Open RAN is an eCPRI-based open fronthaul interface between the radio unit (RU) and distributed unit (DU). This white paper discusses timing accuracy for eCPRI fronthaul transport networks. Renesas time synchronization hardware and software products meet the tight time error requirements of eCPRI and Open RAN equipment. The product line includes system synchronizers for DUs, switches and routers used in fronthaul networks, and radio synchronizers for RUs. Linux oriented PTP software is available for both families of synchronizer products.