This episode is a recording of a talk that Dave Lenrow gave at the Stanford Platform Lab Fall Seminar on Dec. 6. Dave is Chief Architect for Next Generation Data Center and Distinguished Engineer at Huawei. He participates in a wide variety of open source networking projects including ONOS, Open Daylight, OPNFV, opensourcesdn.org, and Open-O. He is Chairman of the ONF North Bound Interface (NBI) WG, and a leader in the OSSDN Boulder open source intent reference software project. He has spent more than 20 years driving innovation in digital technology with an emphasis on networks, storage and media. You may want to follow along with Dave's slides, but the talk makes sense without them. The talk's abstract is: The ONF’s North Bound Interface Work Group has been advocating a new interface to infrastructure controllers based on describing what is needed from the system, rather than how the system should provide it. We’ve been trying to create a common NBI that would be used by diverse developers and operators to create a network effect and resulting strong platform and ecosystem. We have been describing this approach as Intent Based networking (IBN) and recently published a consensus based document describing the operating principles of such a system. We define an intent based network system as one with a strict separation of application/workload communication intent, from details about how a network system implements and fulfills such intent (mappings). It turns out that the implementation independent part of the description (the intent) has several valuable properties and the promise to share state in a way that allows massive scale and high performance. To fulfill the promise suggested by this new interface and system architecture, we need to get broad collaboration, and we need to solve some difficult system and platform design problems. The goal of this talk is to get feedback and solicit help from the platform lab in solving some of these problems in an open collaboration. We hope to discuss the role that intent based interfaces could serve in building a big control platform in the coming years. Keith Winstein introduces the talk. The first part of the talk is an introduction to intent-based software-defined networking, which Dave summarizes as, “Don't tell me what to do, tell me what you need.” Intent describes the problem, whereas traditional CLI commands describe the solution to the problem. In intent, you build a model of the type of workloads you have and let a piece of software decide how to implement it. Dave gives an analogy to health care, comparing a request for an aspirin (the status quo in networking) to a request to cure a headache (intent-based networking). An intent-based system breaks networking into “intent” and “mapping” layers, where the mapping layer is the one that resolves the intent into protocols and other implementation-level details. One of the big benefits of intent comes from the ability to run more than one service. A lot of existing SDN controllers can support a single application. Attempting to run more than one application tends to cause them to interfere with each other, since each one tries to modify switch state, such as flow tables, without respecting the other's needs, a “multiple writers” problem. The second part of the talk, which starts about half an hour in, describes a set of open problems. Many of these reference the Big Control Platform, an ongoing Platform Lab project that seeks to build infrastructure for controlling collaborative device swarms. The talk ends with over 20 minutes of questions, beginning at Keith Winstein, Mendel Rosenblum, Bob Lantz, and others. OVS Orbit is produced by Ben Pfaff. The intro music in this episode is Drive, featuring cdk and DarrylJ, copyright 2013, 2016 by Alex. The bumper music is Yeah Ant featuring Wired Ant and Javolenus, copyright 2013 by Speck. The outro music is Space Bazooka featuring Doxen Zsigmond, copyright 2013 by Kirkoid. All content is licensed under a Creative Commons Attribution 3.0 Unported (CC BY 3.0) license.