Many scientists in the networking field are excited by what has been initially called Content-Centric Networking. Recently, two national funding agencies have announced large projects in this area: Named Data Networking by the US NSF, and Réseaux Orientés au Contenu by the French ANR. Here is my focus on this topic.
It seems that new generations of Internet routers will have the capacity to cache content. Their future deployment represents an opportunity to revisit the techniques that are currently used in the Internet to deliver content. So far, the flaws of the Internet and the drawbacks of IP-layer multicast have been overcome by Content Delivery Networks (CDN) such as the Akamai network. In brief, a CDN is comprised of around a hundred of thousands servers, which are located as near as possible of end-users' networks. These servers are in charge of storing and delivering the content of their clients (here, some service providers) to the end users. Somehow, the predominance of CDNs is a part of the network neutrality debate, because small service providers can not have the same quality of service than Akamai-powered incumbents.
The seminal works done at the Palo Alto Research Center (PARC) addressed the fundamental issue of routing queries and data based on content name. These works enable the exploitation of the caching feature of new Caching Routers. However, the management of thousands of in-network Caching Routers is still an open question, which has to take into account:
- the distributed nature of this caching system. Contrarily to the centralized management of CDN, the envisioned network of Caching Routers is by nature distributed: every Caching Routers is expected to decide by itself whether a content that it routes should be cached or not. Moreover, a claimed objective is to retain the simplicity and scalability of current Internet protocols. Actually, Internet works because it is simple, let's stick to this approach.
- the complexity of the peering relationships between autonomous networks in the Internet. Internet is a loosely-coordinated aggregation of networks. The equilibrium of the whole Internet depends on the selfish actions of every network. The deployment of Caching Routers is among the few events that have the potential to significantly impact the behavior of inter-network relationships, and affect the global Internet.
- the evolution of content. Cisco claims that video traffic will represent 90% of the overall Internet traffic in 2014. If video clips à-la-YouTube can be treated as a classic cacheable content object, many other forms of video services are emerging. In particular, time-shifted streaming is becoming a major trend, for TV of course, but also for potential life-streaming systems (lifecasting). As we have recently showed, these new forms of video consumption represents a challenge for network management.