Image Number 2 for United States Patent #6665316.
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.