] "Telcos gain billions in service fees from [...] services
] like Call Forwarding and Call Waiting [...]. Hence, capex
] programs that shift a telco, say, from TDM to IP, as in a
] softswitch approach that might have less capital
] intensity, must absolutely preserve the revenue stream."

Essay on the impact that digital networks have on RBOC revenue streams.

Shirky: Customer-owned Networks and ZapMail