1. OpenFlow: Enabling Innovation in Campus Networks
ACM SIGCOMM Computer Communication Review 2008
Nick McKeown
Tom Anderson
Hari Balakrishnan
Stanford University
University of Washington
MIT
Guru Parulkar
Larry Peterson
Jennifer Rexford
Princeton University
Scott Shenker
Jonathan Turner
University of California, Berkeley
Washington University in St. Louis
葉幸宜
2013/5/30

2. Outlines Introduction and Motivation OpenFlow Conclusion Goal Concepts
Network Architecture
Flow Table Structure
Controller
More Examples
Conclusion
2013/5/30

3. Introduction and Motivation
Experiments we’d like to do
Mobility Management
New Naming/Addressing Schemes
Network Access Control
If we design our own prototypes …
Closed network
No way to test the prototypes
現在的網路還是有很多值得改善的地方，
像是改善手機換手的方法，
用一個新的protocol取代IP，
或是用新的方法去做network access control的問題。
但是，當我們研發出新的prototype時，
因為現在網路是封閉的，
沒有辦法讓我們把prototype實際load到真正的網路上做測試，
都只能在實驗室跑模擬，
所以往往這些prototype都是未經測試的，
不知道它的實際效能還有可靠性。
2013/5/30

4. Introduction and Motivation
Why Internet is closed for innovations?
Commercial vendor won’t open software and hardware development environment
Complexity to support
Market protection & Barrier-to-entry for competitors
Existing Solutions
Software only
Performance is not good
Hardware/Software
Fanout too small
那為什麼我們的網路會是封閉的呢?
因為網路供應商不希望這些實驗的封包在他們的機器上跑，
他們怕這些prototype沒有設計好，會讓整個網路當掉。
第二個點是因為他們不希望公開他們產品內部的設計，有商業上的原因。
那現在能測試prototype的方法大致上有兩種。
第一種是用軟體去模擬結果，
但這樣子太慢了。
第二種是結合hardware/software的機器，
但他的port太少了，
沒有辦法反映到真正網路的狀況。
2013/5/30

5. OpenFlow Goal Open Platform Bring future Internet to legacy Internet
For researchers to test new ideas at scale production networks
Without requiring vendors to expose internal workings
Bring future Internet to legacy Internet
所以呢，就有openflow的誕生。
它的目的是提供一個open的平台，
讓researchers能夠透過openflow protocol定義好的format，
實際在真實網路上控制，測試他們的prototype。
除了這個目的之外，openflow設計的架構，
也不需要這些網路供應商公開他們內部的設計，
也不會影響到原本網路的運作。
這樣就可以在舊有網路中研發新的架構。
2013/5/30

6. OpenFlow Protocol (SSL) Software  Control Plane
OpenFlow’s Concept
OpenFlow Controller
OpenFlow Protocol (SSL)
Ethernet Switch
Software  Control Plane
Control Plane
OpenFlow
Openflow 是架構在Ethernet switch上的。
原本的switch分成control plane 和 data plane。
Control plane就是設定一些rules，
讓data plane跟去這些rules對封包做處理。
那Openflow最主要的概念就是他讓researcher透過controller，
可以自訂rules，去控制封包的走向，
而且不會動到原本的封包。
Hardware  Data Plane
Hardware  Data Plane
2013/5/30

7. OpenFlow Network Architecture
OpenFlow Switch specification
OpenFlow-enable
Commercial Switch
OpenFlow
Protocol PC
Normal
Software
Secure
Channel
SSL SW
OpenFlow
Controller
Normal
Datapath
Flow
Table HW
2013/5/30

8. OpenFlow Flow Table Structure
OpenFlow Switch
Rule
Action
Statistics
Normal
Software
Secure
Channel SW HW
Normal
Datapath
Flow
Table
Packet + byte counters
Forward packet to port(s)
Encapsulate and forward to controller
Drop packet
Send to normal processing pipeline
Switch
Port
MAC
src
MAC
dst
Eth
type
VLAN ID IP
Src IP
Dst IP
Prot
TCP
sport
TCP
dport
2013/5/30

9. OpenFlow Flow Table Structure
OpenFlow Switch
Rule
Action
Statistics
Normal
Software
Secure
Channel SW HW
Normal
Datapath
Flow
Table
Packet + byte counters
Forward packet to port(s)
Encapsulate and forward to controller
Drop packet
Send to normal processing pipeline
Switch
Port
MAC
src
MAC
dst
Eth
type
VLAN ID IP
Src IP
Dst IP
Prot
TCP
sport
TCP
dport
2013/5/30

10. OpenFlow Flow Table Example
Ethernet Switching
IP Routing
Application Firewall
Switch
Port
MAC
src
MAC
dst
Eth
type
VLAN ID IP
Src IP
Dst IP
Prot
TCP
sport
TCP
dport
Action
* * :2D * * * * * * * Port5
Switch
Port
MAC
src
MAC
dst
Eth
type
VLAN ID IP
Src IP
Dst IP
Prot
TCP
sport
TCP
dport
Action
* * * * * * * * * Port3
Switch
Port
MAC
src
MAC
dst
Eth
type
VLAN ID IP
Src IP
Dst IP
Prot
TCP
sport
TCP
dport
Action
* * * * * * * * * Drop
2013/5/30

11. OpenFlow Controller Centralized intelligential agency
Allow multiple researchers create their accounts to control the flows independently
Add or remove flow-entries
NOX is an open-source OpenFlow Controller
NOX Controller
OpenFlow Switch
OpenFlow Switch
OpenFlow Switch
2013/5/30

12. Secure Channel SSL Connection Controller discovery protocol
Encapsulate packets for controller
Send link/port state to controller
2013/5/30

13. OpenFlow Operation Example
Amy Access Control Scheme!
Rules
Rules
Rules
Rules
OpenFlow
Switch
Flow
Table PC
Controller
Flow
Table
OpenFlow
Switch
OpenFlow
Switch
Flow
Table
OpenFlow
Switch
Flow
Table
2013/5/30

14. OpenFlow Operation Example
Amy Access Control Scheme!
If Rule = x, send to port 4
If Rule = y, drop it
If Rule = ?, send to controller
Else, send to normal pipeline
Amy
OpenFlow
Switch
Flow
Table PC
Controller
Flow
Table
OpenFlow
Switch
OpenFlow
Switch
Flow
Table
OpenFlow
Switch
Flow
Table
2013/5/30

15. OpenFlow Operation Example
Amy Access Control Scheme!
If Rule = x, send to port 4
If Rule = y, drop it
If Rule = ?, send to controller
Else, send to normal pipeline
Amy
OpenFlow
Switch
Flow
Table PC
Controller
Flow
Table
OpenFlow
Switch
OpenFlow
Switch
Flow
Table
OpenFlow
Switch
Flow
Table
2013/5/30

16. OpenFlow Operation Example
Amy Access Control Scheme!
If Rule = x, send to port 4
If Rule = y, drop it
If Rule = ?, send to controller
Else, send to normal pipeline
Amy
OpenFlow
Switch
Flow
Table PC
Controller
Flow
Table
OpenFlow
Switch
OpenFlow
Switch
Flow
Table
OpenFlow
Switch
Flow
Table
2013/5/30

17. OpenFlow Operation Example
Amy Access Control Scheme!
If Rule = x, send to port 4
If Rule = y, drop it
If Rule = ?, send to controller
Else, send to normal pipeline
Amy
OpenFlow
Switch
Flow
Table PC
Controller
Flow
Table
OpenFlow
Switch
OpenFlow
Switch
Flow
Table
OpenFlow
Switch
Flow
Table
2013/5/30

18. OpenFlow Operation Example
Amy Access Control Scheme!
If Rule = x, send to port 4
If Rule = y, drop it
If Rule = ?, send to controller
Else, send to normal pipeline
Amy
OpenFlow
Switch
Flow
Table PC
Controller
Flow
Table
OpenFlow
Switch
OpenFlow
Switch
Flow
Table
OpenFlow
Switch
Flow
Table
2013/5/30

19. OpenFlow Operation Example
Amy Access Control Scheme!
If Rule = x, send to port 4
If Rule = y, drop it
If Rule = ?, send to controller
Else, send to normal pipeline
Amy
OpenFlow
Switch
Flow
Table PC
Controller
Flow
Table
OpenFlow
Switch
OpenFlow
Switch
Flow
Table
OpenFlow
Switch
Flow
Table
2013/5/30

20. OpenFlow Operation Example
Amy Access Control Scheme!
If Rule = x, send to port 4
If Rule = y, drop it
If Rule = ?, send to controller
Else, send to normal pipeline
Bob
OpenFlow
Switch
Flow
Table PC
Controller
Flow
Table
OpenFlow
Switch
OpenFlow
Switch
Flow
Table
OpenFlow
Switch
Flow
Table
2013/5/30

21. OpenFlow Operation Example
Amy Access Control Scheme!
If Rule = x, send to port 4
If Rule = y, drop it
If Rule = ?, send to controller
Else, send to normal pipeline
Bob
OpenFlow
Switch
Flow
Table
O-Flow
Table PC
Controller
Flow
Table
OpenFlow
Switch
OpenFlow
Switch
Flow
Table
OpenFlow
Switch
Flow
Table
2013/5/30

22. More Examples for OpenFlow
Switch
Port
MAC
src
MAC
dst
Eth
type
VLAN ID IP
Src IP
Dst IP
Prot
TCP
sport
TCP
dport
Action
Network Management and Access Control
Ex: Phones can only use HTTP service
VLANs
Mobile wireless VoIP clients
Allowing seamless handover
Non-IP network
OpenFlow packets could be any kinds of formats
Processing packets rather than flows
2013/5/30

23. OpenFlow Products
NEC HP
Pronto
2013/5/30
13/14

24. Conclusion
OpenFlow
Standard way to control flow-tables in commercial switches and routers
An open development environment for all researchers
Real environment for Future Internet Technologies
2013/5/30