COMIT: Active Content Management at Internet Scale

The Internet is currently passively pushing bits between end-host machines, be it servers, fixed or mobile user devices, or sensors. The network does not "understand" what is being transferred, i.e., it is not content-aware. This agnostic mode of operation affects several of its key functionalities, for example, efficient content distribution and content-aware traffic engineering. As a result, the network is not able to cope well with the exponentially increasing amounts of multimedia content access which constitute the major mode of use in recent years. Fixed and mobile network providers keep continuously upgrading their infrastructures but the situation has become unsustainable due to their eroding profit margins. There is an urgent need to rethink traffic management under the umbrella of active content management, rather than passive content transfer, allowing ISPs to control traffic better and achieve a sustainable model for the long-term evolution of their networks. New approaches that maximise traffic localisation are essential for long-term global network sustainability.

In this context, Information-Centric Networking (ICN) has emerged as an alternative to the current host-to-host communication paradigm and proposes direct communication between user applications and the content itself, putting the actual information or content in the forefront and disregarding location. In ICN, the network transfers individual, identifiable content chunks, instead of data containers, i.e. packets, with opaque data. Contents are identified by name and relevant packets contain a part of a content chunk; the latter can be retrieved from the hosting server or from an in-network router cache, given that in-network caching is a key aspect of the ICN paradigm. Popular content tends to stay longer in network caches and "anycast routing" based on content names retrieves the closest copy to the user. This increases dramatically traffic localisation, avoids flash crowd effects and gives to network providers control over the information transferred, allowing them to engineer their networks based on the actual demand for named content.

Despite the considerable amount of effort that has been invested to date by the research community in location-independent routing based on content names, a widely acceptable and scalable solution is yet to be found. Any naming scheme would have to be able to accommodate 10**12 or more objects and content resolution and routing based solely on content names raises serious scalability concerns. In addition, the current IP-based Internet represents a massive infrastructure that cannot be easily replaced by a new, clean slate design. Having this in mind, and given our considerable research experience in the ICN area, we believe it is possible to achieve the ICN benefits of traffic localisation and sustainable network evolution without radical ICN approaches but by introducing, in an evolutionary manner, a "content layer" in the Internet architecture which will operate above the current network layer and below the transport layer, i.e. layer 3.5.

This layer will intercept communication, will produce unique location-independent names for requested content and will store the latter within the network according to sophisticated caching policies. Content will be accessed in an anycast fashion using ICN style of operation but overlaid over IP, exploiting the existence of scalable IP-based routing, maintaining full backwards compatibility and protecting current investment. In addition, congestion control will be dealt with in a hop-by-hop rather than an end-to-end basis within the content layer, maintaining at the same time compatibility with current end-to-end operation while maximizing the use of available network resources, increasing user quality of experience and paving the way for future Internet applications with stringent real-time requirements.

The emergence of Content Distribution Networks (CDNs) and of relevant market players served well the purpose of bringing (static) content closer to the user. However, modern applications (as well as anticipated highly-interactive future forms of communication) do not simply call for storage-localisation of static content only, but instead for more efficient communication platforms that will be able to support high-volumes of real-time streaming in conjunction with interactive traffic and other demanding applications.

At present, ISPs operate as passive "bit pushers", struggling to keep their networks running by throwing more and more capacity or by deploying their own CDN infrastructures. Backwards compatibility requirements and homogeneity among technologies used in the Internet has led to the ossification of the architecture and has set a ceiling on the innovation allowed. Given the observed exponential traffic increase, the situation is going to simply become unsustainable. Mobile data traffic is expected to increase 26-fold by 2015, according to Cisco's predictions, with not only fixed and mobile usage replacing TV and radio but also through other, yet unforeseen, applications. Bottlenecks are already appearing in the backhauls of cellular networks (e.g., the O2 London outage in 2009) due to the skyrocketing mobile data traffic.

There is an urgent need to rethink traffic management under the umbrella of active content management, rather than passive content transfer, allowing ISPs to control traffic better and achieve a sustainable model for the long-term evolution of their networks.

Timescale of projected impact: Our research is targeting the period of the next 5-20 years. Within this period, we envision an explosion in the number of Internet endpoints, with everything getting connected to the Internet and resulting to an Internet of Things. Those "things" will include a variety of devices, from home appliances to vehicles to small healthcare devices to help the elderly. Given the increasingly stringent requirements of applications, traffic will need to be identified, classified and potentially prioritised in a well-engineered network. The proposed approach and the related protocols will pave the way for the transition to content-aware traffic engineering for ISPs, which is now becoming a necessity rather than an option in order to guarantee sustainable network evolution. This project will build the enabling technology and hence, the path to the establishment of such infrastructures and to the expected revolution of the related applications.

Below, we provide a list of who we expect our research to benefit and how.

* ISPs: The active content management approach proposed here has the potential to give a more active role to ISPs by giving them the opportunity to actively manage the content they are transferring, rather than simply adjusting storage and bandwidth resources (and therefore, investment) according to expected demand.

* Academic community: The academic community has been looking into ways of bringing the ICN benefits to the attention of the industrial players. However, given that no viable pathway has been found yet, the ICN research field is running the risk of being considered unsuccessful and, eventually, become obsolete. The proposed viable approach for realising the benefits of ICN, and of content-aware networking in general, will pave the way to new related fields of research.

* Society: This shift to active content management will open up the road to innovation in terms of application design. The Internet architecture will become more sustainable and able to foster new application platforms and therefore, will contribute to job creation and economic prosperity. Implementation, marketing and operation of real-time, interactive applications both in the fixed and in the mobile world will not be a taboo discussion among Internet researchers and engineers but will become a reality.