Technology Specifications

Specifications

The official specification of OCA is now the AES70 standard.  The standard is in three documents that are available from the AES Standards office, as follows:

  1. AES70 Framework

Also known as OCF, this specification describes the overall architecture of AES70 and describes its mechanisms.  OCF is published as this AES document (click to go to the AES download page):

AES70-1-2015:  AES standard for Audio applications of networks – Open Control Architecture – Part 1: Framework

  1. AES70 Class Structure

Also known as OCC, this specification describes the object-oriented class structure that defines the functional repertoire (connection management, control, and monitoring) of AES70.  OCC is published as this AES document (click to go to the AES download page):

AES70-2-2015:  AES standard for Audio applications of networks – Open Control Architecture – Part 2: Class structure

Also download Appendix A in either of two forms (see below for explanation):

www.aes.org/standards/models/AES70-2-AnnexA-151112-class-structure-1.eap
or
www.aes.org/standards/models/AES70-2-AnnexA-151112-class-structure-1.xmi

  1. AES70 Protocols

Also known as OCP.1, OCP.2, etcetera, these specifications describe protocols that implement OCA control over various types of networks.

In AES70-2015, only one protocol — OCP.1 — is defined.  It is for TCP/IP networks.  Future updates to the standard will define additional protocols.  OCP.1 is published as this AES document (click to go to the AES download page):

AES70-3-2015: AES standard for Audio applications of networks – Open Control Architecture – Part 3: Protocol for TCP/IP Networks

Also download Appendix B in either of two forms (see below for explanation):

www.aes.org/standards/models/AES70-3-AnnexB-151112-tcpip-protocol-1.eap
or
www.aes.org/standards/models/AES70-3-AnnexB-151112-tcpip-protocol-1.xmi

Appendices

The two appendices listed above are Universal Modeling Language (UML) specifications.  AES70-2 Appendix A is particularly important, as it contains the entire specification of the AES70 Class Structure.

The UML files are in two forms:

  • The *.eap files are master files from a UML tool named Enterprise Architect from Sparx Systems. The usual version of the tool costs US$240, but Sparx Systems offers a free viewer, download link here.  There is also a 30-day free trial version of the full package — see the download page here.
  • The *.xmi files are master files in XMI 2.1, a standard format for representation of UML information. XML stands for “XML Metadata Interchange”.  XMI files can be opened by most UML editors, including free ones. See this Wikipedia article for more information.

Older Versions of OCA

Older versions of the OCA specification are still available.  You can request copies from Tina Lipscomb in the OCA Alliance office.  Versions available are OCA 1.0, OCA 1.1, OCA 1.2, and OCA 1.3.