Software-Defined Networking in Access Networks: Opportunities, Challenges, and Choices

Software-Defined Networking proposes to fundamentally change the current practice of network control. The two basic ideas are Centralized State Control and Uniform Device Abstraction, which support the Software-Defined promise. SDN has made significant progress. The opportunities of SDN in carrier access networks have been largely ignored by both industry and academia. In access networks, Quality-of-Service QoS oriented bandwidth management is more critical; the flexible QoS provisioning could be the most important opportunity for SDN. In this position paper, the authors show that the unique characteristics of access networks pose significant challenges to the two basic ideas. Contrary to the common agreement on "match-action" abstraction, the authors argue that the object-oriented abstraction might be a better choice for access networks to make a better software-defined implementation.