Multicast with Dante controller can be used, when should I use it?
If multicast is used, we recommend that IGMP snooping is enabled.It's important to use a minimum amount of multicast.Most small-to-mid scale Dante systems can be configured with unicast by default.To understand when the settings of a switch need to be configured, it's first necessary to understand "flows".
Two audio signal transmission methods can be used in a Dante network.Unicast is a method in which signals are transferred from one device to another.In multicast, signals are transferred to multiple devices within the network.All audio transmission within a Dante network is unicast, and there is usually no need to change this setting.Let's look at which method is better for sending the same audio signal from one device to several other devices.
packets are duplicated for each device that the signal is sent toYou don't have to consider whether the signals are duplicate of each other to set the route.We recommend that you use unicast under normal circumstances because it results in low switch loads and makes configuration easier.
A single packet is split by the switch and delivered to multiple devices.Because the switch has to duplicate the packets for each port and transmit them to each device, multicast results in increased switch loads.Multicast results in the transmission of packets to ports that don't need them.The Internet Group Management Protocol can be used to prevent this transmission.Each device sends IGMP messages to report which addresses they need.The switch remembers which ports are connected to devices that have registered for a specific address and filters the traffic accordingly.The function is referred to as IGMP snooping.If you don't enable IGMP snooping on the switch, multicast packets will be duplicated and transferred to each port.The switch may need time to determine which ports are connected to which devices before IGMP snooping can form the intended multicast groups.Multicast is a special setting that can only be configured from the Dante Controller software and that increases the workload of the switch.
In most cases, the audio data that travels through a cable will not exceed 512 channels, so in normal circumstances, unicast is the best choice.When is multicast absolutely necessary?It's when a transmitter goes out.
Flows are created automatically when Dante is configured.The units of transmission are called flows.Before being transmitted, multiple channels are grouped together.Up to four channels of audio data can be contained in Unicast flows.packets that are big enough for four channels will be sent to the receiver if channel 1 is assigned to a specific receiver.Because the use of flows with open channels is prioritized, no new flows will be created until all four channels in the most recently created flow are filled.
There are limits to the number of flows that can be assigned.The R Series I/O rack can send and receive 32 flows.The Rio3224-D, which has 32 analog inputs, can send all 32 channels to a single Dante device.The unicast flows have to be used in order to send the channels to 4 devices.
The maximum number of channels that can be sent is 32, but because the flows assigned to each Dante device contain four channels, the more flows there are that don't use all four.multicast is needed to reduce the number of transmitted flows if a transmitter runs out.The number of transmitted flows can be checked using the Dante Controller software.If there aren't enough available flows, a notification will appear.When single channels are received from a large number of devices, it is possible for the receiver to not have enough flows.multicast will not reduce the number of flows, so it is necessary to reconsider the route.
If there aren't enough flows available for transmission, you can use the Dante controller software to reconfigure the network so that less flows are used.Do not use the routing functions that can be configured from specific Dante devices and software if you can only use Dante Controller.multicast flows increase the load that the switch is subjected to, so be careful to keep the number of channels to the minimum.Up to eight channels can be grouped into a flow.
When multicast is necessary, the following procedures should be performed to set IGMP snooping and related settings.
Next to Bridge Multicast Filtering Status, there is a check box labeled "Enable".In this example, we are assuming that Dante 2 is for the network within which multicasting will be used.
Next, in the following page, select the "Enable" check box and then click "Apply".To change the IGMP snooping settings, you must select the VLAN ID for the network within which the multicast will be used.
There are check boxes next to IGMP Querier Status.You should set the query interval to 30 seconds and the IGMP Querier version to "IGMP V3".The time required before multicast starts working is longer when the query interval is large.All switches in the network should run the same version of IGMP V2 and V3.If the network includes switches that only support IGMP V2, be sure to select "IGMP v2 as the I GMP quirier version"
If you are going to use multiple switches to multicast, you will need to set up multicast router ports.These ports will be used to send multicasts and IGMP messages.multicast packets may be sent between switches and some may fail to be delivered if the port is not configured.The preset recall of different systems will not be linked.No special port settings are required with the above settings because auto learning has been enabled.If you are using another switch, you need to know the port that connects it to the multicast port.
The network should only have one IGMP equerier.Multiple IGMP messages will end up being sent if Multicast works.One of the switches in the network will become the querier, so no special settings are required.If there are switches in the network that have different settings, make sure to set them up so that there is only one.
We recommend that you register the multicast address used for detecting devices if you have access to the Dante network.It is possible that IGMP messages will not be properly transferred when the network is accessed over the internet.Devices will not be detected through the access point if IGMP snooping is malfunctioning.You should register the corresponding multicast address in order to detect devices reliably.To apply the setting only to the switches that access points will be connected to, follow the procedure below.
There is a page where you can register a multicast address.To open a dialog box, click "add"In this example, we are assuming that VLAN 2 is for Dante, so we need to set the IP Multicast Group Address to "224.0.0.251".
The registered multicast address should be assigned to the corresponding ports.Click "Details" to open a dialog box after selecting the address that you registered.Click "Apply" if you want to set the corresponding ports to "Static".
The settings for the switch are complete.You should save the settings after you change them.