QSC Audio S series - Manual (Page 27)

27
When a switch is shared with non-CobraNet data, it
should be configured so that CobraNet audio is isolated
from conventional data communications. Partitioning is
usually accomplished by enabling multiple VLANs. Co-
braNet data should be given the highest network prior-
ity in order to prevent the loss of audio. LAN, node, port
and data or packet type prioritization can be defined
through switch management software, industry proto-
cols - such as Request For Comments (RFCs) supporting
Quality of Service (QoS) - and through network design.
Information on VLANs, QoS and network protocol sup-
port is available on the Peak Audio website and from a
host of switch manufacturers.
• Try to assign unicast bundles between RAVE devices
when operating on network switches. This provides
point-to-point communications, which conserves band-
width and prevents port flooding. As a rule of thumb,
CobraNet supports up to four multicast bundles per
broadcast domain or LAN. Audio delivery may be unreli-
able beyond this limit. If the benefit of switches is needed
and the requirement exists for multiple receivers for a
given bundle, it may be necessary to partition the net-
work into smaller LANs. This results in multiple inde-
pendent CobraNet networks on the same switch hard-
ware, each LAN with its own “conductor”. Each LAN can
then support up to four multicast bundles.
Conductor priority may also be a concern on network
switches when implementing multicast traffic. The RAVE
160s-24 and 80s are currently assigned the highest “con-
ductor” priority. Since these units have the least amount
of transmission requirement, they are the best candidates
for handling the “conductor” role. A transmitter with two
outgoing bundles, such as the RAVE 161s-24, may be
overly burdened if it is required to act as “conductor”,
transmit both its bundles, receive unintended multicast
Network Design Considerations:
Switched Networks (continued)
bundles and possibly service SNMP messages. The de-
vice defaults should handle these conditions appropri-
ately. However, some configurations may require alter-
ing the “conductor” priority of some devices through the
Management Interface.
• RAVE supports both stand-alone and software configu-
ration. The default mode for RAVE is hardware control.
In this mode, the bundle assignments are set through
the front panel hexadecimal switches. These switches
provide a subset of the available CobraNet bundle as-
signments. These switches also provide access to some
configuration settings such as “external synchronization”,
“software kill”, “serial programming” and selection be-
tween “unicast” and “multicast” addressing. You can
quickly design a RAVE network right out of the box by
simple configuration via the front panel switches.
In software mode, a RAVE is configured through the
management interface using SNMP. With the MI, you
can have access to additional bundle routing, complex
internal audio mapping, audio channel duplication, “con-
ductor” prioritization and more. Generally, a device is
configured via SNMP application software and then the
RAVE is placed into “write” mode so that all settings are
written into permanent memory. The RAVE can then be
moved or power-cycled without the loss of its configura-
tion.
Also in software mode, the front panel switches are used
to provide a unique network name for each RAVE. This
name can be seen in the “sysName” variable within
SNMP. Setting the front panel switches to “FFFF”, and
power-cycling the unit, brings the RAVE out of software
control. This “software kill” feature provides a means to
return a RAVE to stand-alone control in the event a man-
agement console or application software is unavailable.