 (CPRI partitioning or "Option 8"): This is equipment that follows classic functional split, aka "Option 8" in 5G/NR language. The FFT/CP functionality is located at the REC (DU) location and baseband I/Q samples are transferred to the RE (RU). The RE and REC are connected by a bridged Ethernet network. Traffic is split over three categories following CPRI terminology: IQ data (samples) IQ data is exchanged regardless of whether end-user data is exchanged (i.e., also when the radio is technically idle) and can be represented as constant bit rate flow. Latency is defined as <100 us end-to-end REC < - > RE, including propagation delay and network internal bridge delay. Frame Loss Ratio (FLR) must be bounded to <10-7. Control and Management (C&M) (exchanged between control and management entities on REC/RE) There is no explicit latency requirement for this traffic. FLR must be bounded to <10-7. Synchronization (frequency as well as time/phase) is done using existing solutions and protocols. Synchronization can be done using PTP (IEEE1588), SynchE, GNSS (GPS,) or other (proprietary) methods. Class 2 (eCPRI partitioning or "Option 7"): This is equipment that follows eCPRI split options and as such a flexible split functional split of the 3GPP Physical Layer between REC and RE. Traffic is split over three categories following CPRI terminology: IQ data (no longer necessarily samples), with subcategories User data. Latency is defined as <100 us end-to-end eREC < - > eRE. FLR must be bounded to <10-7. Real-time control data, associated directly with user data. Data for other CPRI services (UP support, remote reset, ...). Control and Management (C&M) C&M information is exchanged over commonly used transport protocols such as UDP and TCP. There is no specific eCPRI protocol. Synchronization Synchronization (frequency as well as time/phase) is done using existing solutions and protocols as outlined for class 1. Chapter 2 System components, requirements, and interfaces 93 Timing and frequency synchronization requirements are 