Q about adsl filters and jack points...

Q about adsl filters and jack pointsok, i have 3 jack points in the house, 2 downstairs and 1 upstairsi have a filter in with the phone and a filter with the computer and another filter with the computer upstairs, my prob is that only one modem will display the adsl/link act light at any one timeany ideas on why this is?? they will not all run at once even thou they are all in separate jack points and filters..

geek_bubble-bobble, Nov 26, 1:02 pm

Don't put filters on the computers if they are on broadband. Filters are just for phones, faxes, modems.

geek_r.g.nixon, Nov 26, 1:06 pm

Well the modems came with the filters.. i have to have them connected (im with xtra)

geek_bubble-bobble, Nov 26, 1:07 pm

And use only *one* ADSL router per phoneline. i.e. One ADSL router per house is usual.

geek_r.g.nixon, Nov 26, 1:08 pm

modems don't come with filters I guess by "modem" you mean ADSL ROUTER. Modem actually means the older slower dial-up devices that don't do broadband. If an ADSL Router box says "modem" on it, they are misusing the term.

geek_r.g.nixon, Nov 26, 1:11 pm

Telecom said i needed to plug one filter in for every jack point that is being used (i am using 3) is this not right?

geek_bubble-bobble, Nov 26, 1:11 pm

Oh lol thats what i meant.. adsl router.. *sorry*

geek_bubble-bobble, Nov 26, 1:13 pm

One filter for every phone, fax, dialup modem (which you probably will not be using if you have broadband)

geek_r.g.nixon, Nov 26, 1:13 pm

Yep i do have broadband everything works fine, but as soon as i connect the computer upsatirs it all turns to *shite* that too is broadband with an adsl routerwould it be easier to just have a wireless modem for the 2 computers??

geek_bubble-bobble, Nov 26, 1:15 pm

Yes, like I said only have *one* router to get your broadband. You need either wireless or an ethernet cable to connect to the computer upstairs.

geek_r.g.nixon, Nov 26, 1:21 pm

Ohhh make sense now, thanks for your help

geek_bubble-bobble, Nov 26, 1:22 pm

Right lets clear this up...the filters you have been supplied have two outlets on each one is labelled 'phone' and the other 'adsl' the adsl side of the filter does NOTHING. It's NOT any kind of filter on that side of the thing at all it's just a 'dumb connection' wired straight through. The 'phone' side of the filter filters OUT the broadband signal so that it doesn't interfere with phones ....you DONT need a filter on an adsl modem at all ! Ok 2nd point. From what I understand you have more than one adsl modem and you are expecting it to be possible to run more than one at a time on one phone line. Its NOT possible. you can ONLY run ONE adsl modem at a time on ONE phone line.

geek_drcspy, Nov 26, 1:24 pm

This is a noobism thread I just installed a splitter to isolate my alarms by looking it up on
the intraweb using GOGGLE,I have 3
Modem/Routers & a Linksys Wireless
access point.I only use 1 computer
now,should I install all Routers and
get a wireless card for the ones I'm not using? They'll be running well 1
day,even though they're not mine-But
they're in the house for repairs!???

geek_deodar, Nov 26, 1:30 pm

r.g.nixon, That's not correct. A modem - short for modulator/demodulator - is necessary for both dial-up and broadband connections. Both dial-up connections using base-band (audio) frequencies and broadband using RF utilize an analogue signal which has to be converted to a digital signal for the computer. When sending data from the computer the digital signal has to be converted to analog, to modulate the carrier frequency with that signal. Both these jobs are done by the modem.

A router is a digital device and cannot recognise either dial-up or broadband analogue data without a modem.

geek_cjdnzl, Nov 26, 4:53 pm


geek_lostdude, Nov 26, 4:59 pm

interesting I am doing some checkingnot that I doubt you. All I have found so far is this from http://en.wikipedia.org/wiki/Digital_Subscriber_Line "Modems actually modulate and demodulate a signal, where the DSL Transceiver is actually a radio signal transmit and receive unit."

geek_r.g.nixon, Nov 26, 5:08 pm

r.g.nixon Have a look at this Wikipedia page. it gives a better explanation, and talks about base-band and DSL modems: http://en.wikipedia.org/wiki/Modem Hope this helps.

geek_cjdnzl, Nov 27, 12:22 am

well yeh that's what a transceiver IS.....its a radio device.......that doesn't mean that an adsl modem is necessarily a transceiver UNLESS its 'wireless'......

geek_drcspy, Nov 27, 5:29 am

This is the best thread I've read for a long time, The experts disagree on one point without abusing one another. Keep it up guys, that's the way it should be, it's very helpful and interesting reading for those seeking help or advice. Well done. My 5 cents worth in layman's terms - if you're using all three jacks, e.g. there is a fax machine plugged into one jack, a phone plugged into the 2nd jack, and the computer plugged into the third jack, yes, you would need a filter in all jacks. Why? The filter, as its name implies, filters the signals from the equipments in a way that they do not interfere with the broadband signals. This is necessary so that the broadband signal remains strong, that is to say, your broadband is not slowed down or compromised. Cheers.

geek_computer_repair, Nov 27, 7:50 am

Yes, Drcspy is correct, You can only connect one adsl modem or router onto one line.

geek_computer_repair, Nov 27, 8:00 am

Filter works both ways Yes, it filters the high-frequency ADSL signal and stops it interfering with the phone. It also works in the other direction, stopping any high-frequency signals from the phone interfering with the ADSL signal. Otherwise your ADSL will disconnect every time the phone rings. And techincally, anything that converts 'baseband' digital signals to and from a 'modulated' analog signal is a MOdulator/DEModulator aka modem.
ADSL and dialup are both analog, very similar except that ADSL uses a wider range of frequencies that start just above the normal talking range.

geek_little_egypt, Nov 27, 8:00 am

One observation though about the adsl/phone filters doing nothing to the adsl signal. I have found from personal experience that those filters significantly reduce the connection speed of the adsl, even with no phone plugged into the phone side. I'm talking 50% reduction in throughput. My own advice would be use filters for phones, yes, but connect the modem/router directly to the wall socket. The less interference the better.

geek_smac, Nov 27, 10:20 am

My advice is to install a splitter This isolates ADSL data from analog
telephone on every jackpoint-no need
for filters at all & obviously no
effect on speed.

geek_deodar, Nov 27, 11:42 am