NTL network affecting BT lines.

[Kumagoro]

On another forum, I read a story about how a DVD player was affecting
ADSL lines over an area of 5 streets. Apparently the DVD player was
creating noise on the NTL network, which because of NTL underground amps
got on to the BT telephone lines.

What is the structure of NTL laid networks? I have always assumed that they
are digital and would use digital repeaters. Do they use amplifiers in any
part of the network? Could it be some old analogue system?

Anyone have any links about how they structure the network?

[Carl J]

The ntl network is analogue from start to finish, with digital information being encoded onto the analogue carriers.

It's partly optical fibre, amplified where required, and partly coaxial, again amplified as needed, so yes the above is possible if the ntl network is leaking RF but it really shouldn't be.

I have more information but I'm sure that someone with a bit more time can give you more complete info.

[NTLVictim]

Milton Keynes?

[Carl J]

No the network everywhere is digital carried over analogue, and the amplifiers are analogue amplifiers.

You can digitise the analogue carriers but afaik there's no cable net in the UK where this is done and it can be pointless anyway.

[Jon T]

There are a lot of unknowns in this situation, primarily to do with the DVD player and the person's setup.

For example, how can it be proven that the noise ingress to the BT network was from the NTL line and not direct pickup from the DVD player to the BT twisted pair cabling. If the Ntl cable setup at the customers premises was some how "non-standard"(i.e. customer had tried to do something with the cable feed that they shouldn't), then this could also account for noise being created on the network.

[Kumagoro]

Thanks for the replies.