Connecting UMTS/GSM base stations over Metropolitan Gigabit Ethernets has a great potential of cost savings. However, packetizing base stations ’ signals to emulate telephone circuits over Gigabit Ethernets additionally requires synchronization between the sending and receiving circuit emulation adapter. In this paper, we present and evaluate open source implementations of synchronization algorithms that are based on the concept of estimating the minimal end-to-end delay from sender and receiver time stamps. We show that such implementations meet the ITU-T G.823 requirements for synchronization and generally outperform the synchronization algorithms employed in commercially available circuit emulation adapters.