ICN Research Group E. Paik Internet-Draft KT Expires: January 6, 2013 P. Mahadevan PARC M. Jang Samsung E. Cho SNU July 5, 2012 Benefits and Research Challenges of Content-Centric Networking draft-paik-icn-challenges-00.txt Abstract The objective of ICN RG is to produce documents such as a survey of diverse approaches, problem statement, and reference scenario. One of the ICN approaches is CCN (Content-Centric Networking). This document provides a qualitative analysis of CCN in terms of its technical features and the resulting benefits as well as component technologies. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Technical Features . . . . . . . . . . . . . . . . . . . . . . 3 3.1. Directly Named Content . . . . . . . . . . . . . . . . . . 4 3.2. Location Independence . . . . . . . . . . . . . . . . . . . 4 3.3. Content-Protection . . . . . . . . . . . . . . . . . . . . 4 4. Benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4.1. Network Efficiency and Performance . . . . . . . . . . . . 4 4.2. Security . . . . . . . . . . . . . . . . . . . . . . . . . 5 4.3. CAPEX and OPEX . . . . . . . . . . . . . . . . . . . . . . 5 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 6.1. Normative References . . . . . . . . . . . . . . . . . . . 6 6.2. Informative References . . . . . . . . . . . . . . . . . . 6 6.3. URL References . . . . . . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6 Paik, et al. Expires January 6, 2013 [Page 2] Internet-Draft Benefits of Content-Centric Networking July 2012 1. Introduction The objective of ICN RG is to produce documents describing different approaches, problem statement, and reference scenario. One of the ICN approaches is CCN (Content-Centric Networking). This document provides the key benefits and research challenges of CCN. 2. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. The following terms are defined. o Information-Centric Networking: Information-Centric Networking (ICN) is a new networking paradigm that shifts the emphasis from endpoints to addressing content directly, thereby enabling simple, robust and efficient content distribution in the network. o Content-Centric Networking: Content-Centric Networking (CCN), is a new network architecture that embraces ICN principles of direct content addressing. CCN architecture builds up on the fundamentals of content, names and security. o Content Delivery Network: CDN refers to Content Delivery/ Distribution Network. This document distinguishes CCN from CDN as follows: CCN protocol is a network layer architecture while CDN is a content distribution system that operates as an application layer service in today's Internet architecture. o Interest: Interest is a CCN packet type that is sent request content in a CCN network. o Content Object: In a CCN network, content that is requested by a client travels back in the form of a content object. 3. Technical Features The basic CCN operation mechanism is interest/content object exchange. Nodes wishing to receive content issue an Interest with a prefix describing the data (content) they desire. These interest packets are routed towards known content sources or producers, and as they are routed through the network any intermediate node can satisfy Paik, et al. Expires January 6, 2013 [Page 3] Internet-Draft Benefits of Content-Centric Networking July 2012 the interest with matching content objects from its cache. Each individual content object is retrieved using a single interest. The content returned is verified to be sure it is what was asked for, unmodified and published by a trusted publisher. The key features of CCN include directly named content, location independence, and content-level protection. 3.1. Directly Named Content In CCN, content is named and addressed directly unlike today networks where the emphasis is on naming end hosts. Named content travels as content objects in a CCN network. Content objects can be thought of as named data packets. 3.2. Location Independence CCN decouples content name from content location. Thus, there is no need to translate from the desired content to a location in the network. This feature allows CCN to take advantage of widespread caches and storage deployed in the network. 3.3. Content-Protection Individual pieces of content are protected rather than securing the connection between the end hosts as implemented in today's Internet. Each content object is signed by its publisher and can optionally be encrypted. This feature of protecting individual content objects allows content to be cached at any location in the network. 4. Benefits The new CCN architecture offers several significant benefits with respect to performance, cost, and ease of new application development and deployment as compared to traditional networks in use today. We address each of these in more detail in the rest of this section. 4.1. Network Efficiency and Performance Removing the dependency on location-based content retrieval allows CCN to reduce resource consumption and make the network utilization more efficient through caching. Content requestors ask for the content by name, and any CCN node along the path from the requestor to the publisher that has a matching content object in its cache can satisfy the request. Further, CCN nodes are not restricted to contacting a single source Paik, et al. Expires January 6, 2013 [Page 4] Internet-Draft Benefits of Content-Centric Networking July 2012 to receive content. They may request content from a set of sources, and can also choose the most responsive content source in order to minimize content retrieval times. 4.2. Security CCN focuses on securing individual content pieces - each content object is digitally signed and contains information about its publisher. Content objects can optionally be encrypted as well. The security model in CCN allows applications and users to determine which publishers to trust. Users can detect if an object has been modified or tampered by a malicious party before it was delivered and also be sure the publisher is one that it trusts to produce non- malicious content. Unlike today's networks that enforce security by securing the path through which unsecured content travels, CCN allows data consumers to trust the data independently of the path through which it was obtained. Additionally, by incorporating network-layer security for individual content pieces, CCN frees applications and services from focusing on securing content. This feature significantly reduces the development cost as well as complexity of most applications, including security- critical applications, such as banking services. 4.3. CAPEX and OPEX CCN reduces CAPEX and OPEX for network operators. As described in Section 4.1, CCN makes better utilization of the network and reduces CAPEX on bandwidth by reducing redundant traffic and peak-rate traffic. Secondly, CCN reduces OPEX by providing automatic management of cache with pull model of delivery. Thus, data automatically goes to where it is requested. In comparison, CDN typically require manual management of cache with push model where a content producer needs to anticipate which contents will be highly popular, as well as which clients will request a particular content, and push the desired data closest to those clients. Thirdly, CCN reduces OPEX by providing easy deployment of cache from the viewpoint of network topology. CCN allows content to cached closer to the users, including at CCN nodes at the network edge. CCN caches can also be deployed on mobile devices and inside a service provider's network. In contrast, CDN servers are typically topology- restricted and can be deployed only in certain locations such as Paik, et al. Expires January 6, 2013 [Page 5] Internet-Draft Benefits of Content-Centric Networking July 2012 peering points. Fourthly, CCN reduces OPEX by providing easy management and configuration. CCN does not need additional protocols to optimize the path, e.g., ALTO (Application Layer Traffic Optimization) protocol. Path optimization and keeping track of dynamic network conditions happens at the strategy layer in CCN - CCN has inherent network support to route around bottleneck links as well as network failures. Finally, CCN reduces OPEX by providing the same path for content requests (forward path) and response (reverse path), i.e., content objects follow the reverse of the Interest path. This aspect really helps in traffic engineering (in today's Internet architecture forward and reverse packet paths need not be the same), e.g., QoS is easier to implement in CCN networks. 5. Security Considerations TBD 6. References 6.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. 6.2. Informative References [RFC6392] Alimi, R., Rahman, A., and Y. Yang, "A Survey of In- Network Storage Systems", RFC 6392, October 2011. 6.3. URL References [CCNx] "CCNx Home Page", . Paik, et al. Expires January 6, 2013 [Page 6] Internet-Draft Benefits of Content-Centric Networking July 2012 Authors' Addresses EunKyoung Paik KT Network Research and Development Lab. KT 17 Woomyeon-dong, Seocho-gu Seoul 137-792 Korea Phone: +82-2-526-5233 Fax: +82-2-526-5200 Email: eun.paik@kt.com URI: http://mmlab.snu.ac.kr/~eun/ Priya Mahadevan Palo Alto Research Center 3333 Coyote Hill Rd Palo Alto CA 94304 USA Phone: +1-650-812-4434 Fax: +1-650-812-4471 Email: priya.mahadevan@parc.com URI: http://www.parc.com/priyamahadevan/ Myeong-Wuk Jang Samsung Electronics Co., Ltd. San 14, Nongseo-dong, Giheung-gu Yongin-si, Gyeonggi-do 446-712 Korea Phone: +82-31-280-9624 Fax: +82-31-280-9569 Email: myeong.jang@samsung.com Paik, et al. Expires January 6, 2013 [Page 7] Internet-Draft Benefits of Content-Centric Networking July 2012 Eunsang Cho Seoul National University Multimedia and Mobile Communications Lab., Seoul National Univ. 1 Gwanak-ro, Gwanak-gu Seoul 151-744 Korea Phone: +82-2-880-1832 Fax: +82-2-872-2045 Email: escho@mmlab.snu.ac.kr URI: http://mmlab.snu.ac.kr/~escho/ Paik, et al. Expires January 6, 2013 [Page 8]