--- 1/draft-ietf-cdni-use-cases-07.txt 2012-06-18 11:14:11.937343333 +0200 +++ 2/draft-ietf-cdni-use-cases-08.txt 2012-06-18 11:14:11.965342567 +0200 @@ -1,25 +1,25 @@ Internet Engineering Task Force G. Bertrand, Ed. Internet-Draft E. Stephan Obsoletes: 3570 (if approved) France Telecom - Orange Intended status: Informational T. Burbridge -Expires: December 13, 2012 P. Eardley +Expires: December 20, 2012 P. Eardley BT K. Ma Azuki Systems, Inc. G. Watson Alcatel-Lucent (Velocix) - June 11, 2012 + June 18, 2012 Use Cases for Content Delivery Network Interconnection - draft-ietf-cdni-use-cases-07 + draft-ietf-cdni-use-cases-08 Abstract Content Delivery Networks (CDNs) are commonly used for improving the End User experience of a content delivery service, at a reasonable cost. This document focuses on use cases that correspond to identified industry needs and that are expected to be realized once open interfaces and protocols supporting interconnection of CDNs are specified and implemented. The document can be used to guide the definition of the requirements to be supported by CDN Interconnection @@ -33,21 +33,21 @@ 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/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on December 13, 2012. + This Internet-Draft will expire on December 20, 2012. Copyright Notice Copyright (c) 2012 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents @@ -61,38 +61,38 @@ 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 1.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 3 1.3. Rationale for Multi-CDN Systems . . . . . . . . . . . . . 4 2. Footprint Extension Use Cases . . . . . . . . . . . . . . . . 6 2.1. Geographic Extension . . . . . . . . . . . . . . . . . . . 6 2.2. Inter-Affiliates Interconnection . . . . . . . . . . . . . 6 2.3. ISP Handling of Third-Party Content . . . . . . . . . . . 7 2.4. Nomadic Users . . . . . . . . . . . . . . . . . . . . . . 7 - 3. Offload Use Cases . . . . . . . . . . . . . . . . . . . . . . 8 + 3. Offload Use Cases . . . . . . . . . . . . . . . . . . . . . . 9 3.1. Overload Handling and Dimensioning . . . . . . . . . . . . 9 3.2. Resiliency . . . . . . . . . . . . . . . . . . . . . . . . 9 3.2.1. Failure of Content Delivery Resources . . . . . . . . 9 3.2.2. Content Acquisition Resiliency . . . . . . . . . . . . 10 4. CDN Capability Use Cases . . . . . . . . . . . . . . . . . . . 10 - 4.1. Device and Network Technology Extension . . . . . . . . . 10 + 4.1. Device and Network Technology Extension . . . . . . . . . 11 4.2. Technology and Vendor Interoperability . . . . . . . . . . 11 - 4.3. QoE and QoS Improvement . . . . . . . . . . . . . . . . . 11 + 4.3. QoE and QoS Improvement . . . . . . . . . . . . . . . . . 12 5. Enforcement of Content Delivery Policy . . . . . . . . . . . . 12 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 12 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 8. Security Considerations . . . . . . . . . . . . . . . . . . . 12 - 9. Informative References . . . . . . . . . . . . . . . . . . . . 12 + 9. Informative References . . . . . . . . . . . . . . . . . . . . 13 Appendix A. Content Service Providers' Delivery Policies . . . . 13 A.1. Content Delivery Policy Enforcement . . . . . . . . . . . 13 A.2. Secure Access . . . . . . . . . . . . . . . . . . . . . . 14 - A.3. Branding . . . . . . . . . . . . . . . . . . . . . . . . . 14 + A.3. Branding . . . . . . . . . . . . . . . . . . . . . . . . . 15 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15 1. Introduction Content Delivery Networks (CDNs) are commonly used for improving the End User experience of a content delivery service, at a reasonable cost. This document focuses on use cases that correspond to identified industry needs and that are expected to be realized once open interfaces and protocols supporting interconnection of CDNs are specified and implemented. The document can be used to guide the @@ -113,21 +113,21 @@ o CDN Offload Use Cases (Section 3) o CDN Capability Use Cases (Section 4) Then, the document highlights the need for interoperability in order to exchange and enforce content delivery policies (Section 5). 1.1. Terminology We adopt the terminology described in - [I-D.ietf-cdni-problem-statement], and [I-D.davie-cdni-framework]. + [I-D.ietf-cdni-problem-statement], and [I-D.ietf-cdni-framework]. We extend this terminology with the following terms. Access CDN: A CDN that includes Surrogates in the same administrative network as the end-user. Such CDN can use accurate information on the End User's network context to provide valued-added Content Delivery Services to Content Service Providers. @@ -352,30 +352,34 @@ `--'--'--' `--'--'--' | | +------------+ +---------------+ + EU A (home)| | EU A (nomadic)| +------------+ +---------------+ === CDN Interconnection Figure 2 The alternate CDN (CDN-B) is allowed to distribute the content of CSP - A to End User A; however, no other End Users in the region of CDN-B - are allowed to retrieve the content unless they too have such an - agreement for nomadic access to content. + A to End User A; however, no other End Users (e.g., End User B) in + the region of CDN-B are allowed to retrieve the content unless they + too have such an agreement for nomadic access to content. Note that + the mechanism on how to enforce that End User A is allowed to + retrieve the content but End User B is not, is not part of the + discussion in this memo. Depending on CSP's content delivery policies (see Appendix A.1), a user moving to a different geographic region may be subject to geo- blocking content delivery restrictions. In this case, he/she may not be allowed to access some pieces of content. 3. Offload Use Cases + 3.1. Overload Handling and Dimensioning A CDN is likely to be dimensioned to support an expected maximum traffic load. However, unexpected spikes in content popularity (flash crowd) may drive load beyond the expected peak. The prime recurrent time peaks of content distribution may differ between two CDNs. Taking advantage of the different traffic peak times, a CDN may interconnect with another CDN to increase its effective capacity during the peak of traffic. This brings dimensioning savings to the CDNs as they can use the resources of each other during their @@ -543,24 +546,24 @@ This memo includes no request to IANA. 8. Security Considerations This document focuses on the motivational use cases for CDN Interconnection, and does not analyze the associated threats. Those are discussed in [I-D.ietf-cdni-problem-statement]. 9. Informative References - [I-D.davie-cdni-framework] - Davie, B. and L. Peterson, "Framework for CDN - Interconnection", draft-davie-cdni-framework-01 (work in - progress), October 2011. + [I-D.ietf-cdni-framework] + Peterson, L. and B. Davie, "Framework for CDN + Interconnection", draft-ietf-cdni-framework-00 (work in + progress), April 2012. [I-D.ietf-cdni-problem-statement] Niven-Jenkins, B., Faucheur, F., and N. Bitar, "Content Distribution Network Interconnection (CDNI) Problem Statement", draft-ietf-cdni-problem-statement-06 (work in progress), May 2012. [I-D.ietf-cdni-requirements] Leung, K. and Y. Lee, "Content Distribution Network Interconnection (CDNI) Requirements",