The Internet, IP, and the optical layer

IP-based services differ fundamentally in many dimensions from traditional voice-bases services. Since today\´s transport networks were optimized for these traditional services it should be expected that far-reaching changes will be needed if IP becomes dominant. This paper looks at two likely areas for change: "Transport for IP", by which we mean changes in the transport functionality available to IP-based services, and "IP for Transport", by which we mean the introduction of IP technology and concepts into the transport network.