ocr: ProjectedRevenue OPISONA US % 350 oiliensofdolars) 30 SON 25 20 SSL 65 10 a 1997 1998 1999 2000 a 200 200% 2005 sourcoes om Figure LThis comparison of perator revenues for ISDN and Digital Subscriber Line (DSL) technolo- gies depicts more: consistent upward movement: for DSL Many factors, such as equipment costs, number of deployments, and maturity of the tech- nology, can affect operator revenues, as well as costs to operators and end users.