System Management
7210 SAS M, T, X, R6 Basic System Configuration Guide Page 231
two-step synchronization operation can be used, with the two-step operation requiring a follow-up 
message after each synchronization message.
NOTE: The 7210 SAS-M and 7210 SAS-X supports only two-step operation. 7210 SAS-T 
supports one-step operation by default and can interoperate with devices supporting two-step 
operation.
During startup, the PTP slave clock receives the synchronization messages from the PTP master 
clock before a network delay calculation is made. Prior to any delay calculation, the delay is 
assumed to be zero. A drift compensation is activated after a number of synchronization message 
intervals occur. The expected interval between the reception of synchronization messages is user-
configurable.
The basic synchronization timing computation between the PTP slave clock and PTP best master 
is illustrated in Figure 18. This figure illustrates the offset of the slave clock referenced to the best 
master signal during startup.