OFNet
An Open Flow Network Emulator,
Controller/SDN App Testing/
Debugging Framework.
Ganesh H. Shankar
ganesh@sdninsights.org
Mininet
Emulated Openflow Network on Laptop
SDN Controller
Mininet is great..
• However, it is not enough !
• Challenges of SDN
– Debugging is hard
– Reliability – ‘ping’ isn’t good enough 
– Adoption challenges
• Learnings from Stanford’s OF N/W deployment (Paper – Maturing of OpenFlow and Software-Defined Networking through Deployments)
- Flow Setup Time (and short lived flows)
- Limited CPU cycles in hybrid OF switches
- Limited TCAM resources – flow setup policy – Proactive vs. Reactive
OFNet
Network Health Dashboard
SDN Controller
Sniffer
Emulated Openflow Network
Debugger
Traffic Generator
OFNet context – runs on a laptop
Easily Create Openflow N/W with arbitrary
topology
Programmable Traffic Generator and Performance Dash Board
Visual Debugger – Animated spatial View of
messages flow b/w controller and switches
Temporal View – Auto Generated Sequence Diagram of
message flows b/w controller and switches
OFNet – Use Cases
• Qualitative Analysis
– Qualitative comparisons of different controllers
– To gain confidence with near realistic deployments
• Control plane debugging
• Quality assurance of controller – CHO testing
• Easy scripting for automated tests – not locked
into a shell
• Real life traffic generation beyond ping
• Of course as another OF emulator –
education/training
Future Work (when time permits)
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Apache v2 licensed open source . More info here (http://www.sdninsights.org/)
(Site under construction)
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Control Plane and Data plane correlation
Large L2 network – emulated networks connected using VXLAN
Large Cloud Emulation Platform
Overlay & Underlay network emulation
– OF Underlay
– Overlay running on VMs
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Light weight VM emulation using n/w name space
Test bed for studying
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Overlay – Underlay interactions (Opaque underlay criticism)
Scheduling, Performance modeling, Visibility Algorithms