AES67 and SMPTE Domains
Dante supports multicast audio interoperability between Dante devices and non-Dante AES67 RTP and SMPTE ST 2110-30 audio devices.
AES67 is supported in DDM and non-DDM networks. SMPTE is only supported in DDM networks.
Use Dante Controller to subscribe to and generate AES67 and SMPTE multicast flows.
Not all Dante devices support AES67 and SMPTE – check with your device manufacturer. SMPTE support requires Dante firmware v4.2.x or above.
AES67 and SMPTE support is enabled at device level, and also at domain level. Devices and domains cannot be configured for AES67 and SMPTE simultaneously.
Enabling AES67 or SMPTE for a domain does not affect the audio transport used directly between Dante-enabled devices in the domain. Audio transport directly between Dante-enabled devices is always via Dante Audio Transport Protocol, even if the audio originated from an AES67 or SMPTE device.
Enabling Support for AES67 or SMPTE
To enable AES67 or SMPTE mode, open the Domain Details page for the domain and click Advanced Settings.
AES67 mode enables audio interoperability between Dante devices in the domain and non-Dante AES67 devices.
Note: AES67 must also be enabled at device level, via the Device Details page in DDM. You can also use Dante Controller to specify an address prefix for AES67 multicast transmit flows.
Note: AES67 uses a fixed PTP V2 domain number (0), which means that AES67 can only be enabled for one domain at a time.
SMPTE mode enables audio interoperability between Dante devices in the domain and non-Dante SMPTE devices.
Note: SMPTE must also be enabled at device level, via the Device Details page in DDM.
Note: You can enable SMPTE for multiple domains. Ensure that each domain uses a different PTP V2 domain number.
Clock masters in SMPTE clock domains are decided by the protocol via automatic election. The PTP V2 Priority values can be used to determine if your SMPTE-enabled Dante devices are more likely to be elected as masters or slaves. Refer to the SMPTE standard for more information.
A variety of parameters can be specified for SMPTE mode.
PTP V1 Multicast
If all devices in the domain that are configured for unicast clocking are at Dante firmware v4.2 or above, disabling PTP V1 multicast can prevent instability in non-Dante SMPTE devices.
PTP V2 Domain Number
Can be set to any value between 0 and 127.
However, if there are any unicast clocking devices in the domain on Dante firmware v4.0.x or v4.1.x, set this to a value between 0 and 3.
See ‘About SMPTE and Unicast Clocking’ for more information.
PTP V2 Priority 1/2
The PTP V2 priorities determine which devices in a SMPTE clock domain will be automatically elected as clock master. The range extends from 0-255, with 0 being highest priority.
PTP V2 Sync Interval
The time interval between two successive PTP V2 multicast sync packets, expressed as logarithm to the base 2.
PTP V2 Announce Interval
The Time interval between two successive PTP V2 multicast announce packets, expressed as logarithm to the base 2.
PTP V2 Multicast TTL
The range over which a PTP V2 multicast packet is propagated in your network.
PTP Slave Only
Devices in the domain will not be elected as clock master.
RTP Transmit Port
The transmit port number for RTP packets.
System Packet Time
The transmit time (transmitter) of the RTP stream expressed as the number of samples of each channel in one packet.
The receive latency for SMPTE flows in the domain.
RTP Prefix V4
The IP address prefix for RTP flows.
Configuring DDM for Interoperability with Non-Dante RTP Devices
Subscribing Dante Devices to RTP Flows from Non-Dante Devices
RTP transmit flows need to be advertised on the network by the transmitting device. These advertisements provide the information required by receivers to subscribe to the flow. The flows can be advertised in a variety of ways.
Dante Controller supports RTP descriptors transmitted via SAP, and containing a range of specific values. Flows that are advertised this way will automatically appear in Dante Controller as a transmit flow.
For non-Dante devices that do not use SAP to transmit RTP descriptors, DDM must be configured to 'proxy' the descriptor via SAP so that Dante devices can subscribe to it.
To generate a SAP/SDP descriptor for these devices:
- Copy the RTP descriptor for the relevant flow into a text editor.
- To identify the descriptor, refer to the user manual for your device (or you can use a packet analyzer such as Wireshark to search for SDP descriptors).
- Ensure that the descriptor complies with the format described in Sample SDP Specification.
- In the Domain Details for the RTP domain, click Add Session.
- Paste in the SDP descriptor and click OK.
Existing sessions will present as RTP transmit flows in the relevant domain in Dante Controller.
To remove an existing session, click the Remove button next to the session name.
Subscribing Non-Dante Devices to RTP Flows from Dante Devices
For supporting Dante devices, RTP transmit flows are created in Dante Controller using the Create Multicast Flow dialog.
The transmit flow will present automatically in the non-Dante controller software if it supports SAP/SDP parsing. If not, a mechanism is required to parse the SDP descriptor from the Dante device. The configuration of non-Dante devices to receive RTP flows is specific to the device.
About SMPTE and Unicast Clocking
The default PTP V2 domain number for SMPTE is 127. Dante devices at firmware v4.0.x and 4.1.x do not support unicast clocking when the PTP V2 domain number is any value above 3.
If unicast clocking is enabled for any devices in the domain, and SMPTE mode is activated with a PTP V2 domain number above 3, DDM will display a warning pop-up. If you acknowledge the pop-up, unicast clocking will be automatically disabled for all devices in the domain, and the SMPTE settings saved as configured. Alternatively, you can cancel the pop-up, change the domain number to anything between 0 and 3, and save the SMPTE settings without affecting the unicast clocking configuration.
The diagram below illustrates an example of a routed multi-subnet domain with a mix of Dante firmware versions, and all device clocks synchronized to a non-Dante SMPTE device.
Click Customize Clocking to specify the PTP V2 priorities for the device. This overrides the PTP V2 priorities for the domain.