So is Bellcore charging royalties for every DSL or DSLAM in existence?

If Bellcore charged royalties for DSL, would they be making a mint? 

Or would the fees prevent the technology from being used? 

How much could you reasonably charge?

I imagine that telcos in many countires would have been forced to use
DSL to stay competitive against cable or satellite based ISPs.

Also, many countries that wanted to roll out broadband internet access
would have been faced with the choice of building an extensive cable
or satellite network or building a DSL network and paying the
royalties. In summary, this technology seems so useful it seems wier
that Bellcore aren't a massively profitable company living off the
patents surrounding DSL.

I've checked out the wikipedia site. Doesn't seem to tell me much.

DSL is now (almost) everywhere in the UK and I guess that it must be
really hurting the cable companies.

I've also wondered about whether there is a royalty cost to BT
(British Telecom), the main provider.

Maybe the patents have expired or are ineffective?

I once heard that Xerox made a small royalty on Ethernet

- just once, and from a guy in Xerox

My understanding is for the DSL box or hardware, usually royalty is
not collect, but if you add in features like QoS, then you shell out
the royalty.

For Ethernet, it is paid to 3Com, they hold all those early patent, as
the founder was ex Xerox PARC engineer.