Configuration Interface API Version 2

This is the first part in a set of documents that document the Streaming Video Technology Alliance (SVTA) Configuration Interface, defining both the metadata model and APIs for entities to interchange the model. The document specifies the motivational drivers, use cases, and standards to facilitate interoperability within the content delivery network (CDN) and Open Caching ecosystems. The full document set presents a layered architecture that extends the Internet Engineering Task Force (IETF) CDN Interconnect (CDNI) metadata and capabilities models and adds publishing Application Programming Interfaces (APIs) to provide configuration management capabilities required by the CDN and open caching industries.

The IETF Content Delivery Networks Interconnection (CDNI) Metadata interface enables interconnected Content Delivery Networks (CDNs) to exchange content distribution metadata in order to enable content acquisition and delivery. This document and its sub-parts describe extensions to the CDNI Metadata Object Model as documented in “CDNI Metadata” [RFC8006] to address the complex requirements of the commercial CDN industry and to support a wider set of use cases such as Open Caching.

This document specifies the syntax and usage examples for an expression language to be used within SVTA/CDNI Metadata Interface (MI) objects. The purpose of this expression language is to enable metadata to be applied conditionally (based on aspects of an HTTP request), and to enable HTTP responses to be generated or altered dynamically.

This document specifies a set of objects extending the CDNI Metadata Model [RFC8006] to allow for metadata to be applied conditionally beyond the simple host and path matching defined in [RFC8006]. The concept of processing stages are introduced, where each stage in a CDNs processing pipeline presents an opportunity to examine requests and responses and make alterations as needed. Metadata such as caching rules can be applied conditionally (based on aspects of an HTTP request header), and HTTP responses from a source can be altered dynamically (such as adding or dropping an HTTP header). This standard leverages the expression language documented in the Metadata Expression Language (MEL) Specification.

This specification adds to the basic Cache Control metadata defined in [RFC8006], providing Content Providers and uCDNs more fine-grained control over dCDN caching. Use cases include overriding or adjusting cache-control headers from the origin, bypassing caching altogether, or altering cache keys with dynamically generated values.

This specification provides an alternative to the SourceMetadata objects defined in [RFC8006], providing greatly extended capabilities with regards to defining multiple sources, load balancing and failover rules across those sources, and a mechanism for a CDN to monitor source health and pull unhealthy sources out of rotation. Additionally, new methods are defined for authentication access to an upstream source/origin.

This specification adds to the basic client access control metadata in [RFC8006], providing Content Providers and uCDNs extended capabilities in defining location and time window restrictions. Support is also provided to define required TLS certificates and encryption levels, as well as configuration metadata for the Common Media Access Token (CAT), developed jointly by the SVTA and CTA-WAVE.

This specification defines configuration metadata objects related to controlling edge access to resources via CDNs and Open Caching systems. Configuring Cross-Origin Resource Sharing (CORS) access rules and the dynamic generation of CORS headers is a key feature of typical configurations, as are the ability to define response body compression rules, client connection timeouts, and traffic type hints for optimized caching.

This specification provides metadata defining open caching request delegation behavior for open caching node selection and request routing modes.

This specification defines a mechanism for dCDNs to define private extensions to the metadata model that are mutually agreed upon with uCDNs and Content Providers.

This is an early draft for a proposed mechanism to protect secret values (such as keys or token salt values) that are part of the Configuration Metadata.

This is part 3 in a set of documents that specify the Streaming Video Alliance (SVTA) Configuration Interface. This document presents the Simple Configuration Metadata API, which provides simple metadata retrieval and publishing capabilities as introduced in part 1 of the SVTA Configuration Interface document set.

This specification introduces the Service Configuration Model, an object layer that wraps the Host Match metadata defined in [RFC8006] with a construct defining CDN Properties (groups of hosts with shared metadata definitions) and reusable metadata definitions that can be used across all of a service’s CDN Properties. The Service Configuration represents a self-contained bundle of configuration metadata and definitions that can be published and deployed as an atomic unit with no external references. This model is defined independently of any API, and will be used as the basis for the SVTA Orchestration API and Terraform Integration.

This specification is Part 5 in the Version 2 series of the Configuration Interface documents.

This specification is Part 6 in the Version 2 series of the Configuration Interface documents.