Software-defined Networks
October 2009
With Martin Casado and Scott Shenker
And contributions from many others
Outline
Trends
– Towards “Software-defined Network”
– Towards “Slicing” of network infrastructure
– Government role
We have lost our way
Routing, management, mobility management,
access control, VPNs, …
App
App
App
Operating
System
Specialized Packet
Forwarding Hardware
Million of lines
of source code
5400 RFCs
Barrier to entry
500M gates
10Gbytes RAM
Bloated
Power Hungry
Many complex functions baked into the infrastructure
OSPF, BGP, multicast, differentiated services,
Traffic Engineering, NAT, firewalls, MPLS, redundant layers, …
An industry with a “mainframe-mentality”
Reality
App
App
App
App
Operating
System
App
App
Operating System
Specialized Packet
Forwarding Hardware
Specialized Packet
Forwarding Hardware
• Lack of competition means glacial innovation
• Closed architecture means blurry, closed interfaces
Glacial process of innovation made
worse by captive standards process
Deployment
Idea
Standardize
Wait 10 years
•
•
•
•
Driven by vendors
Consumers largely locked out
Lowest common denominator features
Glacial innovation
Change is happening in non-traditional markets
App
App
App
Network Operating System
Ap
p
Ap
p
Ap
p
Operating
System
Ap
p
Specialized Packet
Forwarding Hardware
Ap
p
Ap
p
Ap
p
Ap
p
Operating
System
Ap
p
Specialized Packet
Forwarding Hardware
Operating
System
Ap
p
Specialized Packet
Forwarding Hardware
Ap
p
Ap
p
Operating
System
Ap
p
Ap
p
Ap
p
Operating
System
Specialized Packet
Forwarding Hardware
Specialized Packet
Forwarding Hardware
The “Software-defined Network”
2. At least one good operating system
Extensible, possibly open-source
3. Well-defined open API
App
App
App
Network Operating System
1. Open interface to hardware
Simple Packet
Forwarding
Hardware
Simple Packet
Forwarding
Hardware
Simple Packet
Forwarding
Hardware
Simple Packet
Forwarding
Hardware
Simple Packet
Forwarding
Hardware
Slicing the physical network
Isolated “slices”
App
App
Network
Operating
System 1
Many operating systems, or
Many versions
App
App
Network
Operating
System 2
App
App
App
Network
Operating
System 3
App
Network
Operating
System 4
Open interface to hardware
Virtualization or “Slicing” Layer
Open interface to hardware
Simple Packet
Forwarding Hardware
Simple Packet
Forwarding Hardware
Simple Packet
Forwarding Hardware
Simple Packet
Forwarding Hardware
Simple Packet
Forwarding Hardware
Consequences
More innovation in network services
– Owners, operators, 3rd party developers,
researchers can improve the network
– E.g. energy management, data center
management, policy routing, access control,
denial of service, mobility
Lower barrier to entry for competition
– Healthier market place, new players
Is change likely?
The change has already started
In a nutshell
– Driven by cost and control
– Started in data centers…. and may spread
– Trend is towards an open-source,
software-defined network
– Growing interest for cellular and telecom networks
Example: New Data Center
Cost
Control
200,000 servers
Fanout of 20 a 10,000 switches
$5k commercial switch a $50M
$1k custom-built switch a $10M
1. Optimize for features needed
2. Customize for services & apps
3. Quickly improve and innovate
Savings in 10 data centers = $400M
Large data center operators are moving towards defining their own network in software.
Trend
App
App
App
Windows
Windows
Windows
(OS)
(OS)
(OS)
Linux
Linux
Linux
App
App
App
Mac
Mac
Mac
OS
OS
OS
Virtualization layer
x86
(Computer)
Computer Industry
Controller11
NOX
Controller
(Network OS)
Controller
Controller
Network
OS
22
Virtualization or “Slicing”
OpenFlow
Network Industry
How can government help?
What NSF is supporting
Trials of “Software-defined Network” & OpenFlow
US College Campus Trials
– UW, Georgia Tech, Princeton, Rutgers,
UW-Madison, Clemson, Indiana, Stanford
– Vendors with prototype OpenFlow:
Cisco, Juniper, HP, NEC, Ciena, Arista, Quanta, ….
National College Backbone Trials
Data Center Clusters (with Google, Yahoo!, HP, etc.)
Nationwide OpenFlow Trials
UW
Univ
Wisconsin
Princeton
Stanford
NLR
Indiana
Univ
Rutgers
Internet2
Clemson
Georgia
Tech
Production deployments
before end of 2010
The role of government
When funding new infrastructure
– Mandate open interface to equipment (OpenFlow)
– Recommend trials of “software-defined networks”
Risk
Invest in the wrong equipment, and we are
stuck with “same old” equipment for 10 years
Software-defined Wireless Networks
Applies equally to wireless networks
Mobility manager, AAA, billing,
MVNO, Wireless service provider, …
App
App
App
Network Operating System
Simple Packet
Forwarding
Hardware
Simple Packet
Forwarding
Hardware
Simple Packet
Forwarding
Hardware
Simple Packet
Forwarding
Hardware
WiFi, WiMAX, LTE
Simple Packet
Forwarding
Hardware
Outline
Trends
– Towards “Software-defined Network”
– Towards “Slicing” of network infrastructure
– Government role
Dream
– Making available the abundant wireless capacity
around us
– Technical trend
– Business hurdles
Observations
• We are not short of wireless capacity: It is
abundant, but off limits
• Cell phone today = 6 radios
• Cell phone in 2020 = 20 radios?
Can we:
– Decouple service providers from physical
networks?
– Allow user to decide to connect to any or many
wireless networks simultaneously?
Service Providers and Infrastructure
Services
App
App
“Vodafone”
OS
Services
App
App
“AT&T”
OS
Services
App
App
“Newco”
OS
Open flow-based interface
My Employer
A home
WiFi AP
WiFi AP
Slicing
Slicing
Slicing
WiFi AP
Service providers in cloud
WiMAX
Nationwide infrastructure owners
Slicing
WiFi AP
LTE
WiMAX
LTE
LTE
Thank you!