A Sample-Mode Packet Delay Variation Filter for IEEE 1588 Synchronization

Recent studies have shown that the delay distribution of IEEE 1588 synchronization traffic varies with the characteristics and amount of the background traffic in the network, and influences the choice of packet selection filters. In this paper, we characterize the delay profile of an Ethernet cross-traffic network statically loaded with one of the ITU-T network models and a larger Ethernet inline traffic loaded with uniformly-sized packets. We also propose an iterative sample-mode packet delay variation (PDV) filter and use numerical simulations in OPNET to illustrate the performance of the filter in the networks. We compare the performance of the proposed PDV filter with those of the existing sample minimum, mean, and maximum filters and observe that the sample-mode filtering algorithm is able to match or outperform other types of filters, at different levels of network load.