ClearOne Dante Controller User Manual

Page 65

Dante Controller User Guide

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The window shows a list of the Tx channels for the device, and allows you to add them to the new
multicast flow that is being created, by checking the tick box next to each channel name. Once you have
selected all the channels required, create the multicast flow by clicking the Create button at the bottom of
the dialog box. To abandon creating a new multicast flow, click Cancel.

A single multicast flow can contain up to the maximum supported channels per flow for this device. This is
displayed at the top of this window, and is 8 channels for this device. If you select more than the maximum
allowed channels per flow, multiple flows will be created.

Once a flow has been created, it will appear in the list of flows in the transmit pane, along with the channels
contained within that flow. Channels cannot be added to or removed from existing flows. Each time the
dialog is used to select additional channels, a new multicast flow will be created.

By default, Dante devices 'prefer' multicast over unicast. When you click a transmit channel to make a
subscription, the receiver will automatically connect to the channel via a multicast flow, if one exists.
Likewise, when a channel that did not form part of an existing multicast flow is added to a new multicast
flow, any existing unicast subscriptions to that channel will automatically switch over to use the new
multicast flow.

Care should be taken when deleting a multicast flow, as the existing subscriptions will convert back to
unicast. This has the potential to result in exceeding the link capacity or maximum number of flows at the
transmit device, as multiple unicast flows will be established between the transmitter and its receivers. It
may be advisable to remove some or all of the audio routes prior to deleting the multicast flow.

A good rule of thumb is to use multicast when there are more than two receivers for a specific audio
channel. You should also assume that the flow will flood throughout the entire network, and therefore
consume bandwidth on all network links.

Note: Certain Ethernet switches support IGMP (Internet Group Management Protocol), a protocol
that provides the ability to 'prune' multicast traffic, so that it travels only to those end destinations that
require that traffic. If this is the case, and IGMP is correctly configured on all the Ethernet switches,
then multicast audio will not flood throughout the network, but will instead be sent only over the links
required to deliver it to subscribed devices.