Open Control Architecture  The Open Control Architecture (OCA) is a communications protocol architecture for control, monitoring, and connection management of networked audio and video devices. Such networks are referred to as "media networks". The official specification of OCA is the Audio Engineering Society (AES) standard known as AES70-2015, or just AES70. This document will use the newer term "AES70" to refer to the standard and the architecture it specifies. AES70 is an open standard that may be used freely, without licenses, fees, or organization memberships. AES70 is intended to support media networks that combine devices from diverse manufacturers. Targeted for professional applications, AES70 is suitable for media networks of 2 to 10,000 devices, including networks with mission-critical and/or life-safety roles. AES70 is for device control, monitoring, and connection management only. It does not provide transport of media program material. However, AES70 is designed to work with virtually any media transport scheme, as the application requires. AES70's parts are separable and may be used independently. For example, a device may implement AES70 connection management, but use other means for operational control and monitoring. AES70 is termed an "architecture" because it provides the basis for definition of multiple control protocols. These protocols all share a common programming model, but vary in signalling detail, depending on the form of the underlying data transport mechanism. An AES70 application will use whichever AES70 protocol is appropriate for the communications method available. OCA, the architecture of AES70, was developed by the OCA Alliance, trade association, beginning in 2011. OCA was based on an existing control protocol named OCP, which had been created by Bosch Communications Systems in 2009 and 2010. OCP was in turn based on an embryonic control protocol standard named AES-24   developed by the AES in the early 1990s. From the outset, it was the intention of all involved to have OCA rendered into an open public standard. The Alliance completed OCA development in the Fall of 2014, and transferred the specification to the AES for rendering into a formal standard. AES70, the formal standard, was published on January 4, 2016. Today, the OCA Alliance works to develop and enhance the functionality of AES70 and to promote AES70's adoption throughout the professional media systems industry. The Alliance promotes understanding and adoption of AES70, facilitates the creation of AES70 implementations and related tools and technologies, and develops future functional enhancements of the AES70 standard.