The Price for Programmability in the Software Data Plane: The Vendor Perspective

Abstract

The killer features of the next-generation 5G mobile standard, including mobile edge computing and network slicing, will be very difficult to support with traditional fixed-function network appliances. Rather, the 5G core will depend on programmable switches, which allow packet processing functionality to be reconfigured on the fly in order to deploy virtualized network functions and service chains instantaneously. With 5G on the close horizon, it has become crucial to identify the price for programmability in the software data plane, considering the expected complexity and scale of the next-generation mobile core. In this paper, we report on a multi-year data-plane scalability study we have conducted for a large mobile vendor. Our results paint a rather pessimistic picture on the current landscape of the programmable software data plane. We find that the prominent programmable switches either do not provide all the features necessary to implement 5G telco pipelines efficiently or struggle to meet the scale, and the performance operators have come to expect from conventional fixed-function appliances. The only exception, ESwitch, remains proprietary. We call for further work on data-plane scalability and sketch some directions for future research.