Dante is a network solution built on standard network protocols and designed to work over a Local Area Network.
If you are planning on deploying Dante over longer Distances, there are some things regarding the network topology that will need to be considered. These are:
Network Routing design
- The distant locations might be part of the same VLAN or be on different routed Network Subnets.
- If the distant locations are on different routed subnets, the use of Dante Domain Manager (DDM) will be mandatory.
Network Propagation Time (Latency)
This is the average time it takes for the packets to get from location A to location B on the network.
- Network Latency is going to be compensated by the Dante devices thanks to the Device Latency setting:
- Under “Unmanaged” Dante Networks the maximum available Latency is 5ms for Hardware Dante devices and 10ms for Software implementations (like DVS or VIA)
- Under DDM managed networks the maximum latency can be increased to 20ms or 40ms on Hardware Dante devices only depending on the Dante implementation they are using.
Network Jitter
- This is time delta variance for network packets traveling between the locations.
- This is going to have a direct impact on the Dante clocking mechanism which is PTP based.
- If the jitter is too high, the Dante devices will lose sync and mute. This can be the case over encrypted VPN links or locations connected with intermediate firewalls.
- Dante Hardware implementations will have jitter tolerances up to around 250us.- Dante Software implementations are more tolerant and can go up to 1ms of jitter. This is mainly due to some OS not supporting PTP Hardware Time-stamping.
- Jitter on the network can be improved by the implementation of QoS but it might not be sufficient in some cases.
- We recommend using PTPv2 capable GPS clocks on the different locations to break the clocking dependency between sites. DDM will be required for creating multiple Clocking Zones over the different locations Subnets.
Packet Loss
- Dante assumes that there are no packet loss on the network (which is usually the case over a LAN) and has no recovery mechanisms to cope against this.
- This will result in audio artefacts because of Audio Sample loss.
- Links over the Public Internet are inherently prone to packet loss.
Our general recommendation is to use dark fibre or Private Links between the different locations in order to have control over the parameters described above.
Locations linked using VPN over the Public Internet will likely fail to achieve Dante Over Distance.