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Is this a faulty ADSL line? 1

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jonnyknowsbest

Technical User
Feb 3, 2004
163
GB
We have had Demon HomeOffice 8000 installed at work but we cannot get the router (we have tried 2 routers in total) to sync with the exchange UNLESS we plug a phone into the filter and make a phone call on it. Then as soon as we hang up the phone, the router loses sync.

I have tested the following:
1) Phone plugged straight in to phone line (with no filter - Phone works fine, no static
2) Phone plugged into filter only (no router) - Phone works fine, no static
3) Phone plugged into filter with router - Phone works ok for first couple of seconds, then small amount of static.

Has anyone else experienced this?
 
I would like to add, i have tried a total of 6 different microfilters
 
Never experienced it but here's a couple of ideas.

Does the router(s) log throw any light on the situation?

Contact ISP & phone company and report the problem.

Finally.
Sounds to me like a wiring fault - which could be at your end.

[navy]When I married "Miss Right" I didn't realise her first name was 'always'. LOL[/navy]
 
I never have seen this problem on a ADSL but have seen it on a 4 wire data ckt. that did not have sealing current on the ckt. This is caused by bad green connections that will look like a open on till current is applied across the connection. On a 4 wire data ckt. this will cause app. 23 db lost, I would call my telco to have the line checked.
 
We had exactly the same problem on our ADSL line (BTBroadband) at home a couple of years ago. It was traced to a faulty connection on the BT side of things.

I cannot remember exactly what the solution was, but I do know that on one occasion a fault was traced to the fuses on a pole not being fully pushed home.

Paul
 
Sounds like bad filter(s) or a problem in the dsl line.... Since DSL is digital there is positively NO filter ciruit in the DSL side of the DSL filter... Actual filters used in DSL filter are actually a passive band-stop filter on the PHONE side of the line.

You can actually surf into the dsl modem and look at the dsl line characteristics (aka footprint), such as bandwidth, signal/noise, attenuation, power, etc..

P2E
 
Here's a few points to ponder...

1. Are you plugging the router into the BT Master socket?

2. Is this socket an NTE5? If yes, what's the scenario if you plug router only into the test socket via a known good filter?

3. If you are not totally sure about the filters you're using, get an old two-wire 56K modem lead and plug that in instead of the normal RJ11-to-RJ11 lead.

4. Is this a Demon supplied router, and have Demon run any tests on your line?

5. Give us router line stats, as that will help us provide you with further info etc.


ROGER - G0AOZ.
 
G0AOZ, maybe step it down a notch, son.. Using industry acronyms/buzz-terms (BT Master, NTE5, router line stats, etc) with non-industry people is comparable to speaking chinese to the french.

I am in the industry and I dont even understand your #3 reply. Did you mean to say, try another modem/telephone phone cord?

Also, JohnnyKB, call the ISP report your problem and they will send a tech out to repair their wiring problem. I suspect if it an ISP problem, doing anything at you home, other than taking the phone off-hook, will have little impact on getting you online consistently...

Consider this, the ISP charges you monthly for the massive sums of money they spend on test equipement, integrating & developing diagnostic tools, training and support.

P2E
 
I was assuming the poster was located in the U.K. since he stated he was using Demon HomeOffice 8000.

I was under the impression this WAS a reasonably technically orientated forum. My mistake...

BT = British Telecommunications. One of the main telecoms providers in the U.K.

Master or Master Socket = Main telephone socket within customer's premises that connects to the wires coming from the telephone exchange. "Master" is used to distinguish it from a "Secondary" socket which doesn't have bell capacitor, spark gap or bleed resistor circuitry inside.

NTE5 = A specific type of Master socket fitted by telecoms companies (BT included), which if wired correctly, enables the customer to disconnect all extension telephone wiring within the premises, when the lower half of the faceplate is unscrewed and pulled out. This is very useful when trying to identify where faults are likely to be located.

Router Line Stats = Most routers provide statistics relating to the ADSL (Broadband) line between the exchange and customer's premises. These statistics will give, amongst others, SNR Margin (Signal-to-Noise Ratio) and ATTN (Loop Attenuation figures. These figures are useful in establishing how capable the line is for carrying a Broadband signal, and if that signal is likely to provide a solid Internet connection. E.g. If you said your DS SNR Margin was 4dB, your DS ATTN 63dB, and you had a 1Mbps circuit provided, I could immediately tell you that you'd probably not have a stable connection, if indeed you'd got one at all!!

RJ11 = Descriptive reference to the small (normally clear plastic) telephone jack used to connect the router to the ADSL microfilter. How else to describe it without waffling on for three or four sentences??


With a normal USB modem or router installation in the U.K., the customer will be provided with a lead to connect the modem or router to the telephone line. This lead will have RJ11 connectors on BOTH ends. One end fits into the modem or router, the other end must be fitted into the relevant socket on the ADSL microfilter. If we go back a few years to the time when good ol' fashioned dialup modems were the only way for most folks to connect to the Internet, the lead we used had an RJ11 at the modem end and a conventional telephone plug (commonly known as an LJU) at the other end. No filters were required, and the lead was plugged directly into a convenient phone socket.

Now, if the poster was concerned about a possible problem with any of his ADSL microfilters, what I was suggesting was to use one of these old modem leads which could be directly plugged into the Master socket thereby eliminating the need for a filter. On an ADSL enabled line, the filter is only needed for telephone handsets, fax machine, burglar alarm circuits, Sky boxes etc. You DON'T need a filter for a modem or router.

Does that make it any clearer?


ROGER - G0AOZ.
 
Got to the bottom of this.

Although it was a separate analogue line, it was being routed through our "speed diallers" and the circuit was only being made when a telephone call was made. The ADSL signal was not enough to close the loop.

In the end we had to change the dip switches on the particular speed dialler box to allow the ADSL line to be permanantly connected.

Thanks to everyone who replied.

Cheers
 
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