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Content delivery networks and CDN interconnection
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CDN RFCs (19)
RFC 9808: Content Delivery Network Interconnection (CDNI) Capacity Capability Advertisement Extensions
Proposed Standard- A. Ryan
- B. Rosenblum
- N. Sopher
- July 2025
- IETF publication
- Web and Internet Transport
Abstract
This specification defines a set of additional Capability Objects that provide information about current downstream CDN (dCDN) utilization and specified usage limits to the delegating upstream CDN (uCDN) in order to inform traffic delegation decisions.
This document supplements the CDNI Capability Objects, defined in RFC 8008 as part of the Footprint & Capabilities Advertisement Interface (FCI), with two additional Capability Objects: FCI.CapacityLimits and FCI.Telemetry.
Abstract
This specification defines a set of additional Capability Objects that provide information about current downstream CDN (dCDN) utilization and specified usage limits to the delegating upstream CDN (uCDN) in order to inform traffic delegation decisions.
This document supplements the CDNI Capability Objects, defined in RFC 8008 as part of the Footprint & Capabilities Advertisement Interface (FCI), with two additional Capability Objects: FCI.CapacityLimits and FCI.Telemetry.
RFC 9677: Content Delivery Network Interconnection (CDNI) Metadata for Delegated Credentials
Proposed Standard- F. Fieau
- E. Stephan
- G. Bichot
- C. Neumann
- October 2024
- IETF publication
- Web and Internet Transport
Abstract
The delivery of content over HTTPS involving multiple Content Delivery Networks (CDNs) raises credential management issues. This document defines metadata in the Content Delivery Network Interconnection (CDNI) Control and Metadata interface to set up HTTPS delegation using delegated credentials from an upstream CDN (uCDN) to a downstream CDN (dCDN).
Abstract
The delivery of content over HTTPS involving multiple Content Delivery Networks (CDNs) raises credential management issues. This document defines metadata in the Content Delivery Network Interconnection (CDNI) Control and Metadata interface to set up HTTPS delegation using delegated credentials from an upstream CDN (uCDN) to a downstream CDN (dCDN).
RFC 9538: Content Delivery Network Interconnection (CDNI) Delegation Using the Automated Certificate Management Environment
Proposed Standard- F. Fieau
- E. Stephan
- S. Mishra
- February 2024
- IETF publication
- Web and Internet Transport
Abstract
This document defines metadata to support delegating the delivery of HTTPS content between two or more interconnected Content Delivery Networks (CDNs). Specifically, this document defines a Content Delivery Network Interconnection (CDNI) Metadata interface object to enable delegation of X.509 certificates leveraging delegation schemes defined in RFC 9115. Per RFC 9115, delegating entities can remain in full control of the delegation and can revoke it at any time. This avoids the need to share private cryptographic key material between the involved entities.
Abstract
This document defines metadata to support delegating the delivery of HTTPS content between two or more interconnected Content Delivery Networks (CDNs). Specifically, this document defines a Content Delivery Network Interconnection (CDNI) Metadata interface object to enable delegation of X.509 certificates leveraging delegation schemes defined in RFC 9115. Per RFC 9115, delegating entities can remain in full control of the delegation and can revoke it at any time. This avoids the need to share private cryptographic key material between the involved entities.
RFC 9388: Content Delivery Network Interconnection (CDNI) Footprint Types: Country Subdivision Code and Footprint Union
Proposed Standard- N. Sopher
- S. Mishra
- July 2023
- IETF publication
- Web and Internet Transport
Abstract
Open Caching architecture is a use case of Content Delivery Network Interconnection (CDNI) in which the commercial Content Delivery Network (CDN) is the upstream CDN (uCDN) and the ISP caching layer serves as the downstream CDN (dCDN). RFC 8006 defines footprint types that are used for footprint objects as part of the Metadata interface (MI). The footprint types are also used for the Footprint & Capabilities Advertisement interface (FCI) as defined in RFC 8008. This document defines two new footprint types. The first footprint type defined is an ISO 3166-2 country subdivision code. Defining this country subdivision code improves granularity for delegation as compared to the ISO 3166-1 country code footprint type defined in RFC 8006. The ISO 3166-2 country subdivision code is also added as a new entity domain type in the "ALTO Entity Domain Types" registry defined in Section 7.4 of RFC 9241. The second footprint type defines a footprint union to aggregate footprint objects. This allows for additive semantics over the narrowing semantics defined in Appendix B of RFC 8008 and therefore updates RFC 8008. The two new footprint types are based on the requirements raised by Open Caching but are also applicable to CDNI use cases in general.
Abstract
Open Caching architecture is a use case of Content Delivery Network Interconnection (CDNI) in which the commercial Content Delivery Network (CDN) is the upstream CDN (uCDN) and the ISP caching layer serves as the downstream CDN (dCDN). RFC 8006 defines footprint types that are used for footprint objects as part of the Metadata interface (MI). The footprint types are also used for the Footprint & Capabilities Advertisement interface (FCI) as defined in RFC 8008. This document defines two new footprint types. The first footprint type defined is an ISO 3166-2 country subdivision code. Defining this country subdivision code improves granularity for delegation as compared to the ISO 3166-1 country code footprint type defined in RFC 8006. The ISO 3166-2 country subdivision code is also added as a new entity domain type in the "ALTO Entity Domain Types" registry defined in Section 7.4 of RFC 9241. The second footprint type defines a footprint union to aggregate footprint objects. This allows for additive semantics over the narrowing semantics defined in Appendix B of RFC 8008 and therefore updates RFC 8008. The two new footprint types are based on the requirements raised by Open Caching but are also applicable to CDNI use cases in general.
RFC 9246: URI Signing for Content Delivery Network Interconnection (CDNI)
Proposed Standard- R. van Brandenburg
- K. Leung
- P. Sorber
- June 2022
- IETF publication
- Web and Internet Transport
Abstract
This document describes how the concept of URI Signing supports the content access control requirements of Content Delivery Network Interconnection (CDNI) and proposes a URI Signing method as a JSON Web Token (JWT) profile.
The proposed URI Signing method specifies the information needed to be included in the URI to transmit the signed JWT, as well as the claims needed by the signed JWT to authorize a User Agent (UA). The mechanism described can be used both in CDNI and single Content Delivery Network (CDN) scenarios.
Abstract
This document describes how the concept of URI Signing supports the content access control requirements of Content Delivery Network Interconnection (CDNI) and proposes a URI Signing method as a JSON Web Token (JWT) profile.
The proposed URI Signing method specifies the information needed to be included in the URI to transmit the signed JWT, as well as the claims needed by the signed JWT to authorize a User Agent (UA). The mechanism described can be used both in CDNI and single Content Delivery Network (CDN) scenarios.
RFC 8804: Content Delivery Network Interconnection (CDNI) Request Routing Extensions
Proposed Standard- O. Finkelman
- S. Mishra
- September 2020
- IETF publication
- Web and Internet Transport
Abstract
Open Caching architecture is a use case of Content Delivery Network Interconnection (CDNI) in which the commercial Content Delivery Network (CDN) is the upstream CDN (uCDN) and the ISP caching layer serves as the downstream CDN (dCDN). This document defines extensions to the CDNI Metadata Interface (MI) and the Footprint & Capabilities Advertisement interface (FCI). These extensions are derived from requirements raised by Open Caching but are also applicable to CDNI use cases in general.
Abstract
Open Caching architecture is a use case of Content Delivery Network Interconnection (CDNI) in which the commercial Content Delivery Network (CDN) is the upstream CDN (uCDN) and the ISP caching layer serves as the downstream CDN (dCDN). This document defines extensions to the CDNI Metadata Interface (MI) and the Footprint & Capabilities Advertisement interface (FCI). These extensions are derived from requirements raised by Open Caching but are also applicable to CDNI use cases in general.
RFC 8006: Content Delivery Network Interconnection (CDNI) Metadata
Proposed Standard- B. Niven-Jenkins
- R. Murray
- M. Caulfield
- K. Ma
- December 2016
- IETF publication
- Web and Internet Transport
Abstract
The Content Delivery Network Interconnection (CDNI) Metadata interface enables interconnected Content Delivery Networks (CDNs) to exchange content distribution metadata in order to enable content acquisition and delivery. The CDNI Metadata associated with a piece of content provides a downstream CDN with sufficient information for the downstream CDN to service content requests on behalf of an upstream CDN. This document describes both a base set of CDNI Metadata and the protocol for exchanging that metadata.
Abstract
The Content Delivery Network Interconnection (CDNI) Metadata interface enables interconnected Content Delivery Networks (CDNs) to exchange content distribution metadata in order to enable content acquisition and delivery. The CDNI Metadata associated with a piece of content provides a downstream CDN with sufficient information for the downstream CDN to service content requests on behalf of an upstream CDN. This document describes both a base set of CDNI Metadata and the protocol for exchanging that metadata.
RFC 8007: Content Delivery Network Interconnection (CDNI) Control Interface / Triggers
Proposed Standard- R. Murray
- B. Niven-Jenkins
- December 2016
- IETF publication
- Web and Internet Transport
Abstract
This document describes the part of the Content Delivery Network Interconnection (CDNI) Control interface that allows a CDN to trigger activity in an interconnected CDN that is configured to deliver content on its behalf. The upstream CDN can use this mechanism to request that the downstream CDN pre-position metadata or content or to request that it invalidate or purge metadata or content. The upstream CDN can monitor the status of activity that it has triggered in the downstream CDN.
Abstract
This document describes the part of the Content Delivery Network Interconnection (CDNI) Control interface that allows a CDN to trigger activity in an interconnected CDN that is configured to deliver content on its behalf. The upstream CDN can use this mechanism to request that the downstream CDN pre-position metadata or content or to request that it invalidate or purge metadata or content. The upstream CDN can monitor the status of activity that it has triggered in the downstream CDN.
RFC 8008: Content Delivery Network Interconnection (CDNI) Request Routing: Footprint and Capabilities Semantics
Proposed Standard- J. Seedorf
- J. Peterson
- S. Previdi
- R. van Brandenburg
- K. Ma
- December 2016
- IETF publication
- Web and Internet Transport
Abstract
This document captures the semantics of the "Footprint and Capabilities Advertisement" part of the Content Delivery Network Interconnection (CDNI) Request Routing interface, i.e., the desired meaning of "Footprint" and "Capabilities" in the CDNI context and what the "Footprint & Capabilities Advertisement interface (FCI)" offers within CDNI. The document also provides guidelines for the CDNI FCI protocol. It further defines a Base Advertisement Object, the necessary registries for capabilities and footprints, and guidelines on how these registries can be extended in the future.
Abstract
This document captures the semantics of the "Footprint and Capabilities Advertisement" part of the Content Delivery Network Interconnection (CDNI) Request Routing interface, i.e., the desired meaning of "Footprint" and "Capabilities" in the CDNI context and what the "Footprint & Capabilities Advertisement interface (FCI)" offers within CDNI. The document also provides guidelines for the CDNI FCI protocol. It further defines a Base Advertisement Object, the necessary registries for capabilities and footprints, and guidelines on how these registries can be extended in the future.
RFC 7975: Request Routing Redirection Interface for Content Delivery Network (CDN) Interconnection
Proposed Standard- B. Niven-Jenkins
- R. van Brandenburg
- October 2016
- IETF publication
- Web and Internet Transport
Abstract
The Request Routing interface comprises (1) the asynchronous advertisement of footprint and capabilities by a downstream Content Delivery Network (CDN) that allows an upstream CDN to decide whether to redirect particular user requests to that downstream CDN; and (2) the synchronous operation of an upstream CDN requesting whether a downstream CDN is prepared to accept a user request and of a downstream CDN responding with how to actually redirect the user request. This document describes an interface for the latter part, i.e., the CDNI Request Routing Redirection interface.
Abstract
The Request Routing interface comprises (1) the asynchronous advertisement of footprint and capabilities by a downstream Content Delivery Network (CDN) that allows an upstream CDN to decide whether to redirect particular user requests to that downstream CDN; and (2) the synchronous operation of an upstream CDN requesting whether a downstream CDN is prepared to accept a user request and of a downstream CDN responding with how to actually redirect the user request. This document describes an interface for the latter part, i.e., the CDNI Request Routing Redirection interface.
RFC 7937: Content Distribution Network Interconnection (CDNI) Logging Interface
Proposed Standard- F. Le Faucheur
- G. Bertrand
- I. Oprescu
- R. Peterkofsky
- August 2016
- IETF publication
- Web and Internet Transport
Abstract
This memo specifies the Logging interface between a downstream Content Distribution Network (dCDN) and an upstream CDN (uCDN) that are interconnected as per the CDN Interconnection (CDNI) framework. First, it describes a reference model for CDNI logging. Then, it specifies the CDNI Logging File format and the actual protocol for exchange of CDNI Logging Files.
Abstract
This memo specifies the Logging interface between a downstream Content Distribution Network (dCDN) and an upstream CDN (uCDN) that are interconnected as per the CDN Interconnection (CDNI) framework. First, it describes a reference model for CDNI logging. Then, it specifies the CDNI Logging File format and the actual protocol for exchange of CDNI Logging Files.
RFC 7736: Content Delivery Network Interconnection (CDNI) Media Type Registration
Informational- K. Ma
- December 2015
- IETF publication
- Web and Internet Transport
Abstract
This document defines the standard media type used by the Content Delivery Network Interconnection (CDNI) protocol suite, including the registration procedure and recommended usage of the required payload- type parameter.
Abstract
This document defines the standard media type used by the Content Delivery Network Interconnection (CDNI) protocol suite, including the registration procedure and recommended usage of the required payload- type parameter.
RFC 7336: Framework for Content Distribution Network Interconnection (CDNI)
Informational- L. Peterson
- B. Davie
- R. van Brandenburg
- August 2014
- IETF publication
- Web and Internet Transport
Abstract
This document presents a framework for Content Distribution Network Interconnection (CDNI). The purpose of the framework is to provide an overall picture of the problem space of CDNI and to describe the relationships among the various components necessary to interconnect CDNs. CDNI requires the specification of interfaces and mechanisms to address issues such as request routing, distribution metadata exchange, and logging information exchange across CDNs. The intent of this document is to outline what each interface needs to accomplish and to describe how these interfaces and mechanisms fit together, while leaving their detailed specification to other documents. This document, in combination with RFC 6707, obsoletes RFC 3466.
Abstract
This document presents a framework for Content Distribution Network Interconnection (CDNI). The purpose of the framework is to provide an overall picture of the problem space of CDNI and to describe the relationships among the various components necessary to interconnect CDNs. CDNI requires the specification of interfaces and mechanisms to address issues such as request routing, distribution metadata exchange, and logging information exchange across CDNs. The intent of this document is to outline what each interface needs to accomplish and to describe how these interfaces and mechanisms fit together, while leaving their detailed specification to other documents. This document, in combination with RFC 6707, obsoletes RFC 3466.
RFC 7337: Content Distribution Network Interconnection (CDNI) Requirements
Informational- K. Leung
- Y. Lee
- August 2014
- IETF publication
- Web and Internet Transport
Abstract
Content delivery is frequently provided by specifically architected and provisioned Content Delivery Networks (CDNs). As a result of significant growth in content delivered over IP networks, existing CDN providers are scaling up their infrastructure. Many Network Service Providers (NSPs) and Enterprise Service Providers (ESPs) are also deploying their own CDNs. To deliver contents from the Content Service Provider (CSP) to end users, the contents may traverse across multiple CDNs. This creates a need for interconnecting (previously) standalone CDNs so that they can collectively act as a single delivery platform from the CSP to the end users.
The goal of the present document is to outline the requirements for the solution and interfaces to be specified by the CDNI working group.
Abstract
Content delivery is frequently provided by specifically architected and provisioned Content Delivery Networks (CDNs). As a result of significant growth in content delivered over IP networks, existing CDN providers are scaling up their infrastructure. Many Network Service Providers (NSPs) and Enterprise Service Providers (ESPs) are also deploying their own CDNs. To deliver contents from the Content Service Provider (CSP) to end users, the contents may traverse across multiple CDNs. This creates a need for interconnecting (previously) standalone CDNs so that they can collectively act as a single delivery platform from the CSP to the end users.
The goal of the present document is to outline the requirements for the solution and interfaces to be specified by the CDNI working group.
RFC 6770: Use Cases for Content Delivery Network Interconnection
Informational- G. Bertrand
- E. Stephan
- T. Burbridge
- P. Eardley
- K. Ma
- G. Watson
- November 2012
- IETF publication
- Web and Internet Transport
Abstract
Content Delivery Networks (CDNs) are commonly used for improving the End User experience of a content delivery service while keeping cost at a reasonable level. 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 the interconnection of CDNs are specified and implemented. This document can be used to motivate the definition of the requirements to be supported by CDN Interconnection (CDNI) interfaces. It obsoletes RFC 3570. This document is not an Internet Standards Track specification; it is published for informational purposes.
Abstract
Content Delivery Networks (CDNs) are commonly used for improving the End User experience of a content delivery service while keeping cost at a reasonable level. 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 the interconnection of CDNs are specified and implemented. This document can be used to motivate the definition of the requirements to be supported by CDN Interconnection (CDNI) interfaces. It obsoletes RFC 3570. This document is not an Internet Standards Track specification; it is published for informational purposes.
RFC 6707: Content Distribution Network Interconnection (CDNI) Problem Statement
Informational- B. Niven-Jenkins
- F. Le Faucheur
- N. Bitar
- September 2012
- IETF publication
- Web and Internet Transport
Abstract
Content Delivery Networks (CDNs) provide numerous benefits for cacheable content: reduced delivery cost, improved quality of experience for End Users, and increased robustness of delivery. For these reasons, they are frequently used for large-scale content delivery. As a result, existing CDN Providers are scaling up their infrastructure, and many Network Service Providers (NSPs) are deploying their own CDNs. It is generally desirable that a given content item can be delivered to an End User regardless of that End User's location or attachment network. This is the motivation for interconnecting standalone CDNs so they can interoperate as an open content delivery infrastructure for the end-to-end delivery of content from Content Service Providers (CSPs) to End Users. However, no standards or open specifications currently exist to facilitate such CDN Interconnection.
The goal of this document is to outline the problem area of CDN Interconnection for the IETF CDNI (CDN Interconnection) working group. This document is not an Internet Standards Track specification; it is published for informational purposes.
Abstract
Content Delivery Networks (CDNs) provide numerous benefits for cacheable content: reduced delivery cost, improved quality of experience for End Users, and increased robustness of delivery. For these reasons, they are frequently used for large-scale content delivery. As a result, existing CDN Providers are scaling up their infrastructure, and many Network Service Providers (NSPs) are deploying their own CDNs. It is generally desirable that a given content item can be delivered to an End User regardless of that End User's location or attachment network. This is the motivation for interconnecting standalone CDNs so they can interoperate as an open content delivery infrastructure for the end-to-end delivery of content from Content Service Providers (CSPs) to End Users. However, no standards or open specifications currently exist to facilitate such CDN Interconnection.
The goal of this document is to outline the problem area of CDN Interconnection for the IETF CDNI (CDN Interconnection) working group. This document is not an Internet Standards Track specification; it is published for informational purposes.
RFC 3570: Content Internetworking (CDI) Scenarios
Informational- P. Rzewski
- M. Day
- D. Gilletti
- July 2003
- IETF publication
- Applications Area
Abstract
In describing content internetworking as a technology targeted for use in production networks, it is useful to provide examples of the sequence of events that may occur when two content networks decide to interconnect. The scenarios presented here seek to provide some concrete examples of what content internetworking is, and also to provide a basis for evaluating content internetworking proposals. This memo provides information for the Internet community.
Obsoleted by RFC 6770
Abstract
In describing content internetworking as a technology targeted for use in production networks, it is useful to provide examples of the sequence of events that may occur when two content networks decide to interconnect. The scenarios presented here seek to provide some concrete examples of what content internetworking is, and also to provide a basis for evaluating content internetworking proposals. This memo provides information for the Internet community.
RFC 3568: Known Content Network (CN) Request-Routing Mechanisms
Informational- A. Barbir
- B. Cain
- R. Nair
- O. Spatscheck
- July 2003
- IETF publication
- Applications Area
Abstract
This document presents a summary of Request-Routing techniques that are used to direct client requests to surrogates based on various policies and a possible set of metrics. The document covers techniques that were commonly used in the industry on or before December 2000. In this memo, the term Request-Routing represents techniques that is commonly called content routing or content redirection. In principle, Request-Routing techniques can be classified under: DNS Request-Routing, Transport-layer Request-Routing, and Application-layer Request-Routing. This memo provides information for the Internet community.
Abstract
This document presents a summary of Request-Routing techniques that are used to direct client requests to surrogates based on various policies and a possible set of metrics. The document covers techniques that were commonly used in the industry on or before December 2000. In this memo, the term Request-Routing represents techniques that is commonly called content routing or content redirection. In principle, Request-Routing techniques can be classified under: DNS Request-Routing, Transport-layer Request-Routing, and Application-layer Request-Routing. This memo provides information for the Internet community.
RFC 3466: A Model for Content Internetworking (CDI)
Informational- M. Day
- B. Cain
- G. Tomlinson
- P. Rzewski
- March 2003
- IETF publication
- Applications Area
Abstract
Content (distribution) internetworking (CDI) is the technology for interconnecting content networks, sometimes previously called "content peering" or "CDN peering". A common vocabulary helps the process of discussing such interconnection and interoperation. This document introduces content networks and content internetworking, and defines elements for such a common vocabulary. This memo provides information for the Internet community.
Obsoleted by RFC 7336
Abstract
Content (distribution) internetworking (CDI) is the technology for interconnecting content networks, sometimes previously called "content peering" or "CDN peering". A common vocabulary helps the process of discussing such interconnection and interoperation. This document introduces content networks and content internetworking, and defines elements for such a common vocabulary. This memo provides information for the Internet community.
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