SDN is starting to be considered by enterprise organizations, and those organizations need to begin to understand what SDN is and how it will affect their IT department. We have assembled a reading list to help people get started with SDN.
Implementing SDN will be like a journey. It isn’t simply learning a new technology and how to configure and troubleshoot it. SDN will require fundamental changes to the operation of networks, integrating them more tightly to the other functions of IT.
We’ve been through this change before with the convergence of voice and data. The voice team and data team needed to work closely together and eventually merged. Cultural changes were required. The same thing will happen with SDN, only the convergence will be between the network team and the remainder of the IT organization. Our estimates are that the adoption of SDN will likely require at least twice the effort and time that the voice-data integration required.
The dynamic nature of SDN will also require adjustment from the entire IT organization. The networking team must become comfortable with automated systems making configuration changes to the network. Network configuration will happen in seconds in order to support rapid changes in virtual machine deployments. New technologies like Containers (see Wake Up to Containers) will exacerbate this trend. Security will change to the whitelist model that is used in SDN. That is a big change from traditional networking’s open approach that used a blacklist security configuration. Applications will communicate with the SDN controller to verify that the network is setup for optimal operation and security.
Some people confuse network automation with SDN. While SDN allows for faster network configuration, that’s only one factor. When applications and the network can share information about their needs and capabilities, new things will happen. For example, QoS classification and marking can be dynamically configured based on individual calls. An application that needs more virtual machine computing capability to handle increases in demand can ask the network where it is best to locate the VMs, based on network loading and latency. The network can also talk back to the applications to communicate changes in network resources, perhaps due to a failure.
To help our customers get up to speed on SDN, we’ve assembled a reading list. It isn’t something that you’re going to consume over a long weekend and come back to work as an expert, ready to convert your network to SDN. Expect to consume parts of it, think on what you’ve learned, maybe re-read some things, think some more, and read some more new things. It will eventually begin to come together. Links to some of the blog posts provide examples of the benefits that SDN brings.
The practical approach to SDN is to start learning about it and implement something small. Create a cross-functional team comprised of members of the networking, security, unified communications, server, and application teams. Identify an application that can be deployed on SDN and implement a proof-of-concept using blade servers and leaf-spine switching fabric. Several networking equipment vendors offer starter kits. Learn how the application can talk with the SDN controller to share information in both directions. Understand where the vendors are with their SDN implementations and how well they support your applications.
Good luck with your journey. Let us know if you would like assistance along the way.
Start with these, which gets you started before diving in deeper.
- Terry Slattery’s Cisco Mid-Atlantic User Group (CMUG) presentation on SDN
- David Mahler with a 15-minute quick Introduction to SDN
He doesn’t include the ability for applications and the network to interact with each other. (See Documents and Papers below for the IEEE paper that David based his presentation upon.)
- For those who learn better by reading, here is the paper that David Mahler references in his Introduction to SDN (the link above).
- Introduction to SDN by Blue Elephant Consulting
- A Gentle Introduction to SDN, Scott Shenker
This is a really good presentation on SDN and why it is important. The key concept is the need for new abstractions that we can use to simplify networking.
- Software-Defined Networking at the Crossroads, Scott Shenker
Another video that refines SDN.
- An Attempt to Motivate and Clarify Software-Defined Networking (SDN), Scott Shenker
- The Future of Networking, and the Past of Protocols, Scott Shenker
- How SDN will Shape Networking, Nick McKeown
Nick is another important researcher in the SDN world.
- Urs Hoezle, SVP Google, on the Google SDN implementation, presented at ONS 2012. https://www.youtube.com/watch?v=JMkvCBOMhno
- A SDN reading list from Google
- A SDN reading list from NEC
- Ivan Pepenljack’s site contains a lot about SDN. Some things are free and others require a subscription.
- Packet Pushers contains articles and podcasts (audio) about SDN.
- Open Networking Foundation, which includes conferences and blogs.
- NetCraftsmen blogs on SDN
- Terry Slattery blogs on nojitter.com, primarily about SDN and UC
- Dan Pitt on migrating to SDN
- SDN Q&A: Brocade Senior Director Aus/NZ, Gary Denman
- Martin Casado’s blog
Martin was the researcher at Stanford who started the idea of SDN.
- Brad Hedlund’s blog
This is one blog post, but Brad has many others that are good reading.
Documents and Papers
Anything by Scott Shenker, Nick McKeown, Nick Feamster, Martin Casado, Jennifer Rexford is worth your time.