Network Working Group M. Day Internet-Draft Cisco Expires: March 27, 2001 D. Gilletti Entera September 26, 2000 Content Distribution Network Peering Scenarios draft-day-cdnp-scenarios-00.txt Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on March 27, 2001. Copyright Notice Copyright (C) The Internet Society (2000). All Rights Reserved. Abstract This document sets forth several logical and detailed scenarios to be considered when evaluating systems and protocols for CDN peering. Pre IETF Submission Draft This ID is an interim product of work in progress within the Content Alliance. For information about the Content Alliance, see www.content-peering.org. Day & Gilletti Expires March 27, 2001 [Page 1] Internet-Draft CDNPS September 2000 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Logical Peering Scenarios . . . . . . . . . . . . . . . . . 5 2.1 Fundamental Concepts . . . . . . . . . . . . . . . . . . . . 5 2.2 Expanding Existing CDN Footprint . . . . . . . . . . . . . . 5 2.3 ACCOUNTING and REDIRECTION PEERING Across Multiple DISTIBUTING CDNs . . . . . . . . . . . . . . . . . . . . . . 6 2.4 ACCOUNTING PEERING Across Multiple DISTRIBUTING CDNs . . . . 6 2.5 PUBLISHER peers w/multiple DISTRIBUTING CDNs . . . . . . . . 6 3. Detailed Peering Scenarios . . . . . . . . . . . . . . . . . 7 3.1 Peering Establishment and Termination Scenarios . . . . . . 7 3.1.1 Peering Establishment . . . . . . . . . . . . . . . . . . . 7 3.1.2 Peering Termination . . . . . . . . . . . . . . . . . . . . 7 3.2 Distributing Content . . . . . . . . . . . . . . . . . . . . 8 3.2.1 Content Is Valuable . . . . . . . . . . . . . . . . . . . . 8 3.2.2 Distribution is Valuable . . . . . . . . . . . . . . . . . . 9 3.3 Redirecting Requests . . . . . . . . . . . . . . . . . . . . 11 3.4 Billing and Settling . . . . . . . . . . . . . . . . . . . . 11 4. Security Considerations . . . . . . . . . . . . . . . . . . 13 5. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . 14 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15 References . . . . . . . . . . . . . . . . . . . . . . . . . 16 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 16 Full Copyright Statement . . . . . . . . . . . . . . . . . . 17 Day & Gilletti Expires March 27, 2001 [Page 2] Internet-Draft CDNPS September 2000 1. Introduction This document presents several logical and detailed scenarios which are intended to describe the potential configurations that can be realized when peering CDNs. The logical scenarios describe how various entities may combine to provide a complete CDN solution. The detailed scenarios describe the actual peering interactions between the various peered entities. These scenarios answer two distinct needs: 1. To provide some concrete examples of what CDN peering is, and 2. To provide a basis for evaluating CDN peering proposals. Each of the logical peering scenarios gives an indication of how the various CDN elements are combined. From [2] these elements are: 1. REDIRECTION PEERING SYSTEM 2. DISTRIBUTION PEERING SYSTEM 3. ACCOUNTING PEERING SYSTEM The peering scenarios presented in this document are also framed by the following concepts: 1. Content Has Value 2. Distribution Has Value 3. Users Have Value At present, the references to the above concepts are only employed when they directly affect the nature of the peering scenario. A reader who is interested in a detailed description of these concepts is referred to [3]. Terms in ALL CAPS are defined in [1]. Day & Gilletti Expires March 27, 2001 [Page 3] Internet-Draft CDNPS September 2000 2. Logical Peering Scenarios This section provides several logical peering scenarios that may arise in peered CDN implementations. 2.1 Fundamental Concepts There are many potential peering configurations that can be imagined for peered CDNs. All of these configurations MUST adhere to the following concepts: There is only one FIRST-REDIRECTION system for a given set of CONTENT: In order to prevent potential conflicts this document assumes that there is one and only one FIRST-REDIRECTION SYSTEM. All other REDIRECTION SYSTEMs MUST honor this relationship. There may be more than one ACCOUNTING ENTITY: These scenarios assume that multiple ACCOUNTING ENTITIES may coexist. These entities may require specific ACCOUNTING information or they may share this information depending upon the function that they provide. There may be more than one DISTRIBUTING CDN: These scenarios assume that multiple DISTRIBUTING CDNs may coexist. They further assume that these CDNs may have peering relationships that are outside the scope of the scenario being discussed. 2.2 Expanding Existing CDN Footprint This scenario considers the case where two or more existing CDNs wish to peer in order to provide an increased scale and reach. It assumes that both of them already provide REDIRECTION, DISTRIBUTION, and ACCOUNTING services and that they will continue to provide these services to existing customers. In this scenario it is assumed that the peering relationship between all entities is comprised of; REDIRECTION PEERING, DISTRIBUTION PEERING, and ACCOUNTING PEERING. It is also worthwhile to consider that any one of these peered CDNs may also have other peering arrangements which may or may not be Day & Gilletti Expires March 27, 2001 [Page 4] Internet-Draft CDNPS September 2000 transitive to peering relationships created for the above purpose. 2.3 ACCOUNTING and REDIRECTION PEERING Across Multiple DISTIBUTING CDNs This scenario describes the case where a single entity performs ACCOUNTING and REDIRECTION functions but has no inherent DISTRIBUTION capabilities. The ACCOUNTING and REDIRECTION ENTITY must therefore peer with one or more DISTRIBUTING CDNs in order to provide a complete solution. In this scenario the ACCOUNTING and REDIRECTION ENTITY, at a minumum, would enter into REDIRECTION PEERING and ACCOUNTING PEERING relationships with each of the DISTRIBUTING CDNs. The ACCOUNTING and REDIRECTION ENTITY could also play an active role in managing the DISTRIBUTION. In this case an additional DISTRIBUTION PEERING relationships are required. It is worth noting that the REDIRECTION ENTITY discussed here is typically the FIRST-REDIRECTION SYSTEM although that is not a requirement. It is also worthwhile to consider that any one of these peered ENTITIES may also have other peering arrangements which may or may not be transitive to peering relationships created for the above purpose. 2.4 ACCOUNTING PEERING Across Multiple DISTRIBUTING CDNs This scenario describes the case where a single BILLING ENTITY which provides a settlement/clearing-house function wishes to peer w/mulitple DISTRIBUTING CDNs. For the purposes of this scenario it is not necessary to consider the specifics of REDIRECTION PEERING. In this scenario the BILLING ENTITY would enter into ACCOUNTING PEERING relationships w/one or more DISTRIBUTING CDNs. 2.5 PUBLISHER peers w/multiple DISTRIBUTING CDNs This scenario describes the case where a PUBLISHER wishes to directly enter into peering relationships w/multiple DISTRIBUTING CDNs. In this scenario it is assumed that the PUBLISHER operates as the FIRST-REDIRECTION SYSTEM for its CONTENT although it is possible that this function may be designated to one of the DISTRIBUTING CDNs. In this scenario the PUBLISHER would enter into; DISTRIBUTION PEERING, ACCOUNTING PEERING, and REDIRECTION peering with one or more DISTRIBUTING CDNs. Day & Gilletti Expires March 27, 2001 [Page 5] Internet-Draft CDNPS September 2000 3. Detailed Peering Scenarios The following text outlines what is intended to be a complete set of detailed scenarios that can arise at when peering CDNs. It provides additional detail around the following four areas: 1. Establishing/Terminating Peering 2. Distributing Content 3. Redirecting Requests 4. Billing/Settling 3.1 Peering Establishment and Termination Scenarios These items describe the scenarios that occur when CDNs are beginning or terminating some form of peering relationship. In each case, we assume that the peering relationship is being established between a BILLING ENTITY and a DISTRIBUTING CDN. The BILLING ENTITY already has a NEGOTIATED RELATIONSHIP with the relevant PUBLISHER(s), and so is already prepared to transfer money in the appropriate direction, to the appropriate party. The DISTRIBUTING CDN does not have such a connection to the relevant PUBLISHER(s). 3.1.1 Peering Establishment These items describe the situations in which CDNs are beginning some form of peering. 1. BILLING ENTITY and DISTRIBUTING CDN agree to peer DISTRIBUTION SYSTEMs for all PUBLISHERS of the BILLING ENTITY. 2. BILLING ENTITY and DISTRIBUTING CDN agree to peer DISTRIBUTION SYSTEMs for some (specified) PUBLISHER(s) of the BILLING ENTITY. 3. BILLING ENTITY and REDIRECTION ENTITY agree to peer REDIRECTION SYSTEMs for all PUBLISHERS of the BILLING CDN. 4. BILLING ENTITY and REDIRECTION ENTITY agree to peer REDIRECTION SYSTEMs for some (specified) PUBLISHER(s) of the BILLING CDN. 3.1.2 Peering Termination These items describe the situations in which CDNs are terminating some or all content peering relationships. Day & Gilletti Expires March 27, 2001 [Page 6] Internet-Draft CDNPS September 2000 1. BILLING ENTITY ends DISTRIBUTION PEERING with specified DISTRIBUTING CDN. 2. BILLING EMTITY ends REDIRECTION PEERING with specified REDIRECTION ENTITY. 3. BILLING ENTITY ends all peering with specified CDN(s). 4. BILLING ENTITY ends all peering with all CDNs. 5. DISTRIBUTING CDN ends DISTRIBUTION PEERING with specified BILLING ENTITY. 6. REDIRECTING CDN ends REDIRECTION PEERING with specified BILLING ENTITY. 7. CDN ends all peering with specified BILLING ENTITY. 8. CDN ends all peering with all BILLING ENTITIES. 3.2 Distributing Content These items describe situations in which content is being placed in a CDN. Again, these descriptions are written in terms of a BILLING ENTITY and a DISTRIBUTING CDN. We assume that any given CDN has its own mechanisms for distributing content efficiently to an appropriate set of SURROGATEs. The interactions in this situation can only take place after some form of DISTRIBUTION PEERING has been established, as described in the previous section. Interactions in this section must take account of the possibility that one of the parties may have terminated the peering relationship. 3.2.1 Content Is Valuable These items describe situations in which payment is expected to flow from the consumer of content back to the PUBLISHER via the BILLING CDN. Included in valuable-content scenarios are business models such as pay-per-view or subscriptions, but note that billing and settlement issues are treated in greater detail in [3]. BILLING ENTITY initiates change in CONTENT distribution: These items describe situations in which the BILLING ENTITY initiates some change in the distribution of one or more CONTENT objects. 1. BILLING ENTITY provides new CONTENT for distribution. 2. BILLING ENTITY signals currently distributed CONTENT has Day & Gilletti Expires March 27, 2001 [Page 7] Internet-Draft CDNPS September 2000 changed. 3. BILLING ENTITY withdraws CONTENT from distribution. BILLING ENTITY initiates change in CONTINUOUS MEDIA distribution: These items describe situations in which the BILLING ENTITY initiates some change in the distribution of CONTINUOUS MEDIA. 1. BILLING ENTITY provides new CONTINUOUS MEDIA for distribution. 2. BILLING ENTITY signals currently distributed CONTINUOUS MEDIA has changed. 3. BILLING ENTITY withdraws CONTINUOUS MEDIA from distribution. DISTRIBUTING CDN initiates change in CONTENT distribution: These items describe situations in which the DISTRIBUTING CDN initiates some change in the distribution of CONTENT. 1. DISTRIBUTING CDN requests new CONTENT for distribution. 2. DISTRIBUTION CDN drops CONTENT from distribution. DISTRIBUTING CDN initiates change in CONTINUOUS MEDIA distribution: These items describe situations in which the DISTRIBUTING CDN initiates some change in the distribution of CONTINUOUS MEDIA. 1. DISTRIBUTING CDN requests new CONTINUOUS MEDIA for distribution. 2. DISTRIBUTING CDN drops CONTINUOUS MEDIA from distribution. 3.2.2 Distribution is Valuable These items describe situations in which payment is expected to flow from the PUBLISHER to the DISTRIBUTING CDN via the BILLING ENTITY. These situations include most CDN revenue-sharing models, but note that billing and settlement issues are treated in additional detail in [3]. BILLING ENTITY initiates change in CONTENT distribution: Day & Gilletti Expires March 27, 2001 [Page 8] Internet-Draft CDNPS September 2000 These items describe situations in which the BILLING ENTITY initiates some change in the distribution of CONTENT. 1. BILLING ENTITY provides new CONTENT for distribution. 2. BILLING ENTITY signals currently distributed CONTENT has changed. BILLING ENTITY withdraws CONTENT from distribution: These items descrive the situations where the BILLING ENTITY withdraws CONTENT from distribution. BILLING ENTITY initiates change in CONTINUOUS MEDIA distribution: These items describe situations in which the BILLING ENTITY initiates some change in the distribution of CONTINUOUS MEDIA. 1. BILLING ENTITY provides new CONTINUOUS MEDIA for distribution. 2. BILLING ENTITY signals currently distributed CONTINUOUS MEDIA has changed. 3. BILLING ENTITY withdraws CONTINUOUS MEDIA from distribution. DISTRIBUTING CDN initiates change in CONTENT distribution: These items describe situations in which the DISTRIBUTING CDN initiates some change in the distribution of CONTENT. 1. DISTRIBUTING CDN requests new CONTENT for distribution. 2. DISTRIBUTING CDN drops CONTENT from distribution. DISTRIBUTING CDN initiates change in CONTINUOUS MEDIA distribution: These items describe situations in which the DISTRIBUTING CDN initiates some change in the distribution of CONTINUOUS MEDIA. 1. DISTRIBUTING CDN requests new CONTINUOUS MEDIA for distribution. 2. DISTRIBUTING CDN drops CONTINUOUS MEDIA from distribution. Day & Gilletti Expires March 27, 2001 [Page 9] Internet-Draft CDNPS September 2000 3.3 Redirecting Requests These items describe situations in which a REQUEST may need to be redirected from the FIRST-REDIRECTION CDN to another CDN. The FIRST-REDIRECTION CDN is the network that receives the request and is able to redirect that request to a REMOTE CDN if appropriate. Depending on the redirection technology involved, there may be zero, one, or n redirections possible for a given REQUEST. 1. REQUEST is for CONTENT on the FIRST-REDIRECTION CDN 2. REQUEST is for CONTENT available from a single REMOTE CDN 3. REQUEST is for CONTENT available from multiple REMOTE CDNs 4. REQUEST is for CONTENT available on both the FIRST-REDIRECTION CDN and a single REMOTE CDN 5. REQUEST is for CONTENT available on both the FIRST-REDIRECTION CDN and multiple REMOTE CDNs 6. REQUEST is for CONTENT available on both the FIRST-REDIRECTION CDN and a single REMOTE CDN, but the REMOTE CDN performance is better. 3.4 Billing and Settling This section enumerates some of the scenarios which result from considering the concepts given in [3]. 1. CONTENT is valuable and delivered by a CDN which is also the BILLING ENTITY. 2. CONTENT is valuable and delivered by another CDN that has a NEGOTIATED RELATIONSHIP with the BILLING ENTITY. 3. CONTENT is valuable and delivered by another network. The BILLING ENTITY and other CDN each have a NEGOTIATED RELATIONSHIP with a clearinghouse but have no direct relationship with each other. 4. DISTRIBUTION is valuable and performed by a CDN which is also the BILLING ENTITY. 5. DISTRIBUTION is valuable and performed by another CDN that has a NEGOTIATED RELATIONSHIP with the BILLING ENTITY. 6. DISTRIBUTION is valuable and performed by another CDN. The BILLING ENTITY and other CDN each have a NEGOTIATED RELATIONSHIP Day & Gilletti Expires March 27, 2001 [Page 10] Internet-Draft CDNPS September 2000 with a clearinghouse but have no direct relationship with each other. Day & Gilletti Expires March 27, 2001 [Page 11] Internet-Draft CDNPS September 2000 4. Security Considerations This document describes scenarios for use in evaluating CDN peering proposals. As such, it does not propose any solutions which might have security concerns. This docment assumes that any peering solutions which are derived within the context of Content Alliance effort will be compliant with the trust model given in [4]. Day & Gilletti Expires March 27, 2001 [Page 12] Internet-Draft CDNPS September 2000 5. Conclusion [Conclusion goes here] Day & Gilletti Expires March 27, 2001 [Page 13] Internet-Draft CDNPS September 2000 6. Acknowledgements The authors acknowledge the contributions and comments of Fred Douglis (AT&T), Raj Nair (Cisco), Gary Tomlinson (Entera), and John Scharber (Entera). Day & Gilletti Expires March 27, 2001 [Page 14] Internet-Draft CDNPS September 2000 References [1] Day, M. and G. Tomlinson, "A Model for Content Peering", draft-day-cdnp-model-00.txt, work in progress (work in progress), September 2000, . [2] Green, M., Cain, B. and G. Tomlinson, "Content Peering Framework", draft-green-cdnp-framework-00.txt, work in progress (work in progress), September 2000, . [3] Gilletti, D., Nair, R. and J. Scharber, "Billing Models for CDN Peering", draft-gilletti-cdnp-billing-models-00.txt (work in progress), September 2000, . [4] Aboba, B., Arkko, J. and D. Harrington, "Introduction to Accounting Management", draft-ietf-aaa-acct-06.txt (work in progress), June 2000, . Authors' Addresses Mark S. Day Cisco Systems 135 Beaver Street Waltham, MA 02452 US Phone: PHONE EMail: markday@cisco.com Don Gilletti Entera, Inc. 40971 Encyclopedia Circle Fremont, CA 94538 US Phone: +1 510 770 5281 EMail: don@entera.com Day & Gilletti Expires March 27, 2001 [Page 15] Internet-Draft CDNPS September 2000 Full Copyright Statement Copyright (C) The Internet Society (2000). All Rights Reserved. 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