What are the Services of an Information-centric Network, and Who Provides Them? Anders Eriksson, B¨ orje Ohlman, Karl- ˚ Ake Persson Ericsson Research Ericsson Stockholm, Sweden {Anders.E.Eriksson, Borje.Ohlman, Karl-Ake.Persson}@ericsson.com Abstract—Various Information-centric Network (ICN) ser- vices have been proposed in the literature, such as content distribution, publish-subscribe, event notification, and search. Such services have traditionally been described as separate from one another, and little attention has been given to the issue of a common ICN architecture within which they all can interact efficiently. In this paper, we describe how information-centric services can interact within one archi- tectural framework to provide a rich ICN service offering related to Information Objects, such as content and data objects. We give examples of how the architecture can support various application domains, for example content distribution, machine-to-machine communication, and interactive and live streaming applications. We also propose the business role of an ICN Service Provider, which adds value by composing a service offering of a variety of ICN services. The contribution of the paper is to highlight the need for efficient interaction between multiple ICN services in order to provide an attractive and complete ICN service offering, to describe an architecture for such interaction, and to identify the business role of an ICN Service Provider. Keywords-Information-centric; architecture; service model. I. I NTRODUCTION Information-Centric Networks (ICN) is a relatively new research field. There are currently a number of approaches being developed, e.g., NetInf [1], CCN/NDN [7], PSIRP [8]. There have also been some attempts to define common mechanisms and characteristics that should be generic to ICN [2]. In this paper, we make an attempt to define ICN at a mechanism-independent service level. The core idea of ICN is to move the focus from devices and network entities to the Information Objects (IOs) themselves, i.e., content, data files, RFID tags, web pages, sensor data, application instances, etc. ICN should thus be defined by how we can interact with these IOs, i.e., by defining the services needed to interact with them. The service offered by an IP network is primarily store- and-forwarding of IP packets. What are, then, the services offered by an Information-Centric Network? Judging from the papers published on this topic summarized in [2], an ICN primarily offers an optimized transfer service for IOs, similar to that of http. Using this service, clients can retrieve named IOs from storage or streaming servers in an anycast fashion. Some network architectures also offer a subscribe and event notification service. Other services needed for a full-blown ICN, like an advertisement service, are not, as far as we have seen, described in the proposed approaches. Much of the ICN research focus on an http-like transfer service which results in a research agenda with topics and mechanisms well-known from TCP/IP research, such as routing, congestion control, mobility management, etc., although with an information-centric touch. In this paper, we argue that there is more to Information-Centric Networks than this. An ICN allows for a significantly richer service offering in addition to that of transfer of IOs. A key ICN service is search for IOs and metadata associated with IOs. Traditional Internet search engines offer unpredictable per- formance in terms of when or whether a published resource will be reachable via search. An ICN search service should offer timely reachability of published IOs. One of the things we discuss in this paper is how the interaction between an ICN Search Service and other ICN services, such as Event Notification, Advertisement, and Storage allows for a more predictable Search Service. When discussing ICN services, it is of course relevant to describe business roles, service providers, and interdomain interfaces. The paper outlines a business model for ICN using open and non-proprietary interdomain interfaces. The remainder of this paper is organized as follows: Section II describes a horizontal application-independent ICN infrastructure. Section III describes the semantics of the interaction between ICN services on the one hand, and the interaction between these services and the ICN Publishers and Subscribers on the other hand. Section IV describes how this interaction model applies to different use cases. Sec- tion V describes business roles and interdomain interfaces between ICN services and service providers, as well as ICN metadata relevant for these interfaces. Section VI discusses related work. Section VII draws conclusions and proposes next steps in the development of an ICN service model. 11 Copyright (c) IARIA, 2012. ISBN: 978-1-61208-238-7 AP2PS 2012 : The Fourth International Conference on Advances in P2P Systems