A list of issues regarding White Rabbit Specification v2.0
- Invalid timestamps
-
Description: When master (i.e. WR switch working as
Grandmaster) is adjusting it's clock the timestamps of Sync
Messages are invalid. If used (the timestamps) by the slave
(i.e. WR switch or WR Node), the synchronization is improper
-
Current solution: If a timestamp is invalid, the Follow_UP
message is not sent. Instead, the Sync Message is re-sent.
- Autoconfiguration of WR Network using BMC
-
Description: We want to precisely control the configuration
of a WRPTP network so that a misbehaving device (i.e.: WR node,
WR switch) will not break the timing hierarchy of a system. This
means that some ports of a boundary clock (i.e. WR Switch) shall
never become master ports, while the other will never become
slaves. In PTP, it is only possible to set slave-only mode in an
ordinary clock.
-
Current solution: Each port has a configuration flag
(WR_SLAVE_ONLY, WR_MASTER_ONLY and WR_MASTER_AND_SLAVE).
This flag restricts (in WRSpec.v2.0) WRPTP protocol only, so a
port with configuration WR_SLAVE_ONLY will never become WR
Slave but can become "standard PTP slave". Now, the WR_* flag
affect also functioning of PTP and the modifiedBMC is used only
if WR_MASTER_AND_SLAVE flag is set for a port. Otherwise, the
modified BMC is skipped