Last week we looked at what Interoperability is, and mentioned the two organisations leading this charge in broadcasting: the AVnu Alliance and Ravenna.
This week, let’s look at Ravenna: officially launched at IBC 2010 and is described as “a technology for real-time transport of audio and other media data in IP-based network environments.”
Its aim is to adapt standard network protocols for use primarily in the professional broadcast market, and uses an internet streaming technology which is controlled by Internet Engineering Task Force (IETF) protocols such as RTP, SRP and SIP (these are the protocols used by the likes of Spotify, YouTube and internet radio.)
Proposed by ALC Networx, Ravenna is an open standard layer 3 protocol. Although intended for an Ethernet infrastructure, its use of IP packets abstracts it from the underlying network fabric, extending its reach beyond LANs to public networks, and even the internet. In other words, there are no geographihcal limits to this technology – the use of standard protocols makes it possible to leverage existing IP infrastructures.
These are clear and obvious benefits: a global system which uses exisiting infrastructure architecture, although the performance of individual connections is limited by the bandwidth of its weakest segment. Synchronization is achieved through IEEE1588-2008 (PTPv2 Precision Time Protocol), another standard protocol which provides the ability to synchronise local clocks to a precision as defined in AES-11.
ALC Networx has attempted to address the issue of interoperability by encouraging the formation of a Ravenna ecosystem, and they have already signed up a healthy collection of manufacturers including Lawo, Telos, Genelec, Merging Technologies and Sonifex.
These companies are developing these existing protocols, and at NAB 2012 proved the validity of this approach, ALC-Networx and Axia demonstrated, at NAB 2012, mutually interoperable modes of Ravenna and Livewire (Axia have been selling a similar network technology, Livewire, since 2003.)
More information in Ravenna can be found here.
We will look at the AVnu Alliance in more detail next week.
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