Describes how PTP protocol synchronizes clocks over DLR networks using optimized grandmaster election and fault detection mechanisms.
PTP is a protocol used to synchronize clocks between networked devices with sub-microsecond accuracy. The best master clock algorithm (BMCA) elects a grandmaster clock (GM), which serves as the synchronization source for all other clocks in the network. However, the BMCA process can take several seconds. This delay may cause issues during a DLR ring fault and recovery.
Summary
The key components involved in how PTP over DLR works are:
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PTP protocol: Synchronizes clocks between networked devices to sub-microsecond accuracy using the best master clock algorithm.
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Grandmaster clock (GM): Serves as the synchronization source for all other clocks in the network.
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DLR network: Provides rapid link fault detection and isolation using redundant ring topology.
Workflow
These stages describe how PTP takes additional cautions to work and converge over a DLR network:
- GM election: The GM election process is optimized to reduce the time it takes to reconverge. This is achieved by using a combination of DLR fast link failure detection and DLR ring fault or recovery events to trigger reconvergence on all switches of the DLR ring simultaneously.
- Fault Detection and Isolation: DLR provides rapid link fault detection and isolation by using a redundant ring topology. When a link fails, the DLR ring automatically reconfigures to maintain connectivity. PTP takes advantage of this feature and ensures that it does not trigger a reconvergence on PTP end devices.