ariable data rates, sensitive to packet data packet delay variation packet data variation variation Not compatible with CPRI CPRI compatible modes: CPRI structure agnostic and CPRI structure aware Heavy header, high Bandwidth optimized, statistical Bandwidth optimized, statistical bandwidth multiplexing benefits multiplexing Point-to-point protocol Point-to-point and point-to-multi- Point-to-point and point-to-multipoint and point and ring topology support ring topology support Proprietary in nature Vendor-defined fields for proprietary definition Open standards-based definition No L3 definition, no sup- Ethernet- or UDP/IP-based protocol Ethernet-based protocol port for Ethernet or IP For more details, please refer to CPRI specification 7.0, eCPRI specification 2.0, eCPRI Transport Network specification 1.2 and IEEE 1914.3 specification documents. Both eCPRI and RoE also recognize many of the elements in IEEE 802.1CM-2018, "Time-Sensit- ive Networking for front-haul" (see Chapter 4). As it says in the introduction to 802.1CM: This standard defines profiles that select features, options, configurations, defaults, proto- cols and procedures of bridges, stations, and LANs that are necessary to build networks that are capable of transporting front-haul streams, which are time-sensitive. Both eCPRI and the 802.1CM standard include important recommendations for the Ethernet-based front-haul network-including QoS, latency, jitter, and frame loss ratio (FLR) requirements between the RU and the DU. Additionally, a packet-based front-haul network must be designed to keep the worst-case network delay below the end-to-end latency requirements. Please refer to the eCPRI Transport Network specification 1.2, eCPRI specification v2.0, and IEEE 802.1CM stand- ards for more details on CPRI and eCPRI. In addition to eCPRI and RoE, the O-RAN Alliance is also working on front-haul specifications. The O-RAN Alliance uses the eCPRI framework and defines specifications for an open packet- based front-haul that supports a multi-vendor e