In 5G networks, an optical fronthaul transports massive user data from remote radio heads (RRH) to the core network (CO) with high throughput and low latency. eCPRI is a new standard interface for the Ethernet-based optical fronthaul network to enhance the efficiency and performance. If fronthaul networks are deployed in an unsafe domain, an end-to-end security system should be implemented over the data flow, which usually requires additional overhead and processing time. This redundancy may cause unexpected latency and performance degradation in the data transport for 5G networks. According to the specification of eCPRI, vendors may optionally implement either IPsec or MACsec to ensure the security of transmission. In this paper, we investigate security solutions suitable for the Ethernet-based optical fronthaul network. We analyze the standard security protocols such as IPsec and MACsec for the security of the high speed link. We propose WireGuard as an alternative security solution which may replace IPsec. According to our analysis, the extended overhead for security protocols has negligible impact on the latency. However, eCPRI processing time can be prolonged, which may cause additional latency and eventually affect the maximum transmission distance of fronthaul networks. As an example, we performed a simulation of eCPRI traffic and measured the latency of WireGuard. We also point out that a re-key interval should be carefully chosen not to compromise the security of the high capacity link such as 5G fronthaul networks. Our analysis is further extended to a long-term security solution which is resistant to quantum attacks.

We assess the performance of two distinct functional splits based on latency/latency variation and mapping efficiency, both individually and in unison. By considering hardware-offloading possibilities for a low-layer split (especially a pre-resource mapper split) using an option-6 software-based local thermal equilibrium split as an example, we show how data rate, Ethernet frame size and, in general, traffic generation characteristics will be very important aspects in the design of the future Ethernet mapping function. Then, an integrated Ethernet fronthaul with legacy and new/evolved split functionality operating at 100 Gb/s link rate is presented with the state-of-the art sub-100-ns latency variation for a timing-protocol flow. This is achieved through the application of a gap-filling aggregator, used for the first time in such a mobile fronthaul application.