Demystifying the Performance Interference of Co-Located Virtual Network Functions

Network function virtualization (NFV) decouples network functions from the dedicated hardware and enables them running on commodity servers, facilitating widespread deployment of virtualized network functions (VNFs). Network operators tend to deploy VNFs in virtual machines (VMs) due to VM's ease of duplication and migration, which enables flexible VNF placement and scheduling. Efforts have been paid to provide efficient VNF placement approaches, aiming at minimizing the resource cost of VNF deployment and reducing the latency of service chain. However, existing placement approaches may result in hardware resource competition of co-located VNFs, leading to performance degradation. In this paper, we present a measurement study on the performance interference among different types of co-located VNFs and analyze how VNFs' competitive hardware resources and the characteristics of packet affect the performance interference. We disclose that the performance interference between co-located VNFs is ubiquitous, which causes the performance degradation, in terms of VNFs' throughput, ranging from 12.36% to 50.3%, and the competition of network I/O bandwidth plays a key role in the performance interference. Based on our measurement results, we give some advices on how to design more efficient VNF placement approaches.