The Model 5401A Dante Leader Clock and the Model 5402 Dante Leader Clock with GNSS Synchronization were primarily designed for use in applications that utilize devices running “native” Dante. To support the timing needs of these devices Precision Time Protocol Version 1 (IEEE-1588-2002 or “PTP v1”) was implemented. The units’ PTP v1 implementation functions very well, including in redundant Dante applications. (Independent Ethernet networks connected to the Primary and Secondary Ethernet ports on the back panel of the Model 5401A and Model 5402 units.) Even in large installations with literally hundreds of Dante devices, correct performance has been confirmed.
However, the Model 5401A and Model 5402 are more limited in their ability to support applications that require Precision Time Protocol Version 2 (IEEE-1588-2008 or “PTP v2”). This includes support for AES67 and ST 2110 devices. A significant Model 5401A and Model 5402 PTP v2 limitation is because Studio Technologies, within the units’ firmware (embedded software), does not have the ability to revise any of the PTP v2 operating parameters. This greatly restricts the ability to use a Model 5401A or a Model 5402 as a general-purpose PTP v2 time server. (This type of device was previously known as a PTP “grandmaster” device.) For example, SMPTE® ST 2110-10 specifies that compliant devices must utilize the SMPTE ST 2059-2 standard for their timing reference. An associated set of PTP v2 parameters (denoted as the “SMPTE profile”) is detailed in the technical standard for ST 2059-2. Unfortunately, the Model 5401A and Model 5402 do not allow selection of a specific profile. The units have to follow the configuration originally established by Audinate (developers of Dante) for supporting AES67 devices.
These PTP v2 parameters are “fixed” within the Model 5401A and Model 5402 and cannot be revised by the user:
Domain 0
Priority 1:
114 (Dante Preferred Leader enabled, Sync to External enabled)
119 (Dante Preferred Leader enabled, Sync to External disabled)
242 (Dante Preferred Leader disabled, Sync to External enabled)
247 (Dante Preferred Leader disabled, Sync to External disabled)
Clock Class: 248
Accuracy: Unknown (0xFE)
Variance: 61536
Priority 2:
112 (Dante Preferred Leader enabled, Sync to External enabled)
112 (Dante Preferred Leader enabled, Sync to External disabled)
116 (Dante Preferred Leader disabled, Sync to External enabled)
116 (Dante Preferred Leader disabled, Sync to External disabled)
Unique ID: 00:1D:C1:XX:XX:XX
DSCP: ER (46)
While this limitation can be an issue, on the positive side, as with PTP v1, independent PTP v2 performance will be provided on the Primary and Secondary Ethernet ports of the Model 5401A and Model 5402 units. So redundant or “dual stream” performance should be possible.
In conclusion, the Model 5401A Dante Leader Clock and the Model 5402 Dante Leader Clock with GNSS Synchronization can be very effective products for the appropriate applications. But neither is intended to serve as a general-purpose PTP v2 time server. Will they work in many cases? Absolutely. But careful testing is required to ensure that the desired PTP v2 performance will be provided. Please refer to the specific Model 5401A or Model 5402 user guides for details on this topic.
Model 5401A Dante Leader Clock (top) and Model 5402 Dante Leader Clock with GNSS Synchronization