Software Architecture for a Multiple AVB Listener and Talker Scenario Christoph Kuhr and Alexander Car^ot Department of Computer Sciences and Languages, Anhalt University of Applied Sciences Lohmannstr. 23, 06366 K¨othen, Germany, fchristoph.kuhr,
[email protected] Abstract 1.2 Concept for a Realtime Processing Cloud This paper presents a design approach for an AVB network segment deploying two differ- A specialized and scalable server infrastructure ent types of AVB server for multiple paral- is required to provide the realtime streaming re- lel streams. The first type is an UDP proxy quirements of this research project. The ser- server and the second server type is a digital vice time property of an Ethernet frame arriv- signal processing server. The Linux real time ing on a serial network interface at the wide area operating system configurations are discussed, network (WAN) side of this server cloud, is of as well as the software architecture itself and paramount importance for the software design. the integration of the Jack audio server. A During the service time of a single UDP stream proper operation of the JACK server, along- datagram, no concurrent stream datagrams can side two JACK clients, in this multiprocess- be received. Thus, the latencies of all streams ing environment could be shown, although a arriving on such an interface are accumulated. persisting buffer leak prevents significant jitter In addition to connecting the 60 streams to and latency measurements. A coarse assessment each other, the Soundjack cloud provides dig- shows however, that the operations are within ital signal processing algorithms for audio and reasonable bounds.