<p>The present invention provides a method for synchronization including: a Synchronous Digital Hierarchy (SDH) device as the slave clock exchanges a Precision Time Protocol (PTP) message utilizing idle bytes in the section overhead of SDH frames with another SDH device as the master clock, calculates the time offset to the SDH device as the master clock, and adjusts the SDH device as the slave clock with the time offset, in order to realize precise time synchronization between SDH devices. The present invention also provides a system for synchronization.</p>
