Cirrus Logic Bundle Assignments in CobraNet Systems User Manual

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Some devices only accept 8 audio inputs, while others accept 16 or 32. Obviously if a device
accepts 16 audio inputs and can only transmit 2 Bundles, It cannot use this technique.

Also be aware that different CobraNet

devices can receive different numbers of Bundles, and select only

certain audio channels from those Bundles to use or output.

We suggest using the following procedure in designing a CobraNet

network.

• Make a list of all the audio sources and their locations.

• For each source, list the destination(s) it needs to go to.

• Group the audio sources at a location into Bundles with no more than 8 audio channels in a given

Bundle (or 7 if 24 bit).

• Determine if each Bundle can be unicast, or if it must be multicast.

• Make sure you don’t have more than 4 Multicast Bundles on a network. If you need more than 4

Multicast Bundles:

o Consider using multiple switched networks or VLANs
o Consider transmitting several Unicast Bundles instead of one Multicast Bundle.

• Use the following rules to see if you can send more than 4 multicast Bundles on a given network

or VLAN:

o Carefully map the number of Bundles sent to each port of the system. The total of

multicast and unicast Bundles arriving at each switch port may not exceed 8.

o If a half-duplex device that can only transmit 2 Bundles, and is set to transmit using both

its Bundles is part of the network, then you must make sure that the network conductor is
not transmitting a multicast Bundle. This may require changing the default conductor
priority of one or more devices in the system to assure this condition is met.

• Map the Bundles carried by every link in the system to make sure that the limit of 8 Bundles each

direction on a given Fast Ethernet connection is not exceeded.

If more than this number is needed for uplinks between switches, then one solution is to use managed
switches which can support trunking. Trunking allows more than one Ethernet link to be used to carry the
traffic between switches. Another solution is to use switches supporting Gigabit Ethernet uplinks. These
provide ten times the bandwidth of a Fast Ethernet uplink.

This entire document was based on the use of full Bundles. If Bundles containing less than the maximum
number of audio channels are used, it is possible in some cases to exceed the limit of 8 Bundles on Fast
Ethernet.