The
WR Technology
White Rabbit provides sub-nanosecond accuracy and picoseconds precision of synchronization for large distributed systems in which devices are interconnected in a network.
White Rabbit (WR) Technology consists of a set of open-source basic blocks that can be used to implement WR Switches and WR Nodes. When interconnected, WR Switches and WR Nodes create a WR network. Such a network is a PTP-enabled Bridge Local Area Network compatible with IEEE 802.1Q, IEEE 802.3 and IEEE 1588 standards. WR Technology implements both the WR Protocol and the PTP-HA profile. The sub-nanosecond synchronization is provided only between WR Switches and WR Nodes.
Modifications and Extensions
The aim of the Collaboration is to ensure that the WR Technology is well supported. It is often the case that WR applications need both modifications of WR Technology and extensions which may lie outside WR Technology. The Collaboration can be used as a forum to debate what should be the interfaces of the WR Technology to the extensions (which could be open-source or proprietary) and what should be the modifications (which should be open-source) to the WR Technology. Bringing about a good equilibrium that combines a solid set of open-source building blocks with the freedom to perform proprietary customisations when needed, is important for the Collaboration. In time, some of the open-source extensions can become modifications, i.e. the WR Technology can grow in scope to encompass domains previously covered only through extensions.
WR Technology Licence Conditions
The open-source hardware, gateware, firmware, software and documentation of the WR Technology are intended to be licensed under permissive and weakly-reciprocal licences. Therefore, customising a WR Switch or a WR Node by extending its functionality with open-source or proprietary features are possible.
The weakly-reciprocal licenses used in the WR Technology:
– Hardware: CERN-OHL-W-2.0+
– Gateware: CERN-OHL-W-2.0+
– Firmware: LGPL-2.1-or-later
– Software: LGPL-2.1-or-later
– Documentation: CC-BY-SA-4.0+