Designing Controller Abstractions for Software-Defined Networks

March 14, 2014
Joshua Reich | Princeton University

Today’s networks apply many different, yet often overlapping, pieces of control logic to packetized network traffic. Each packet must be routed, monitored, blocked, balanced, and/or redirected: dependent on both the packet’s properties and operator requirements. Moreover, this control logic must constantly adapt to a changing landscape in which links go up and down; users arrive and depart; traffic demands fluctuate; hosts are compromised and patched; and operator requirements change. Software-Defined Networking (SDN) enables applications to realize these tasks by directly updating network switch routing tables.

Yet, today’s popular SDN controller platforms provide only relatively low-level facilities for programming network switches. These controllers offer limited support for creating modular network controllers and, even less, for encoding dynamic control logic in a structured, compact, and intuitive manner. As a result, SDN controllers are challenging to write, hard to reason about, difficult to reuse or combine, and prone to bugs.

In this talk, I will describe a progression of new programmer constructs and runtime concepts for SDN that are embodied in our Pyretic SDN Controller Platform and PyResonance Library. I will explain how together these provide a platform upon which better SDN controllers can be created. In particular, I will cover abstractions in both our SDN language and runtime architecture for supporting modularity, querying network state, and compactly encoding controller dynamics.

Speaker Details

Dr. Joshua Reich is a postdoctoral researcher in the Department of Computer Science, Princeton University. His research on networked systems brings together computation (end hosts) and communication (network switches), enabling systems that leverage the combined strength of hosts and switches.

Joshua received his Ph.D. in Computer Science from Columbia University in 2011. He was selected as an NSF/CRA Computing Innovation Fellow in the 2011 Cohort. He was awarded Best Student Demo at ACM MobiCom/MobiHoc 2007, was an ACM SRC Finalist at SIGCOMM 2010 and received the NSDI Community Award in 2013. Joshua’s dissertation work on scalable virtual machine image streaming led to the founding of a startup, Infinio Systems Inc.