Vertical Handoff with OpenFlow

Overview:

This tutorial is designed to give an insight into how OpenFlow can be used to conduct network experiments. As background, a vertical handoff is the (ideally seamless) migration of a network connection from one network interface to another of a different technology. An example might be your cell phone transitioning from a WiFi to a 4G connection while streaming a video. Vertical handoffs are traditionally handled by the network infrastructure, leaving providing little-to-no control of the handoff execution at the client. Clemson University and the University of Wisconsin have partnered to develop and test a client-initiated and controlled vertical handoff. This project is being done using GENI resources -- namely Clemson's GENI WiFi and WiMAX testbeds. Further development is also planned in GENI's Orbit testbed at Rutgers.

This vertical handoff project is being developed on physical machines; however, for the purpose of this tutorial, our development environment has been ported to a virtual machine (VM) so all can participate without regard the the unique hardware capabilities of each participant. This tutorial will walk you through how to perform a Layer-2 (L2) handoff using OpenFlow within a virtual machine. As you will discover, because this solution is dependent only on Linux network interface handles, you can apply it to any interface on a physical host. The VM provided has two host-only interfaces and one interface tied to a physical adapter on the host machine. The host-only interfaces communicate with the VMware tap interface added by VMware to the host machine. In this tutorial, we will demonstrate how to run our handoff solution between these host-only interfaces.

Prerequisites:

• Computer with 2G RAM or higher (recommended)
• Windows (turnoff firewall); Mac/Linux (root at terminal)
• VM image (link to Clemson Box account)
• Familiarity with SSH, Linux terminal, Bash and Python scripting
• Basic networking and OpenFlow background

Tools:

• On your host machine (please install before GREESC13 tutorial session):
  • VMware Player: ​http://www.vmware.com/download/player/download.html
  • PuTTY is recommended, a free implementation of Telnet and SSH for all platforms Windows/Mac users: ​http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html Linux users: sudo apt-get install putty
• Within your VM image (we have already installed these items):
  • OpenVPN. This tool is used to create the internal tap interface, from which the traffic is originated: ​http://wiki.debian.org/OpenVPN
  • Floodlight OpenFlow Controller. The OpenFlow controller we use to switch the network traffic. Information: ​http://www.projectfloodlight.org/floodlight/ Installation: ​http://docs.projectfloodlight.org/display/floodlightcontroller/Installation+Guide
  • Open vSwitch (OVS). The open virtual switch that allows a network interface to be OpenFlow-enabled. Information: openvswitch.org Installation: ​http://git.openvswitch.org/cgi-bin/gitweb.cgi?p=openvswitch;a=blob_plain;f=INSTALL;hb=HEAD

Where to get Help:

• Questions/Help: Ryan Izard, ​rizard@g.clemson.edu; Fan Yang, ​fany@clemson.edu
• Floodlight Developers Group: ​https://groups.google.com/a/openflowhub.org/forum/?fromgroups=#!forum/floodlight-dev

Resources:

• Floodlight: ​http://www.projectfloodlight.org/floodlight/
• Handoff Code: ​https://github.com/rizard/openflow-vertical-handoff (work-in-progress...)

Tutorial Instructions

	Part I: Design/Setup Step 1: Design Experiment Step 2: Establish Management Environment Step 3: Obtain Resources
	Part II: Execute Step 4: Configure and Initialize Services Step 5: Execute Experiment Step 6: Analyze and Visualize Experiment
	Part III: Finish Step 7: Teardown Experiment Step 8: Archive Experiment