Multiple RAVENNA devices - PTP Priorities recommendations – Neumann

When several RAVENNA / AES67 devices are running on the same network, a device has to be elected to PTP Master.
According to IEEE1588-2008, the PTP Master can be elected via its priority value.
To access Merging / Neumann devices PTP settings, open the device advanced pages > PTP Tab.

PTP Priority value :
1 is the highest priority, 255 the lowest one.
Merging/Neumann devices are by default using Priority 127 when set as PTP Master and 255 when PTP slave

PTP Domain : allow to define a specific PTP domain, usually when several PTP masters are required in the same network (default value for Merging devices and programs is 0).

PTP Settings:

Priority 1 is the main priority value.
Priority 2 is only used if the other parameters do not allow to elect a PTP master (if other devices on the network have the same Priority 1 for example).
Class - Delay Mech. - Announce - Sync : those values should NOT be modified
Slave only : forces the device to always be PTP slave.

Example:

To set the PTP priorities on a network :
A: Main Master priority
B: Secondary Master priority (if Main Master device fails)
C: Other devices priority

Priorities should be set as A < B < C
C should probably be 128, but as some devices may no have a manual PTP priority, it could be even lower.

Sync to external clock:

For Merging/Neumann devices, only the PTP Master device can sync to an external clock (WordClock, AES, MADI,...). The PTP clock generated by the Master will allow the PTP slave devices to be in sync with the external clock.

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