Achieving Constant Delay in 1588 Aware Switching Devices
Publication Date: 2016-Oct-31
The IP.com Prior Art Database
Achieving constant delay/fixed latency in network elements is an important feature of timing sensitive networks. This disclosure describes how system timers can be utilized to guarantee fixed latency in 1588 devices. By including the ingress timestamp in frames to the very boundary of the egress MAC, and knowing the maximum delay for uncongested traffic through the switching core, frame transmission can be suspended until the maximum delay is reached. The graph below illustrates the effect. Orange curve shows the delay variations without enabling the "Fixed Latency" functionality. Green curve shows the packet latency with "Fixed Latency" enabled.