The Cost of Stateless Network Functions in 5G

The adoption of a cloud-native architecture in 5G networks has facilitated rapid deployment and update of cellular services. An important part of this architecture is the implementation of 5G network functions statelessly. However, statelessness and its associated serialization and de-serialization of data and database interaction significantly increase latency. In this work, we take the first steps towards quantifying the cost of statelessness in a cloud-native 5G system. We compare the cost of different state management paradigms, and propose a number of optimizations to reduce this cost. Our preliminary results indicate that sharing user state among 5G functions reduces the overall cost by on an average of 10% in experiments with 100 to 1000 simultaneous requests. Optimizations such as non-blocking calls and custom database APIs also reduce cost, albeit to a lower extent. We believe that the paradigms proposed in this paper can aid operators and software vendors as they design cloud-native 5G networks.