ons14-testbed - Usc - University of Southern California

Try Before you Buy:
SDN Emulation with (Real) Interdomain Routing
Brandon Schlinker⋆, Kyriakos Zarifis*, Italo Cunha♮, Nick Feamster †,
Ethan Katz-Bassett*, and Minlan Yu*
University of Southern California, California, USA⋆
Universidade Federal de Minas Gerais, Minas Gerais, Brazil♮
Georgia Institute of Technology, Georgia, USA†
Open Networking Summit
Santa Clara, California, USA
March 2014
SDN Presents New Questions for Network Operators
Questions in Legacy Networks:
Protocol(s) to Use
Internal Routing (IGPs: OSPF, RIP)
SDN uses centralized controller to make
decisions and focuses on forwarding, not routing
Questions in SDN Networks:
BGP scalability
Controller scalability, switch performance
Equipment Vendor
Single CLI
Support for vendor-specific technologies
Controller capabilities, interoperability
SDN Creates New Challenges for Operators
For a Network Operator, SDN =
New interactions
New components that require redundancy
New scalability and management issues
How Does SDN Impact my Network?
Overwhelmed Network Operator
New Data Centers: Great Environments for Deploying SDN
Greenfield environment – all new equipment purchased at once
Homogeneous network -- 100% SDN infrastructure
Built from the ground-up, no risk of downtime during setup
One administrative domain, little interaction with other networks
What about existing ISP and Enterprise Networks?
ISP Backbone Network
Existing Networks Built Piecemeal Over Multiple Years
Provider Started at East Coast with One Equipment Vendor
Existing Networks Built Piecemeal Over Multiple Years
Expanded to West Coast With Different Equipment Vendor
Multiple Technologies Support Large Networks
Different Technologies Used Across Existing Network
Different IGPs (OSPF, RIP), Route Reflectors for BGP scalability, Middleboxes
Company acquisitions, sudden growth, vendor specific technologies → heterogeneity
Large Networks Have Interactions with Other Networks
Multiple Points of Presence for Interacting with Other Networks
Interactions will continue to use BGP protocol for foreseeable future (even with SDN)
These interactions are important → they define internal traffic patterns
Other Existing Networks Have Similar Problems
Other Networks May Not Be As Large, But Will Face Similar Problems
ISPs, Enterprise Networks, Educational Networks, Service Providers
Highly Diverse Network Ecosystem
Lots of custom configurations, protocols, hidden interactions, outdated decisions
Opposite of environment typically discussed when we talk about SDN
Realities of Transitioning to SDN
Takes time to migrate existing networks
Some operators not ready to migrate portions of their network to SDN technologies
BGP isn’t going away soon (still need to interconnect the Internet)
Need Hybrid Network for Foreseeable Future
Need to ensure different technologies in hybrid network play nice
Network Operators….
How Does an Operator Make Sure SDN Plays Nice In Their Existing Network?
What Tools Can These Use To Understand SDN’s Impact?
Mininet Enables Emulation of SDN Networks
Mininet Lacks Support for Emulating Existing Networks…
Lacks Emulation Support for Key Components in Today’s Networks:
Inter-domain routing (BGP between multiple AS)
Intra-domain routing (Legacy IGPs, such as OSPF, RIP)
Cannot support
hybrid networks
Emulation Limited Regardless of Emulator
Impossible to Emulate
Cannot accurately emulate peer ISPs:
Unpredictable routes, failures, policies, topologies, business & technical goals
We need more than emulation...
Comprehensive Network Emulation of Intra-domain
combined with
Inter-domain Connectivity with Real Networks
MiniNExT’s Extends Mininet’s Emulation Support
Extends Mininet to Support BGP and IGP Protocols
Now can support any network type, including hybrid networks
Requires significantly less resources than emulation with virtual machines
MiniNExT Goes Beyond Emulation with Real Connectivity
BGP Sessions Multiplexed to
Provide Real Connectivity
Combines Emulated Network with Real BGP Connectivity
Multiplexes a real network’s existing BGP sessions
Enables emulated and operational network to communicate with peers via BGP
MiniNExT Translates Network 1:1 into Sandbox Environment
Real Network
networks can
at the same time
MiniNExT Combines Emulated Network with Real BGP
Real BGP Sessions
Emulated with MiniNExT on a laptop
MiniNExT Enables SDN Experiments
Let’s Change The Data Center Network to SDN
MiniNExT Enables SDN Experiments
New SDN Data Center (All Other Components The Same)
MiniNExT Emulated Networks Can Exchange Routes, Traffic
MiniNExT Helps Operators Assess SDN’s Impact
Key Takeaways on MiniNExT:
Enables 1:1 translation of any network into a sandbox environment
Helps network operators take a holistic look at how SDN will impact their networks
Makes it easier to define network transition plans with confidence
Additional Information on MiniNExT:
Talk with me here at the conference
Brandon Schlinker, bschlink@usc.edu
GitHub Repository: MiniNExT