ADSL Modems

[MadsDad]

Slightly odd question but does anyone know if you can connect multiple ADSL modems to the same phone line?

Someone I know has a problem where he can't receive the data from one end of his house to the other (very thick walls) but he has BT sockets at each end of the house so could he plug a different modem into each so he would pick up whichever modem was available according to where he was in the house?

[M.Mouse]

No you can't.

In very simple terms the ADSL Modem senses the broadband signal and then communicates with the Internet Service Provider's servers with log in name and password amongst other things.

The way it all works means that only one ADSL Modem on the line will work. In the early days of broadband and before I knew a little bit more about it I actually tried what you are asking!

It is possible to use repeater station(s) to solve the problem but I have never done so. I have used units like 'Homeplugs' which utilise the house wiring to transmit ethernet signals but they do not, I believe, comply with radio spectrum interference legislation. See here. (PLT: PowerLine Telecoms Networking is a technology that can be used for computer networking. It is also proven by EMC experts to be extremely harmful to the radio spectrum by causing very severe radio interference. PowerLine Networking is being widely promoted by telecoms and computer companies - despite NOT complying with accepted technical standards known as Electromagnetic Compatibility (EMC).)

[MadsDad]

Thanks, thats about what I thought but that was my guess. Because the modems regularly talk to the ISP (as well as receiving from) the signals would conflict and even if they didn't you can't log on multiple times probably.

Thanks.

[mixture]

MadsDad,

What you want to do is not possible, as outlined by M. Mouse.

The technically correct longterm solution to your problem is structured cabling. Not as expensive or complicated to install as you may think as long as you adhere to some basic rules on installation practices.

[MadsDad]

Yes, thanks mixture. No logical problem with installing the cabling, just that in the building it is in it will be a physical problem - think 2-3 ft thick walls to start with. (Just thought - not sure about planning/listed building stuff for the hole drilling/floorboard lifting etc.).

Might recommend getting a second phone line for the other end of the house.

[M.Mouse]

Might recommend getting a second phone line for the other end of the house.

But a telephone engineer will have to run a cable from where the telephone service cable meets the property to wherever the outlet is needed. It would also mean two line rentals and two broadband contracts!

As mixture suggests fixed cabling is the way to go. I have a couple of fixed cabling connections to my router. The advantages are speed, security and robustness of the connection without any effort or user configuration. Wireless is invaluable but can at times be a PIA for those reasons!

[Milo Minderbinder]

if the rooms are all on the same electricity distribution board, just use some "ethernet over powerline" adaptors
The network signal is simply carried through the mains

[M.Mouse]

if the rooms are all on the same electricity distribution board, just use some "ethernet over powerline" adaptors
The network signal is simply carried through the mains

Quite an echo in here.

[Milo Minderbinder]

sorry Mr Mouse, overlooked your squeak. Yes you got there first.
Interesting point about the interference legislation - the powers that be appear to prefer to turn a blind eye

[green granite]

the powers that be appear to prefer to turn a blind eye

But hopefully not for long, there's a court case pending over them and other illegal kit.

Re the wiring the connection, run it round the outside of the house and take it out and back in through the window frames.

[MadsDad]

But a telephone engineer will have to run a cable from where the telephone service cable meets the property.......

The operative bit of the sentence here is 'telephone engineer' and not 'you' (i.e. me). I didn't make it clear that the person concerned has multiple lines, on the same feed, so it would be to split the feed. Will cost for the installation I suppose but they are already paying multiple lines.

[Cremeegg]

Thick walls shouldn't be a problem to any competent installation person. I've a number of 1m long drill bits which when used with a decent SDS drill will get through every wall I've ever tried. I've also got some extension sections for walls over 1m. Whilst the likes of Screwfix will do you some drills I'd steer more towards specialist electrical wholesalers who will provide drill bits that will last more than 30 seconds.

[mixture]

I didn't make it clear that the person concerned has multiple lines, on the same feed, so it would be to split the feed.

Ooh err... do I hear the word DACS here ?

DACS+ADSL tend not to mix.

Hopefully your reference to multiple lines is just multiple pairs.

[MadsDad]

Mixture, they have multiple phone numbers (and bills thereof), haven't looked at the incoming set-up.

And Cremegg the phrase 'Competent Installation Person' is why I would recommend someone else do the job rather than me.

[Loose rivets]

When I was struggling to get a signal through 4 damp redbrick walls, I finally used a USB device which had a flip up lid that you aimed here or there.

I also downloaded inSSIDer 2.0 (free) and with this I could swing the aerial to the best advantage. Small changes made a huge difference, not only in the signal, but in the ratio of strength against neighboring users.



A pal of mine uses one of the mains-born gizmos in a huge old house. Perfect.