Tutorial: OpenFlow -Based Vertical Handoff over WiFi and WiMAX in the Orbit Testbed

Sponsored by the National Science Foundation

Tutorial: OpenFlow-Based Vertical Handoff over WiFi and

WiMAX in the Orbit Testbed

Ryan Izard and KC WangClemson University

GEC18

Sponsored by the National Science Foundation 2GREESC13

Tutorial Objectives• The tutorial covers step-by-step how to use OpenFlow to

experiment with mobile device handoff across two wireless networks (Wi-Fi and WiMAX) in ORBIT

• Key objectives:– Learn how SDN enables a range of possibilities for your

research– Learn multiple ways to program your network

• Ingredients:– Linux network interface bridging (tap and bridge)– Open vswitch (OVS)– Floodlight OpenFlow controller– Perl and bash scripting


Mobile Handoff

Net C Net D

Net A

Net B

Application server

Client M

Provider AOF controller

Provider BOF controller (or non-OF)

Provider A or partner’sOF controller

Provider Aor partner’s

OF controller

• From reactive to proactive networking– Mobile IP: Distributed, reactive (long latency), requires

compatible agents everywhere, provider-dictated– OpenFlow: Centralized, proactive, solutions for diverse network

scenarios, opportunities for both provider and client customization

OpenFlow tunnel


Components and Skills You Can Use Later

• I just want to connect to WiMAX– Also talk to us about SciWiNet, another project for you to use

commercial (Sprint) wireless network for research• I want to experiment with my research on mobile apps,

with mobile device repeatedly handing off between two networks, static or mobile– We plan to put a WiMAX mobile on a campus shuttle, details TBD

• I want to develop a better OpenFlow-based handoff solution– Program OpenFlow controller

• I want to use the OpenFlow flow pusher in other OpenFlow networks or devices.


Deployment Map• Greenville subnet

– covers I-85, I-385, Woodruff shopping district– campus hourly shuttle route

• Clemson subnet– covers campus and part of Clemson downtown

BS1CU-ICAR campus

BS2Hotel

CommercialDistrict

GENI BS1Fluor Daniel

GENI BS2Clemson House

ClemsonDowntown

Greenville Clemson

One BS only


BS1Byrnes Hall

Clemson Coverage Plan – One Sector

Clemson-ICAR shuttle route


Greenville Coverage Plan – Two Sectors

BS1, BS2CU-ICAR campus

Clemson-ICAR shuttle route


Now the fun begins.


• Part I: Design/Setup– Experiment Overview– Configure scripts for experiment

• Part II: Execute– Execute handoff experiment

• Part III: Finish– Determine results– Shutdown nodes



http://groups.geni.net/geni/attachment/wiki/GENIExperimenter/Tutorials/WiMAXOpenFlow/orbit-setup.jpeg


http://groups.geni.net/geni/attachment/wiki/GENIExperimenter/Tutorials/WiMAXOpenFlow/Design-Setup/PCEngine_Diagram.PNG




• Part III: Finish– Shutdown nodes


Setup Experiment / Configure ScriptsExperiment is a simple ping to show handoff between WiFi and WiMAX in the Orbit grid testbed:

1) Login to your client node. (The server and AP are pre-configured for you.)

2) Configure Floodlight.3) Get WiMAX and WiFi interface HW information.4) Configure startup script.5) Configure interface-switching scripts.







Execute ExperimentExperiment is a simple ping to show handoff between WiFi and WiMAX in the Orbit grid testbed:

1) WiFi flows are installed as “initial flows” when setup script is run.

2) Start a ping to the server IP. The packets will be switched out the WiFi interface.

3) Run the WiMAX switching script. The ping packets will be switched out the WiMAX interface.

4) You’ve performed a handoff! Want proof? View the flows and packet counts on each OVS bridge before and after an interface-switch.






Teardown Experiment

When the experiment is done:

Exit SSH session to Orbit image. I will take the nodes down after the experiment.

When experimenting on your own, you may save and modify your Oribit images for future experiments.

Documents

Tutorial: OpenFlow -Based Vertical Handoff over WiFi and WiMAX in the Orbit Testbed