 Frederick Kautz and Nikolay Nikolaev are developers on the Network Service Mesh project, which provides additional networking features for Kubernetes above what is available from Kubernetes CNI networking implementations. 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. 

OVS Orbit

Network Service Mesh, with Frederick Kautz and Nikolay Nikolaev

 Nick Buraglio works in research and education and service provider networking, currently at ESnet, the US Department of Energy's science network, which links sites in the United States and western Europe. In this podcast, he talks about the role of latency monitoring in managing a network. Nick defines the latency that he's talking about: "When most people think of latency, they think of a ping round-trip time. That's one useful data point, but we're talking about very low tolerance and high accuracy latency. You have to have a cellular or GPS clock and a very strong clock source in the system to be able to track it at this level. We use that as a very important part of how we manage our network. That's really what I'm talking about when I talk about latency." Nick discusses the perfSONAR software for monitoring latency over time and for investigating problems as they occur. Some basic live monitoring charts and graphs for ESnet are online at MyESnet. You can contact Nick on Twitter as @forwardingplane or visit his blog at forwardingplane.net. Other episodes of OVS Orbit related to monitoring include Episode 46: In-band Network Telemetry and Episode 6: sFlow. 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. 

Long-Term Network Latency, with Nick Buraglio from ESnet

 There are several challenges toward making it easy for users to add support for new protocols in OVS or, equivalently, adding P4 support to OVS. This talk, given at the Dagstuhl seminar on programmable data planes in April 2019, explains the reasons that OVS doesn't already have these features, what's changing, and likely future directions. The talk includes considerable discussion with the audience. An early statement summarizes the message of the talk: ...I think that it's too hard to add support for new protocols and I think users should be able to do that fairly easily. Currently, it's really hard--it's hard for me in some cases, and if it's hard for me then I'm sure it's hard for everyone else. A little later, this quote covers Ben's philosophy on P4: Why I like P4 is because of my own personal experience with OpenFlow. At Nicira when we started out designing OpenFlow, we designed it for very much a fixed match over basically IPv4 and related fields. We knew from day 1 that that wasn't good enough, I mean, not to mention existing protocols like IPv6 that we couldn't handle, but it seemed pretty obvious that people would want to add their own. Over a couple of years, in my spare time I started tinkering with ideas for how to write a language for specifying what protocols a switch supports. It seemed like there were two possibilities that kept coming up, and yet neither one of them seemed very good. One was basically based on fixed offsets; people kept suggesting this, I think maybe even Nick McKeown suggested this at one point. I kept pointing out that fixed offsets are not going to work very well because offsets change from one packet to another. The other end of the spectrum was somebody just provides a program in some general-purpose language that extracts the headers that you want, and that also seems pretty unsatisfying because it's really hard to take a general-purpose program and look at it in terms of some of its emergent properties. You can't do much with it other than run it. I tried to come up with some languages that fit in between and then when I first saw one of the drafts of the P4 specification, I looked at it and said, "I wish I'd written this." It seems to me that it strikes a really good balance there. The remainder of the talk covers the possible directions forward for OVS and flexible protocol support, including eBPF and AF_XDP. 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. 

User-Configurable Protocol Support for OVS, or Why Doesn't OVS Support P4?

 Brad Cowie and Richard Sanger are members of the WAND Network Research Group at the University of Waikato, in Hamilton, New Zealand. They are both associated with the Faucet project, which develops an open source OpenFlow controller for enterprise networks. The first part of this talk is an introduction to Faucet. The second part talks about how Faucet became involved in SCinet at SC18, the supercomputing conference held annually in Dallas. The talk includes questions from the audience. You may wish to view Brad's slides along with the episode. For more information on Faucet, visit the Faucet website. You can reach Brad as gizmoguy on IRC or @nzgizmoguy on Twitter. Brad Cowie previously spoke with OVS Orbit in Episode 47: Routing a Production Enterprise Network with Faucet. OVS Orbit previously covered Faucet in Episode 45: Faucet and OpenFlow at Allied Telesis, Epsiode 33: Lightning Talks, and Episode 19: The Faucet SDN Controller. For another take on Faucet at SC18, you can listen to Ivan Pepelnjak interview Nick Buraglio in Episode 101 of Software Gone Wild. 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. 

The Faucet Controller at SC18, with Brad Cowie and Richard Sanger from University of Waikato

 Levente Csikor and Gabor Retvari from the Budapest University of Technology and Economics present their talk “The Discrepancy of the Megaflow Cache in OVS” at the Open vSwitch Fall Conference in San Jose in December 2018. A few days later, they visited me to have this discussion for the podcast about their work. This episode is a discussion of their work and their results. For a synopsis of Levente and Gabor's work, please visit the OVS conference page. Slides and video of their ovscon talk are also available. 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. 

The Discrepancy of the Megaflow Cache in OVS, with Levente Csikor and Gabor Retvari from Budapest University of Technology and Economics

 Simon Horman has been an Open vSwitch contributor and committer since 2010. He currently works for Netronome, where his Open vSwitch work centers around hardware offload using the "tc" API integrated into the Linux kernel. This API allows users of Open vSwitch to transparently obtain better performance: when offload is enabled with a compatible network card, Open vSwitch works the same way, but faster. The conversation includes: Categories of NICs with hardware offload The architecture of Netronome NICs How the offload API works Handling state (such as connection tracking state) in hardware offload Limitations of hardware offload, such as memory and other resource limits Extending hardware offload to DPDK The possibility of classification-only offload Offload interaction with the OVS caching hierarchy The cost of offload Kernel politics of the offload API Applications for offload Vendor cooperation across the API Simon Horman is available on Twitter as @horms. For more information on the offload API, you might want to listen to Episode 50, with Andy Gospodarek from Broadcom. 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. 

OVS Hardware Offload, with Simon Horman from Netronome

 Qiuyu Xiao is a Ph.D. student in the department of computer science at the University of North Carolina at Chapel Hill. During the summer of 2018, he was an intern in the Open vSwitch team at VMware. This episode is a talk that Qiuyu gave at the end of his internship, describing his work on encrypted tunnels for OVN. The slides that accompanied the talk are available. To learn more about Qiuyu's work, visit his website, or contact him via email at qiuyu@cs.unc.edu or on Twitter as @QiuyuX. 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. 

Encrypting OVN Tunnels with IPsec, with Qiuyu Xiao from UNC-Chapel Hill

 This episode, recorded in April 2018, was the third in a series of internal VMware tech talks about Open vSwitch. This episode is particularly about OVSDB, the Open vSwitch Database, and particularly about OVSDB from the viewpoint of the client. It talks about the C client library, including how it represents data, the usual way to work with it, and how it interacts with the OVSDB server. It also covers how the C client library supports preparing transactions to send to the server. Part of the talk dissects and explains an OVSDB JSON-RPC transaction created by ovs-vsctl. You can see a similar transaction by running make sandbox in an OVS tree, then ovs-vsctl -vjsonrpc add-br br0 inside the sandbox. Look for the transact operation, Or look at this example, which has been put through a JSON pretty-printer for legibility. The talk concludes with several minutes of questions. One of the questions discusses the C IDL's rendering of the AutoAttach table. You can find this at the top of the file here. Part 1, in episode 55, covered OVSDB from the server and network protocol point of view. 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. 

Introduction to OVSDB, Part 2

 Qiuyu Xiao is a PhD student studying computer science at the University of North Carolina at Chapel Hill. This episode is a talk that Qiuyu gave at VMware in May. It is based on the paper “Personalized Pseudonyms for Servers in the Cloud,” by Qiuyu Xiao, Michael K. Reiter, and Yinqian Zhangyinqian, originally published in 2017 at Proceedings on Privacy Enhancing Technologies. You may wish to follow along with Qiuyu's slides. The paper's abstract is: A considerable and growing fraction of servers, especially of web servers, is hosted in compute clouds. In this paper we opportunistically leverage this trend to improve privacy of clients from network attackers residing between the clients and the cloud: We design a system that can be deployed by the cloud operator to prevent a network adversary from determining which of the cloud’s tenant servers a client is accessing. The core innovation in our design is a PoPSiCl (pronounced “popsicle”), a persistent pseudonym for a tenant server that can be used by a single client to access the server, whose real identity is protected by the cloud from both passive and active network attackers. When instantiated for TLS-based access to web servers, our design works with all major browsers and requires no additional client-side software and minimal changes to the client user experience. Moreover, changes to tenant servers can be hidden in supporting software (operating systems and web-programming frameworks) without imposing on web-content development. Perhaps most notably, our system boosts privacy with minimal impact to web-browsing performance, after some initial setup during a user’s first access to each web server. You can reach Qiuyu at qiuyu@cs.unc.edu or on Twitter as @QiuyuX. Related episodes. 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. 

Personalized Pseudonyms for Servers in the Cloud, with Qiuyu Xiao from UNC-Chapel Hill

 Ansis Atteka is a developer on the Open vSwitch team at VMware. This episode is a recording of a talk that Ansis gave at VMware in May. He covers techniques for debugging on Linux, in particular how to trace through processes using strace, trace-cmd, and other tools. You may want to follow along with Ansis's slides. You can contact Ansis at aatteka@ovn.org. 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. 

Generic Linux Debugging, with Ansis Atteka from VMware

 Matt Layher and Armando Migliaccio are engineers focusing on networking at DigitalOcean, a cloud service provider. In April, Justin Pettit and I sat down with them at DigitalOcean HQ in New York City. This episode is our discussion, which ranges from how DO first began using Open vSwitch, the DO approach to network control, to scale and performance issues, upgrade strategy, and the Open vSwitch code that DigitalOcean itself is working to contribute. Previously, Matt gave a talk at Open vSwitch 2017 Fall Conference about the use of Go with Open vSwitch at DigitalOcean. 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. 

Networking with OVS at DigitalOcean, with Matt Layher and Armando Migliaccio from DigitalOcean

 Paul Chaignon is a grad student at Orange and Inria. In this episode, Paul talks about Oko: Extending Open vSwitch with Stateful Filters, a paper written with co-authors Kahina Lazri, Jérôme François, Thibault Delmas, and Olivier Festor. Paul presented this research at SOSR '18 in March 2018. The paper has the following abstract: With the Software-Defined Networking paradigm, software switches emerged as the new edge of datacenter networks. The widely adopted Open vSwitch implements the OpenFlow forwarding model; its simple match-action abstraction eases network management, while providing enough flexibility to define complex forwarding pipelines. OpenFlow, however, cannot express the many packets processing algorithms required for traffic measurement, network security, or congestion diagnosis, as it lacks a persistent state and basic arithmetic and logic operations. This paper presents Oko, an extension of Open vSwitch that enables runtime integration of stateful filtering and monitoring functionalities based on Berkeley Packet Filter (BPF) programs into the OpenFlow pipeline. BPF programs attached to OpenFlow rules act as intelligent filters over packets, while leaving the packets unmodified. This approach enables the transparent extension of Open vSwitch's flow caching architecture, retaining its high-performance benefits. Furthermore, the use of BPF allows for safe runtime extension and prevention of switch failures due to faulty programs. We compare our implementation based on Open vSwitch-DPDK to existing approaches with comparable isolation properties and measure a near 2x improvement of performance. You can contact Paul on Twitter as @pchaigno. 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. 

Oko: Extending Open vSwitch with Stateful Filters, with Paul Chaignon from Orange Labs and Inria Nancy

 Han Zhou is an architect working on highly scalable and reliable SDN solutions for eBay's cloud infrastructure. He is an active contributor in OpenStack and OVS/OVN. Before eBay, he has been working in networking area for more than 10 years in Cisco and Nokia. In OVN, the ovn-controller daemon runs on each hypervisor. It obtains logical flows from the OVN southbound database, transforms them into "physical flows," and pushes the physical flows into ovs-vswitchd over an OpenFlow connection. In the current implementation, whenever any of the tables in the OVN southbound database changed, the daemon would fully recompute all of the physical flows to be pushed into ovs-vswitchd. With a sufficiently large setup, this is expensive. This talk is about Han's patches to make computation in ovn-controller incremental, so that a small change in the input causes only a small amount of computation. Some of the talk is easier to follow if you view the slides (PDF). Han was previously featured in OVS Orbit in episode 36, where he spoke about Baker, an approach used by eBay to combine OVN with Kubernetes. 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. 

Incremental Processing with ovn-controller, with Han Zhou from eBay

 Leonid Ryzhyk is a senior researcher in the VMware Research Group. The main theme of his work is applying formal methods to build better operating systems and networks. Before joining VMware, Leonid received his PhD from University of New South Wales and NICTA. Leonid has also worked as a researcher at NICTA, as a postdoc at University of Toronto and at Carnegie Mellon University, and as a researcher at Samsung Research America. In OVN, the ovn-northd daemon acts as an interface and a translator between OVN's northbound and southbound databases. With the existing implementation, any change in the northbound database causes ovn-northd to do a full recomputation of the complete contents of the southbound database. For a large network, this is slow—it can take multiple seconds of CPU time—regardless of the size of the change in the northbound database. Therefore, even a small change, such as adding or removing a single port or a single VM, can take a relatively long time to be realized in the network. In this talk, Leonid presents a prototype for a solution to the problem. The solution implements incremental computation using a system called Differential Dataflow, which is based on the Datalog language for database queries. Because Datalog is not a particularly friendly language for developers who are not already accustomed to it, Leonid also layered syntactic sugar over it called FTL, for Flow Template Language, which is inspired by the FLWOR syntax from XQuery. Some of the talk is easier to follow if you view the slides (PDF). You can contact Leonid via email at lryzhyk@vmware.com. Leonid previously appeared in OVS Orbit in episode 44 on the Cocoon-2 network programming system. Episode 5, with Teemu Koponen and Yusheng Wang, touched on related concepts with its coverage of the nlog language which is also based on Datalog. 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. 

Toward Leaner, Faster ovn-northd, with Leonid Ryzhyk from VMware Research Group

 Alex Ellis founded and leads the OpenFaaS project, which is an open source implementation of a serverless framework. This episode is an interview with Alex. We talk about serverless functions and OpenFaaS, how OpenFaaS compares to other serverless frameworks, how networking works in OpenFaaS, open source communities, and other related topics. We also take on a couple of questions asked by listeners on Twitter. For more information about OpenFaaS, visit openfaas.com. To get in touch with Alex, you can tweet to him as @alexellisuk. 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. 

OpenFaaS, with Alex Ellis from VMware

Interviews and topics of interest to Open vSwitch developers and users, published twice a month, hosted and produced by Ben Pfaff.

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OVS Orbit

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