What is Open Caching?

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A New Approach for Streaming:

Many Caches, All Connected

Since the beginning of streaming video, caches have been largely proprietary. Even when developed using open source technologies, like Squid, companies often made unique enhancements and developed their own approaches to hierarchies, session windows, and even the OS TCP stack. Now, with most streaming operators employing multiple CDNs, managing all of the caches across the different networks from a single interface is extremely complex. Open Caching is an attempt to level the paying field so content rights holders, network operators, and CDNs all have visibility into the caching network.

Specifications

Open Caching is defined by a library of documentation which specify the requirements, functions, and programming layer (APIs) of different elements of the Open Caching Network: Nodes, Request Routing, and Control Plane.

Code

In addition to the documentation, the Open Caching work at the Streaming Video Alliance has also produced reference code. These public repos provide a starting point for companies looking to implement Open Caching technologies.

Collaboration

The Open Caching specifications and code weren't developed by a single company. They were the result of a combined effort from dozens of companies since the Alliance's inception.

Functional Components

Click on a box to get more detail about the Open Caching component.

Request Routing

Request Routing is how the delivery network handles a request for content by routing it to the appropriate cache.

Provisioning

Provisioning details how to add Open Caches to an Open Caching Network through the Configuration Interface functionality.

Content Management

Content Management refers to how content within Open Caches is managed via the API interfaces (i.e., purging content)

Logging

The Logging component specifies how Open Caches capture data and make it available through API interfaces.

Security

Security addresses how the delivery of content (from cache to user and from origin to cache) is protected from theft.

Enabling Caching Interoperability

Three key components make up an Open Caching Network.

Caching Nodes

An Open Caching Node represents a caching server, within a content delivery architecture, that complies with Open Caching specifications. The cache can either be built using the specifications (such as for an ISP implementing Open Caching at the edge of their network), or Open Caching functionality can be added through plugins or other means (such as for a Content Delivery Network caches or OTT Platform origins).

Request Router

The Request Router handles the inbound request for content and forwards this request to the appropriate caching node within an environment. The Open Caching specifications identify three methods of routing: DNS, HTTP, and Manifest.

Control Plane

The Control Plane handles all communication related to management of configurations, content purging and pre-positioning, logging, and security. While the Request workflow is focused on the end user’s ability to retrieve content, the Control Plane is focused on how the different members of the video distribution chain are empowered to partake in the delivery process.

The Industry is Beginning to Notice

Open Caching Implementations

ISPs
CDNs
Content Owners
Commercial Providers

Document Spotlight

(DRAFT) Open Caching Capacity Interface

This document defines the specification for an API to retrieve capacity metrics from an Open Caching Node.

Interested in Contributing? Join the Alliance Today!

Whether you are a technology vendor, network operator, or content owner in the streaming video space, you need a seat at the Open Caching table. Come help us design and build the video caching system of the future!

The Streaming Video Alliance is a global technical consortia with contributing companies from across the video ecosystem. Open Caching is one of the Alliance’s working groups. You can learn more about the Alliance, and how to participate, by visiting the website at www.streamingvideoalliance.org.

Other Alliance Resources