US 12,429,903 B2
System and method to determine sets of untraceable clock domains
Manik Singhal, Bengaluru (IN); and Parthibhan Paramaguru, Bengaluru (IN)
Assigned to CISCO TECHNOLOGY, INC., San Jose, CA (US)
Filed by Cisco Technology Inc., San Jose, CA (US)
Filed on Dec. 20, 2023, as Appl. No. 18/390,127.
Prior Publication US 2025/0208646 A1, Jun. 26, 2025
Int. Cl. G06F 1/12 (2006.01); G06F 1/14 (2006.01)
CPC G06F 1/12 (2013.01) [G06F 1/14 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An apparatus, comprising:
a memory configured to store:
a plurality of clock source selection operations configured to enable selection of one or more clock sources; and
a plurality of clock monitoring operations configured to monitor the plurality of clock source selection operations; and
a processor communicatively coupled to the memory and configured to:
receive a first clock and a second clock from a first network device;
receive a third clock and a fourth clock from a second network device;
select the first clock as a Precision Time Protocol (PTP) clock;
select the second clock as a Synchronous Ethernet (SyncE) clock;
calculate a first time drift associated with the third clock;
average the first time drift over a first plurality of successive PTP timestamps;
determine whether a first average of the first time drift over the first plurality of successive PTP timestamps is higher than a threshold;
in response to determining that the first average of the first time drift over the first plurality of successive PTP timestamps is higher than the threshold, generate a first report indicating that the third clock of the second network device is offset with respect to the PTP clock; and
in response to determining that the first average of the first time drift over the first plurality of successive PTP timestamps is less than or equal to the threshold, generate the first report indicating that the third clock of the second network device is not offset with respect to the PTP clock.