ABSTRACT
This chapter focusses on practical advice as well as the necessary background knowledge for audio engineers getting in contact with IP networks. The fundamentals of IT networks and their specific applications within real-time audio environments are explained, including network topologies, IP addresses and subnets. Observed practical behaviour starts making sense to the reader and errors in configurations can be fixed in short time or avoided from the beginning. Since IT networking technology was originally not designed for audio applications with its strict requirements for low latency and high phase accuracy, some particular network principles such as multicast and quality-of-service are introduced in regard to their setup for reliable audio operation. To achieve synchronous, phase-accurate operation between multiple audio devices, PTP (Precision Time Protocol) is widely used in audio networks. Its mechanisms are introduced, supplemented with a list of recommended settings applicable across all known standard and proprietary technologies. For achieving interoperability among manufacturers, the concept of stream formats is explained, the variations of combining samples and possibly multiple audio channels into one single data packet. Furthermore, standards such as AES67, SMPTE ST 2110, Milan/AVB/TSN and NMOS and their combined use with well-known proprietary technologies such as Dante are explained. Since resilience is important for audio installations, redundancy concepts using the spanning tree protocol, link aggregation and stream duplication using the standard SMPTE ST 2022-7 are described as well. The chapter is rounded off by a list of the most common errors in audio networks, supplemented by recommendations on how to avoid them.
