Awareness | Quality of Service settings across QLAN, Dante, and AES67
Learn how to make sure your networked audio systems proper Quality of Service (QoS) settings for QLAN, Dante, and AES67.
Information
Q-LAN, Dante, and AES67 audio transports all use DSCP markings to show the importance of time-sensitive packets on the network. The Ethernet infrastructure is then in turn configured to prioritize packets with the desired markings above others.
The markings associated with each protocol are as follows (highest to lowest priority, top to bottom):
| Audinate Dante | Audinate AES67 | "Standard" AES67 | Q-LAN Audio/Video | |
|---|---|---|---|---|
| PTPv1 | 56 | |||
| PTPv2 | NA | 56 | 46 | 46 |
| Audio | 46 | 46 | 34 | 34 |
| 'Other' PTPv1 | 08 | |||
| Video | 26 |
Note that Audinate-based implementations use DSCP marking 46 for audio packets while 'standard' AES67 implementations and Q-LAN use DSCP 46 for PTPv2. We would like to avoid this priority conflict on the network where possible.
This would require at least one of the following:
If there are a mixture of Audinate devices with 'standard' AES67 implementation (such as AtteroTech AES67 units)
- Place Dante and Dante-based AES67 devices on separate physical networks (from Q-LAN and 'standard' AES67).
- 'Standard' AES67 devices could be placed on the Q-LAN network (as they carry the same DSCP markings).
OR
- Configure the network switch to prioritize sensitive traffic using Access Control Lists (ACLs) and Policy Maps, avoiding DSCP marking. For instance, since PTPv1 and PTPv2 both utilize the multicast destination address of 224.0.1.129 and UDP ports 319/320, it’s possible to classify PTP traffic by these parameters. This approach, while demanding a deep understanding of networking and the addresses/ports each AV protocol utilizes, enables the successful integration of various traffic types on a single network. Consultation with a Network Engineer is advised.
- Note this approach typically requires an Ethernet switch with more complex features, thus more expensive than simpler models.
If the network consist of ONLY Audinate-based devices and Q-SYS (Q-LAN)
- Q-SYS Designer allows the user to change the DSCP markings of Q-LAN to match the Audinate DSCP values in the "Design Properties" dialog. Choose the "Audinate" QoS Preset in this case
- With Q-LAN using the same markings as Audinate devices, now the Ethernet network can be set up according to Audinate's recommendations.