Specifications

RAVENNA ASIO & Core Audio Guide
RAVENNA ASIO & Core Audio : Introduction to RAVENNA Technology
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Basic Components
A RAVENNA system requires a carefully configured IP network, a master clock device and any number of RAVENNA
enabled I/O nodes. The master clock can be either a dedicated device or any RAVENNA node capable of serving as
a grandmaster. The preferred time domain reference is GPS. Simple streaming across a network can be achieved
without any synchronization at all but in pro audio applications tight synchronization between all devices and
streams is absolutely mandatory. While playback synchronization in most applications requires sample accuracy,
one goal for RAVENNA is to provide superior performance by offering phase-accurate synchronization as an
option thus rendering separate reference word clock distribution throughout a facility or venue redundant.
Flexibility
The system design approach allows for operation with or without centralized services for configuration / connec-
tion management. ALC NetworX recommends that basic device configuration (e.g. initial settings and setup of
audio streams) should be executed via a web interface (http). However other methods may be used in addition or
as an alternative.
Device discovery is accomplished with DNS-SD (via an mDNS or DNS service). In small networks, without DHCP /
DNS servers, the zeroconf mechanism - a fully automatic, self-configuring method - is used for auto-IP assignment
and service advertisement & discovery.
Streams available on the network are represented by SDP records with extended information (i.e. a clock domain
identifier, RTP time stamp association etc.) Clients can connect to streams via RTSP or SDP/http.
Resilience
As you would expect RAVENNA supports redundancy. Although modern network infrastructures can be config-
ured to guarantee a high level of transport security and reliable 24/7 operation for added security there is the
option of full network redundancy. Each RAVENNA device can include two independent network interfaces which
can be connected to independent physical networks. By duplicating any outgoing stream to both network links,
any destination device will receive the full stream data on both network interfaces independently. If data from one
link is corrupted, or one network link fails completely, the uncorrupted data is still present on the other link.
Changeover in the event of the failure of a network link is automatic.
RAVENNA Network Basic Components Example