Precise time protocol in Ethernet over SDH network

This article deals with transmission of Precision Time Protocol (PTP) over SDH (Synchronous Digital Hierarchy) network. Precision Time Protocol described in standard IEEE 1588 - Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems - is a protocol for synchronization in packet networks. This article discusses the transmission of Ethernet synchronization messages over existing SDH networks. The introduction in this paper provides possibilities of synchronization in telecommunication networks and packet networks. Synchronous Ethernet and Precision Time Protocol are methods for synchronization in packet network. The second part of this article describes several measurements and comparisons of the accuracy of precision time distribution for different conditions in Ethernet over SDH network. These results are also commented here and several conclusions about the influence of transmission capacity are given in this article.