The Limits of Architectural Abstraction in Network Function Virtualization

Abstract

Network Function Virtualization (NFV) is the paradigm of implementing network services as a network of functions on top of commodity off-the-shelf (COTS) servers. It is of profound interest to telecommunications network operators because of the promise of bringing the economics of data centers into the network. However, existing CPU, memory, and network interface architectures cause network service performance to be sensitive both to the implementation of individual network functions, but also to their placement within an NFV platform. For this reason, emerging NFV standards will confront the challenge of exposing certain platform architectural parameters to enable services to be orchestrated in an effective manner. The goal of the paper is to show that underlying technologies must be exposed to the Orchestrator during service deployment as incorrect placement can have a very significant impact on performance. We illustrate this by describing a “proof-of-concept” implementation of Quality of Service (QoS) for a Broadband Remote Access Service (BRAS)/Border Network Gateway (BNG). Our work focuses on studying performance implications related to PCIe bandwidth constraints, Virtual Network Function (VNF) placement, message buffer (mbuf) size and memory channel utilization.