RAP is contributing to the definition and evaluation of a new paradigm for the future Internet: a content-centric network (CCN) where, rather than interconnecting remote hosts like IP, the network directly manages the information objects that users publish, retrieve and exchange. We are building on existing CCN proposals, adopting as a starting point the concept currently promoted by Van Jacobson at the Palo Alto Research Center (PARC) (http://www.ccnx.org/).
From January 2011, our activity will contribute to an ANR project on CCN called CONNECT. The partners in CONNECT are Alcatel Lucent (leader), RAP, INRIA/Planète (Sophia), Orange Labs, Telecom ParisTech, UPMC. In the PARC vision of CCN, content is divided into packet-size chunks identified by a unique name with a particular hierarchical structure. The name and content can be cryptographically encoded and signed, providing a range of security levels. Packets in CCN carry names rather than addresses and this has a fundamental impact on the way the network works.
Security concerns are addressed at the content level, relaxing requirements on hosts and the network. Users no longer need a universally known address, greatly facilitating management of mobility and intermittent connectivity. Content is supplied under receiver control, limiting scope for denial of service attacks and similar abuse. Since chunks are self-certifying, they can be freely replicated, facilitating caching and bringing significant bandwidth economies. CCN applies to both stored content and to content that is dynamically generated, as in a telephone conversation, for example. CONNECT aims to complement the existing work on CCN with original proposals in the following three technical areas.
- Traffic control must be completely rethought: TCP is no longer applicable and queue management will require new, name-based criteria to ensure fairness and to realize service differentiation.
- Naming, routing and forwarding are partially addressed in the PARC proposal. However, choices are often expedients to facilitate overlay implementation. It is necessary to prove the name-based routing and forwarding is scalable and to design algorithms suitable for full-scale implementation.
- CCN trades off expensive bandwidth for cheap memory as content chunks can be cached within the network, avoiding the need to repeatedly fetch copies of popular items. It largely remains to define replication and caching strategies and to evaluate their performance.
CONNECT will additionally consider deployment strategies for CCN and clarify the economic arguments that make the paradigm change sufficiently compelling. This implies the study of use cases for services and applications that become possible or much more efficient because of CCN. Simulation and emulation tools will be developed to validate and test proposed algorithms and protocols.
The focus of RAP is on the design of traffic control (task leader), caching strategies and their performance and the identification of business models that ensure the viability of CCN as a replacement for IP.
