Paper Session 1: New Directions in Streaming Audio
Tim Shuttleworth (Renkus Heinz), session moderator
Friday, Nov. 18, 10:00am, CalIT2 Auditorium
10:00. Alexander Carôt and Gerald Schuller: Applying Video to Low Delayed Audio Streams In
Bandwidth Limited Networks
After having started as a pure Internet2 broadband service current latency optimized hard- and software perform well with conventional DSL networks, which allows this principle and the respective technology to be distributed even on a global scope. Supporting narrow-band networks, however, leads to significant and often unforeseen problems in terms of traffic engineering especially when additionally considering conventional Internet usage on such endpoint connections. This paper first describes these problems in a general manner, then it emphasizes the special case of video streaming and finally presents a solution, which overcomes these problems by providing an interleaved streaming scheme of low-delayed audio- and video data.
10:30. Axel Holzinger and Andreas Hildebrand: Realtime linear audio distribution over networks
IT networks are increasingly being used to not only transport data files or other best effort traffic, but also real-time audio signals or streams. This article concentrates on the distribution of linear PCM audio in production quality and gives an overview of the requirements for these networks. We show different approaches (layer 2 versus layer 3) and we present different strategies to reliably transport audio bit-perfect across a network by examining two existing media network frameworks (Ethernet AVB and RAVENNA) and discuss the advantages and disadvantages with respect to the field of application of the professional audio domain and the broadcast domain in particular.
11:00. Kevin Gross: The Future of High-Performance Media Networking
High-performance media networking represents an emerging class of network application. The future of these applications is dependent on the trajectory of technology development in the IT industry. Market factors will also play a significant role in determining their success. By examining past development in the network field, the fundamentals of network economics and the requirements of media applications, it is possible to make some predictions about the future of network technology and networked media applications.
11:30. Stefan Heinzmann, Hans Weibel: Media Clock Synchronization Based on PTP
The Precision Time Protocol (PTP) according to IEEE 1588 and its variants are increasingly being used as the basis for achieving accurate media clock distribution and synchronization in media networks. This article introduces the principles of PTP with a view towards media clock synchronization, and gives an overview of requirements for media clock distribution in a network. We show how PTP can be harnessed for reconstructing media clocks locally in each network node in such a way that those requirements can be met. We discuss different strategies for clock synthesis and distribution, their application area, and the impact on the implementation of a node. We finally discuss two existing media network frameworks (AVB and RAVENNA) which both utilize PTP for media clock synchronization, and analyze the commonalities and differences between them.
