Efficient traffic monitoring in 5G Core Network

Abstract: 5G is an enabler to several new use cases. To support all of them, the network infrastructure must be flexible and it should adapt to the different situations. This feature is powered by SDN, NFV, and Automation, three of the main pillars on which the 5G network is built.Traditional network management approaches may not be suitable for the 5G Core Network User Plane, which holds strict requirements in terms of latency and throughput. Therefore, Artificial Intelligence agents have been proposed to manage the 5G in a more efficient manner, delivering a more optimized allocation of the resources. This approach requires real-time monitoring of the data passing by the Core Network, a feature not standardized by the current protocols. In this thesis, the design of a monitoring protocol for the 5G Core Network User Plane has been studied, focusing on precise measurement of latencies. Then, a In-band Network Telemetry (INT) framework has been implemented on top of a User Plane Function prototype. The prototype is built on top of a novel User Plane implementation, based on chaining of atomic functions called micro-UPFs (µUPFs).While the main focus of this work has been latency measurement, packet counters, byte counters and Inter Packet Gap values can be collected from the framework, proving the main KPIs of a 5G User Plane. The INT framework has been implemented through two new µUPFs, one for updating the INT metadata and one for collecting them. These metadata are attached to the user packets as GTP-U extended header, maintaining compatibility with the standard protocol. Moreover, the implemented framework allows high flexibility through dynamic tuning of the parameters, providing mechanisms to reduce the amount of telemetry data generated and, thus, the system overhead.The framework has been tested on a physical setup of four server machines, abstracting a Core Network User Plane, connected with 10 Gbps NICs. In all the tests performed, the performances of the User Plane are affected by the new functionalities only when INT metadata are inserted very frequently. The results show that is possible to monitor the three main KPIs of a 5G User Plane without heavily limiting the system performances.