Can only connect to Tiscali Broadband if I make a phone call

Have been using Tiscali Broadband for 6 months with no problem connecting to the Internet from my netbook and desktop. Yesterday however it all fell apart., unable to connect to the internet, tried rebooting Router, checked all Windows options still unable to connect. Now here's where the situation gets bizarre. I phone tiscali support, as soon as I make the call, Internet springs into life, before I have even spoken to a Tiscali Rep, he did the usual checks, nothing amiss. Ended the call to Tiscali, low and behold Internet no longer working. Then phoned BT spent over an hour going thru numerous checks, all to no avail. The outcome at the moment is this.

1. Neither the Netbook, or Desktop will connect, unless I make a phone call from my telephone.
2. Once I end the phone call Internet access stops.

As anyone gor any idea what is causing this problem, I can confirm that all worked well for 6 months no changes, additions, alterations to the internat telephone system have been made during this time.

Help

you need a new filter mine does exactly the same and im also on tiscali

Sounds like you've got what's known as a High Open. Literally, this means that the phoneline is high enough and open enough to be exposed to the elements at some point on its journey to your house. The copper wire has eroded, making it a little more difficult for the electric current to get through.

The binary signal that makes up your broadband connection only produces a tiny amount of electrical charge, the phone call produces much more. Therefore if your phone is off the hook, it effectively works like an electrical version of sink unblocker.

If this is the problem, the ffault is entirely down to BT to fix.