I had a phone call from a widowed friend to say her Internet was down. She had spent about 2 hours on the phone to her ISP (Clear) and all they could suggest was that her Modem (a Dynalink RTA1320) was faulty

I called yesterday and and found the Modem power LED was steady and green, the Ethernet and DSL lights were on but the PPP light would flash 5 or 6 times, then go out and repeat 10 seconds or so later

I was able to Login and retrieve the settings and then hooked up another RTA1320 that I had brought with me.

Exactly the same result… Hmmmmm… so not modem

I then hooked up a S/H D-Link DSL502T that I had also brought with me and after initialising, it was OK and going

What the Hell!!

I reconnected the Dynalink and still the same problem.

Next I unlugged the other 3 phones on the network. 1 x Panasonic Cordless and 2 x Analogue

After 20 secs or so the Modem fully initialised so we had an external fault somewhere.

I reconnected the 2 Analogue Phones (and their filters of course) and everything still worked 100%

So I plugged in the cordless and the fault returned.

A bit of head scratching, then as a test I swapped the filter on the Cordless (a D-Link filter) for one on the nearest Analogue phone (a Dynalink Filter) and the modem was rock solid.

I tried the other 2 modems again and they were both operating 100%

I left it like that, but I suspect that perhaps something in the Cordless Phone did not like the D-Link filter

Spurious RF perhaps?

I have no idea, but it works and I am happy with that.