US 6,665,316 B1 · Organization of time synchronization in a distributed system

Abstract

A distributed system with mechanisms for automatic selection of master and slave clocks to be used for clock synchronization. The distributed system includes a set of nodes, including a first node and a second node, each having a local clock and a set of information pertaining to the local clock. The first node transfers a packet on a communication link that carries the information. The second node receives the packet on the communication link and determines whether the local clock of the second node is a master clock that synchronizes a time value in the local clock of the first node or a slave clock that synchronizes to a time value from the local clock in the first node by comparing the information in the packet to the information pertaining to the local clock in the second node. Automatic selection of master and slave clocks in boundary nodes is provided along with mechanisms for determining clock synchronization delays and mechanisms for reporting jitter associated with communication devices.

Claims15

Dependent claims

A distributed system, comprising:

a set of nodes coupled to a communication link, each node having a corresponding local clock for maintaining a corresponding local time value and storing a set of local clock information, each node initially assuming a role of master clock by transferring a corresponding timing data packet on the communication link that carries the local clock information;
each node when in the role of master clock determining a best master clock in response to a received timing data packet by comparing the local clock information from the received timing data packet to the corresponding stored local clock information using a prioritized set of rules including a rule pertaining to whether the local clock information indicates a standard time value, each node assuming a role of slave clock if best master clock is not the local clock such that each node in the role of slave clock synchronizes the corresponding local time value to a time value from the best master clock.

Dependencies are inferred from the claim text.

Organization of time synchronization in a distributed system

Life of this patent

Organization of time synchronization in a distributed system

Life of this patent

Abstract

Claims15