in itself, isn't problematical but what is problematical is components of the ADSL signal reaching any non-ADSL bit of kit that might be plugged in, such as the telephone. The latter would tend to get crackling noises coming through. The filter is there to block that kind of interference; the filter doesn't in any way modify the signals on the line itself, it merely blocks components of the ADSL signal from reaching the telephone.

 

I've heard of wide variations in effectiveness of these filters, though, and I suspect that some filters are better than others. Also, crackling noises on the line can often be there already (regardless of the line being ADSL'd), from general electrical noise being picked up on the line between the exchange and the house (from crosstalk between other pairs of wires, interference from power cables, etc). The further away you're situated from the exchange, the more likely you are to get noise on the line.

 

It seems that, in your case, your line is relatively clean and your filters work well.