Pharos: An architecture for next-generation core optical networks

Introduction The last decade has seen some dramatic changes in the demands placed on core networks. Data has permanently replaced voice as the dominant traffic unit. The growth of applications like file sharing and storage area networking took many by surprise. Video distribution, a relatively old application, is now being delivered via packet technology, changing traffic profiles even for traditional services. The shift in dominance from voice to data traffic has many consequences. In the data world, applications, hardware, and software change rapidly. We are seeing an unprecedented unpredictability and variability in traffic patterns. This means network operators must maintain an infrastructure that quickly adapts to changing subscriber demands, and contain infrastructure costs by efficiently applying network resources to meet those demands. Current core network transport equipment supports high-capacity global-scale core networks by relying on higher speed interfaces such as 40 and 100 Gb/s. This is necessary but in and of itself not sufficient. Today, it takes considerable time and human involvement to provision a core network to accommodate new service demands or exploit new resources. Agile, autonomous, resource management is imperative for the next-generation network. Today's core network architectures are based on static point-to-point transport infrastructure. Higher-layer services are isolated within their place in the traditional Open Systems Interconnection (OSI) network stack. While the stack has clear benefits in collecting conceptually similar functions into layers and invoking a service model between them, stovepiped management has resulted in multiple parallel networks within a single network operator's infrastructure.