Next-Gen SDN Tutorial (Advanced)

Welcome to the Next-Gen SDN tutorial!

This tutorial is targeted at students and practitioners who want to learn about the building blocks of the next-generation SDN (NG-SDN) architecture, such as:

• Data plane programming and control via P4 and P4Runtime
• Configuration via YANG, OpenConfig, and gNMI
• Stratum switch OS
• ONOS SDN controller

Tutorial sessions are organized around a sequence of hands-on exercises that show how to build a leaf-spine data center fabric based on IPv6, using P4, Stratum, and ONOS. Exercises assume an intermediate knowledge of the P4 language, and a basic knowledge of Java and Python. Participants will be provided with a starter P4 program and ONOS app implementation. Exercises will focus on concepts such as:

• Using Stratum APIs (P4Runtime, gNMI, OpenConfig, gNOI)
• Using ONOS with devices programmed with arbitrary P4 programs
• Writing ONOS applications to provide the control plane logic (bridging, routing, ECMP, etc.)
• Testing using bmv2 in Mininet
• PTF-based P4 unit tests

Basic vs. advanced version

This tutorial comes in two versions: basic (master branch), and advanced (this branch).

The basic version contains fewer exercises, and it does not assume prior knowledge of the P4 language. Instead, it provides a gentle introduction to it. Check the master branch of this repo if you're interested in the basic version.

If you're interested in the advanced version, keep reading.

Slides

Tutorial slides are available online: http://bit.ly/adv-ngsdn-tutorial-slides

These slides provide an introduction to the topics covered in the tutorial. We suggest you look at it before starting to work on the exercises.

System requirements

If you are taking this tutorial at an event organized by ONF, you should have received credentials to access the ONF Cloud Tutorial Platform, in which case you can skip this section. Keep reading if you are interested in working on the exercises on your laptop.

To facilitate access to the tools required to complete this tutorial, we provide two options for you to choose from:

1. Download a pre-packaged VM with all included; OR
2. Manually install Docker and other dependencies.

Option 1 - Download tutorial VM

Use the following link to download the VM (4 GB):

• http://bit.ly/ngsdn-tutorial-ova

The VM is in .ova format and has been created using VirtualBox v5.2.32. To run the VM you can use any modern virtualization system, although we recommend using VirtualBox. For instructions on how to get VirtualBox and import the VM, use the following links:

• https://www.virtualbox.org/wiki/Downloads
• https://docs.oracle.com/cd/E26217_01/E26796/html/qs-import-vm.html

Alternatively, you can use the scripts in util/vm to build a VM on your machine using Vagrant.

Recommended VM configuration: The current configuration of the VM is 4 GB of RAM and 4 core CPU. These are the recommended minimum system requirements to complete the exercises. When imported, the VM takes approx. 8 GB of HDD space. For a smooth experience, we recommend running the VM on a host system that has at least the double of resources.

VM user credentials: Use credentials sdn/rocks to log in the Ubuntu system.

Option 2 - Manually install Docker and other dependencies

All exercises can be executed by installing the following dependencies:

• Docker v1.13.0+ (with docker-compose)
• make
• Python 3
• Bash-like Unix shell
• Wireshark (optional)

Note for Windows users: all scripts have been tested on macOS and Ubuntu. Although we think they should work on Windows, we have not tested it. For this reason, we advise Windows users to prefer Option 1.

Get this repo or pull latest changes

To work on the exercises you will need to clone this repo:

cd ~
git clone -b advanced https://github.com/opennetworkinglab/ngsdn-tutorial

If the ngsdn-tutorial directory is already present, make sure to update its content:

cd ~/ngsdn-tutorial
git pull origin advanced

Download / upgrade dependencies

The VM may have shipped with an older version of the dependencies than we would like to use for the exercises. You can upgrade to the latest version using the following command:

cd ~/ngsdn-tutorial
make deps

This command will download all necessary Docker images (~1.5 GB) allowing you to work off-line. For this reason, we recommend running this step ahead of the tutorial, with a reliable Internet connection.

Using an IDE to work on the exercises

During the exercises you will need to write code in multiple languages such as P4, Java, and Python. While the exercises do not prescribe the use of any specific IDE or code editor, the ONF Cloud Tutorial Platform provides access to a web-based version of Visual Studio Code (VS Code).

If you are using the tutorial VM, you will find the Java IDE IntelliJ IDEA Community Edition, already pre-loaded with plugins for P4 syntax highlighting and Python development. We suggest using IntelliJ IDEA especially when working on the ONOS app, as it provides code completion for all ONOS APIs.

Repo structure

This repo is structured as follows:

• p4src/ P4 implementation
• yang/ Yang model used in exercise 2
• app/ custom ONOS app Java implementation
• mininet/ Mininet script to emulate a 2x2 leaf-spine fabric topology of stratum_bmv2 devices
• util/ Utility scripts
• ptf/ P4 data plane unit tests based on Packet Test Framework (PTF)

Tutorial commands

To facilitate working on the exercises, we provide a set of make-based commands to control the different aspects of the tutorial. Commands will be introduced in the exercises, here's a quick reference:

Make command	Description
make deps	Pull and build all required dependencies
make p4-build	Build P4 program
make p4-test	Run PTF tests
make start	Start Mininet and ONOS containers
make stop	Stop all containers
make restart	Restart containers clearing any previous state
make onos-cli	Access the ONOS CLI (password: rocks, Ctrl-D to exit)
make onos-log	Show the ONOS log
make mn-cli	Access the Mininet CLI (Ctrl-D to exit)
make mn-log	Show the Mininet log (i.e., the CLI output)
make app-build	Build custom ONOS app
make app-reload	Install and activate the ONOS app
make netcfg	Push netcfg.json file (network config) to ONOS

Exercises

Click on the exercise name to see the instructions:

1. P4Runtime basics
2. Yang, OpenConfig, and gNMI basics
3. Using ONOS as the control plane
4. Enabling ONOS built-in services
5. Implementing IPv6 routing with ECMP
6. Implementing SRv6
7. Trellis Basics
8. GTP termination with fabric.p4

Solutions

You can find solutions for each exercise in the solution directory. Feel free to compare your solution to the reference one whenever you feel stuck.