Slide 24 of 29
Use of WDM moves the economics from transmission lines which are expensive
(labor intensive) to install, to electronics for which the cost/performance is falling
Charging is still some way off:
Issues: what to charge for: usage (as in phone system but cost of billing),
connection (flat pricing), where do premium services fit, who settles bill
(e.g. on transatlantic traffic is it user, A&R net etc.), inter-ISP settlements,
where is it measured (per hop, at edge), is it time sensitive, are there
incentives for traffic to be cooperative (e.g. TCP slow start), what is measured
(e.g. bytes/sec, loss, congestion pricing), how is it implemented.
If offer premium class then usage-sensitive pricing is
a necessity. Does not have to be onerous, even a small charge can have a
large effect. Burden of introducing charging would be heavy, especially if it
has to be accurate, reliable and auditable. Problem is that it makes something
which is already difficult to understand and manage even more complex.