Scalability and Performance of the AMWA IS-04 and IS-05 NMOS Specifications for Networked Media

摘要

The use of IP networks for professional AV media is becoming prevalent within the broadcast industry with standards such as SMPTE ST 2110 now available for streaming uncompressed video, audio and ancillary data. To allow full interoperability between different manufacturers' equipment, common methods for discovery, registration and connection management of media devices are essential. The Advanced Media Workflow Association (AMWA) has been developing the Networked Media Open Specifications (NMOS) for this purpose, leading to the publication of two interface specifications: IS-04 for discovery/registration of NMOS Nodes and IS-05 for management of connections between Nodes. These use RESTful APIs to communicate between applications and devices and are gaining widespread adoption. — However, a key requirement within the industry is that these APIs scale successfully in the very large installations typical of real world deployments. To help address this, Sony has been leading an AMWA NMOS Scalability study to test these protocols for installations comprising thousands of media devices. — The study includes: confirming that operations such as the registration of thousands of Nodes can occur within an acceptable timeframe; testing recovery of the Registry after a failure; testing behaviour with multiple clustered Registries; testing different methods of Registry discovery; testing connection management at scale; and confirming behaviour for architectures with redundant network interfaces. The test suite has been shared with other AMWA members and tests have been repeated and confirmed with different Registry and Node implementations. — This paper describes our test methodology, provides several results, discusses their implications, identifies best practices for deployment and suggests whether further API enhancements may be beneficial.