Split Architectures for Carrier Class Networks

The Internet has been growing successfully for more than 20 years; the growth in demand so far has been met by introducing ever larger IP routers in operator core networks. However, in order to meet today’s steadily growing demand for Internet access and other packet-based services, we currently face the need to deploy more efficient packet networks within metro and aggregation network domains as well. Metro and aggregation networks face constantly changing business requirements today, but are limited by the protocol stacks controlling the deployed network elements (most notably IP, Ethernet, PPP among others). Dynamic service creation and management can only be achived by opening the closed monolithic environment of routing and switching devices in use today and by introducing Software Defined Networking in communication networks. 

The Internet has now truly become the essential backbone of the digital society and delivers a broad range of services, such as banking, e-commerce, social networking, media, content storage and many more. There is currently a powerful trend towards expanding coverage and usage of the Internet by going mobile. Usage by individuals is increasing steadily, both in time of use and bandwidth demands of applications in use. At the same time, 80% of the global population still lacks Internet access. Clearly, the technologies used to build the Internet need to evolve to facilitate this steady growth through sustainable, cost-efficient means. Moreover, it is commonly recognized in the technical literature that the Internet has constraints in terms of mobility, quality of service, security, and scalability (due to IP address starvation, for example, semantic overloading of IP addresses) even if patches exist for fixing some specific problems. The difficulty in removing these limits through incremental changes has motivated academic research groups in the U.S. to propose a complete rethinking of the Internet's design by adopting a clean slate approach. The genesis of this idea can be traced to the NewArch DARPA project, which reported its results in 2003. This has led to the definition and launch of the ambitious NSF FIND program and a proposal to create the Global Environment for Network Innovation (GENI) experimental infrastructure.

Around that time, the first European Projects to deal with similar problems were launched, such as like ANA (Autonomic Network Architecture) within the FET program and the FP6 IST Ambient Networks project, and developed new architecture proposals. Following FIND and the first round of FP7 Future Internet projects such as IST 4WARD, one can now state that the understanding and scientific treatment of network architectures has grown substantially in recent years, yet a silver bullet that would solve all of the IP problems and be downward compatible at the same time is still lacking.