Attero Tech Box 4 I/OP - Manual (Page 22)

VoiceBox 4 I/OP
User Manual
 Attero Tech LLC 2010 Page A-1 614-00008-02
APPENDIX A – Introduction to CobraNet
CobraNet is an audio networking technology for delivery and distribution of real-time, high quality, uncompressed digital
audio using a standard Ethernet network. It is implemented using a combination of hardware, firmware, and the CobraNet
protocol.
Unlike other audio networking or distribution technologies, CobraNet is a true network and exists on standard Ethernet
networks using standard Ethernet hardware. Since it is a true network, audio routing is highly flexible between network
nodes and can be used in a variety of audio distribution applications.
In addition to the high degree of routing flexibility that CobraNet provides, the technology also incorporates the ability to
monitor and control CobraNet devices remotely. This is a key feature that is highly important in fixed installation
applications where the audio distribution equipment may not be readily accessible. All CobraNet devices on the network
can be controlled and monitored from a central location by sending control commands and monitoring device specific
parameters.
CobraNet provides this capability by implementing Simple Network Management Protocol (SNMP). SNMP is a standard
protocol typically used for monitoring network devices such as Ethernet switches. In the case of CobraNet, it allows users to
communicate with any CobraNet device using standard SNMP tools or a customized user interface designed specifically for
CobraNet, such as Attero Tech’s Control Center application.
The figure above represents the types of data that coexist on a CobraNet network.
Before a CobraNet system can be configured, it is important to first understand how CobraNet distributes audio between
devices.
Audio is sent in "bundles" on a CobraNet system. Each bundle is capable of holding up to 8 logical audio channels. Every
CobraNet device has a number of bundle transmitters and bundle receivers. These transmitters and receivers are the
mechanism used to send and receive bundles between devices.
For a transmitted bundle, audio may be sourced either directly from the local audio inputs of the device or from internal
audio via the on-board DSP
1 , but not both simultaneously. Internal audio from the onboard DSP could have originally been
sourced from the local device inputs, sent from another CobraNet device or even generated by the DSP itself. Combinations
of the local or internal audio may exist within a bundle in any order. Additionally, a single audio source in a device may be
used multiple times in a single transmitter bundle or across multiple transmitter bundles.
For a received bundle, the received network audio may be routed directly to the device’s local outputs, the internal DSP 1 or
simply ignored.
Once the contents of a bundle have been decided, the next step is to pass the bundle to another CobraNet device. To do
this, every CobraNet device has up to 4 bundle transmitters. Each bundle transmitter has a transmit mode that must first be
selected. This affects how many devices may receive that particular bundle at a time.
1 Not available on all devices – CS496xxx devices only