The 5G architecture splits the radios physically from the base stations. Synchronization in radio is primarily based on packet synchronization techniques. The 5G requirements demand strict phase synchronization requirements, especially for radio heads in clusters. This paper discusses various architectures of synchronization of RRHs. The various servo architectures demand various types of reference clock performances. The paper presents various simulation results of phase synchronization performances with various architectures with combination of physical and protocol layer timing considering the front-haul consists of transport architectures with ITU-T bases synchronization techniques.