Once upon a time, Octavio Alvarez <alvarezp () alvarezp ods org> said:
So the first user in a router tunes to a multicast stream. Consumption
for the ISP and all the routers in the chain to the source: same as if
it were a unicast stream. Then a second user tunes to a multicast
stream. Cost for the ISP: zero.
How does this affect peering, when some providers want bandwidth ratios
in a certain range?
I can also see how this affects the ISPs providing bandwidth to the
content providers. In our colo for example, we rate-limit customers to
the paid-for bandwidth at the colo port. With multicast however, they
could use significantly more bandwidth, because every router in our
network could potentially send the stream to many ports.