a hot topic in computer networks today: software- defined networking
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A Hot Topic in Computer Networks Today: Software- Defined Networking. Prof. Jang-ping Sheu High-Speed Communication & Computing Laboratory National Tsing Hua University. Outline. Background and motivation What is SDN ? An open standard- OpenFlow The applications of SDN Challenges - PowerPoint PPT PresentationTRANSCRIPT
國立清華大學高速通訊與計算實驗室NTHU High-Speed Communication & Computing Laboratory
A Hot Topic in Computer Networks Today: Software-
Defined Networking
Prof. Jang-ping Sheu
High-Speed Communication & Computing Laboratory
National Tsing Hua University
2
Outline
Background and motivation
What is SDN ?
An open standard- OpenFlow
The applications of SDN
Challenges
Research resources
3
Outline
Background and motivation
What is SDN ?
An open standard - OpenFlow
The applications of SDN
Challenges
Research resources
4
Internet in Recent Decade Data increasing continuously: Data Center, Cloud
Computing, and Big Data E-business, Video on demand, MOOCs (Massive Open Online
Courses)
More protocols created with Heterogeneity networks
developing VANET (Vehicular Ad-hoc NETwork), WSN (Wireless Sensor
Network), CRN (Cognitive Radio Network)
5Source: Intel 2012 March
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Traditional Networks - Features
Closed equipment Software bundled with hardware Vendor-specific interface
Only vendors can develop for its constrained environments Over specified
Various and complex protocols: OSPF, BGP, DiffServ, NAT, MPLS, and so on.
No uniform standardization Buggy software in the equipment
Routers are with million of lines of source code Cascading failures, vulnerabilities is popular
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Traditional Networks - inconvenience
Operating a network is too complex and expensive To add or move any device, network must be reconfigured,
such as router, switch and firewall Too expensive to change the topology of network
Not easy to control the communications User cannot write the control code except equipment
vendors Long delays to introduce new features
Difficult to customize: Even vendors and third parties are not able to provide
customized cost effective solutions to address their customers’ problems
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Million of linesof source code
6,000 RFCs( Request For Comments)
Billions of gates, Bloated, Power Hungry
Vertically integrated, complex, closed, proprietaryNot suitable for experimental ideas
Specialized Packet Forwarding Hardware
OperatingSystem
Feature Feature
Routing, management, mobility management, access control, VPNs, …
We Need Modify Existing Equipment
Switch
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Vertically integratedClosed, proprietary
Slow innovationSmall industry
SpecializedOperatingSystem
SpecializedHardware
AppAppAppAppAppAppAppAppAppAppApp
SpecializedApplications
HorizontalOpen interfacesRapid innovation
Huge industry
Microprocessor
Open Interface
Linux MacOS
Windows(OS) or or
Open Interface
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Vertically integratedClosed, proprietary
Slow innovation
AppAppAppAppAppAppAppAppAppAppApp
HorizontalOpen interfacesRapid innovation
ControlPlane
ControlPlane
ControlPlane or or
Open Interface
SpecializedControlPlane
SpecializedHardware
SpecializedFeatures
MerchantSwitching Chips
Open Interface
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Outline
Background and motivation
What is SDN ?
An open standard- OpenFlow
The applications of SDN
Challenges
Research resources
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Software-Defined Networking (SDN)
SDN is an approach to networking in which control is decoupled from hardware and given to a software application called a controller Allows network engineers to support a switching
fabric across multi-vendor hardware and application-specific integrated circuit
Allows a stronger intellectual foundation to networking Allows us to define the right abstractions in different
layers Allows us to transfer technology much faster, in both
directions (academic and Industry) Closing the gap with industry
SDN from Traditional Network Device
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Ethernet Switch
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Data Path (Hardware)
Controller (Software)
SDN from Traditional Network Device
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Data Path (Hardware)
Control Path OpenFlow
OpenFlow Protocol (SSL)
Controller
SDN from Traditional Network Device
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OpenFlow Protocol (SSL)
Controller
Ethernet Switch
SDN from Traditional Network Device
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More Detail in SDN
Specialized Packet
Forwarding Hardware
App App App
Specialized Packet
Forwarding Hardware
App App App
Specialized Packet
Forwarding Hardware
App App App
Specialized Packet
Forwarding Hardware
App App App
Specialized Packet
Forwarding Hardware
OperatingSystem
OperatingSystem
OperatingSystem
OperatingSystem
OperatingSystem
App App App
Network Operating System
Control Programs
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More Detail in SDN
Simple Packet Forwarding Hardware
Simple Packet Forwarding Hardware
Simple Packet Forwarding Hardware
Simple Packet Forwarding Hardware Simple Packet
Forwarding Hardware
Network Operating System
Control Programs
Packets Delivering in SDN
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Controller
PC
OpenFlow Switch
OpenFlow Switch OpenFlow Switch
User’s code
Decision?OpenFlowProtocol
User’s Rule
User’s Rule User’s Rule
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Potential Application Model in SDN
Data Centers Public and private clouds
WANs Google WAN Eventually, public WANs
Enterprise networks Greater control, fewer middle boxes
Home networks Outsourced management
Cellular Networks Separation of service from physical infrastructure
Research and Education Networks National backbones College campus networks
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Outline
Background and motivation
What is SDN ?
An open standard- OpenFlow
The applications of SDN
Challenges
Research resource
22
OpenFlow - What is it ?
An open standard for that enables researchers to run experimental protocols in the campus networks we use every day
Network administrators can remotely control forwarding tables by it
Currently being implemented by major vendors Enabled switches now commercially available
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OpenFlowController
OpenFlow Switch
FlowTable
SecureChannel
PCOpenFlow
Protocol
SSL
HW
SW
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OpenFlow - Controller
A controller adds and removes flow entries from the Flow Table on behalf of experiments• A static controller might be a generalization of
VLANs.• More sophisticated controllers that dynamically
add/remove flows as an experiment progresses Researchers might control the complete network of
OpenFlow Switches and be free to decide how all flows are processed
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OpenFlow - Switch
Flow Table, with an action associated with each flow entry, to tell the switch how to process the flow
Secure Channel that connects the switch to controller, allowing commands and packets to be sent between a controller and the switch
OpenFlow Protocol, which provides an open and standard way for a controller to communicate with a switch
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OpenFlow - Flow Table Entry
SwitchPort
MACsrc
MACdst
Ethtype
VLANID
IPSrc
IPDst
IPProt
TCPsport
TCPdport
Rule Action Stats
1. Forward packet to port(s)2. Encapsulate and forward to controller3. Drop packet4. Send to normal processing pipeline
Packet + byte counters
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OpenFlow - Cache flow decisions in datapath
“If header = x, send to port 4”
“If header = ?, send to me”“If header = y, overwrite header with z, send to ports 5,6”
FlowTable
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Deployment Modes In-network: OpenFlow-enabled network infrastructure
(upgraded or green-field) Overlay: Legacy network infrastructure with smart edge devices
New boxes, such as gateways Enhanced kernel bridge (e.g., OpenVSwitch in x86 hypervisors)
Examples: In-network: Google uses OpenFlow-enabled controllers switches to
interconnect their data centers Overlay: AT&T, NTT, eBay, Fidelity Investments, and Rackspace use
OpenStack Quantum and Nicira NVP controller to manage the virtual networks in their clouds
Hybrid: Genesis hosting uses NEC controller in intra-data-center scenario
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Outline
Background and motivation
What is SDN ?
An open standard - OpenFlow
The applications of SDN
Challenges
Research resource
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Benefits from SDN
Network Virtualization Switch based Firewall Multipath Forwarding Congestion Control Identify bugs
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Network Virtualization in SDN
The process of combining hardware and software network resources to be some virtual networks
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Virtualization in Traditional Network
L2 virtualization: VLAN Networks can only support a finite number of
VLANS
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SDN-based Network Virtualization
Each tenant can run his virtual network with controller in SDN.
OpenFlow network removes limitations, allowing administrators to create a flow-based virtual network abstraction.
Computer virtualization Network Virtualization
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SDN-based Network Virtualization
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Switch based Firewall in SDN
OpenFlow switches can emulate Firewall by assigning rules to switches.
Controller
H1
H2
H3
Flow Classifer
Cloud
Block this flow
This packet needs to block
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Traditional Switch Path Forwarding
In traditional switches, forwarding packets use spanning tree algorithm to solve looping problem
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Multipath Forwarding in SDN
Forwarding by rule and central controller’s decision.
Controller
Controller can install multipath roles in SDN switches
Congestion Control by SDN
Controller can get SDN switches information to know if congestion happened.
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Controller Controller gets switches status to decide flow rate
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Identify Bugs by SDN
Identify bugs with systematically tracking down their root cause
When an operational network misbehaves, it is very hard to find the root cause
Allows users to define a Network Breakpoint Capture and reconstruct the sequence of events leading to
the breakpoint
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Outline
Background and motivation
What is SDN ?
An open standard - OpenFlow
The applications of SDN
Challenges
Research resource
Countries in Trial of SDN
68 Trials in 13 Countries
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SDN in University of U.S.A Severing as GENI (Global Environment for Network
Innovations) Networking Substrate
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Challenges
Complex designing solutions
Limited TCAM size
Controller delay and overhead
Multi-controller working together
Migrating from legacy to SDN
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SDN - Data-Plane Challenges
State of Specification Maturity Concerns OF 1.0 single flow table, … OF 1.1 leverages multiple tables
Silicon Concerns Spec is much ahead of silicon development… OF Spec is a
moving target for merchant silicon Merchant silicon is not optimized for OF… supports of
current networking features is a higher priority Specific issues
Scalability of Flow-Matches (limited by TCAM size) Cost concerns
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SDN – Control-Plane Challenges
Control Plane scalability Centralized vs. distributed controllers... Single view of the state of the network, forwarding tables,
… is this a distributed database problem? Interoperability
SDN/NON-SDN Inter-Controller Between different controllers Orchestrating SDNs managed by different controllers …
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SDN- Application-Environments Challenges
Network Resource Abstraction & Conflict Resolution Resource abstraction Conflict resolution among different application actions
Development tools and New Application Paradigm Computing system style application… New class of Network Programming Languages… New tools New development skills… New talents... New education
curriculum…
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Outline
Background and motivation
What is SDN ?
An open standard - OpenFlow
The applications of SDN
Challenges
Research resources
48
Research Platform for SDN Mininet
Network emulator Designed for emulating SDN networks Easy to use High performance (100 nodes on a laptop)
Network OS for Research NOX (C++/Python) http://noxrepo.org Maestro (Rice University) Helios (NEC) Beacon (Java) coming soon, …
Network OS Commerce ONIX [OSDI 2010, Google, Nicira, NEC] Expect others
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OpenFlow Testbed Candidate controllers:
Nicira’s Nox: C++ and python prototyping NTT’s Ryu : python more production level
Candidate switches: Standalone switches
Pica8 (3290): OpenFlow v1.1, a spin-off of Quanta HP (5400zl): either OpenFlow mode or legacy mode. NEC(IP8800): either OpenFlow mode or legacy mode. Pronto: legacy routing stack and OpenFlow enabled features can not be
support in the same VLAN Brocade (CES/CER/MLX/XMR/MLXe): fully support hybrid mode
PC-based switches (decreasing programmability) OVS (OpenVSwitch): pure software based OpenFlow enabled data path Netronome: network processor PCI card NetFPGA (Stanford): research oriented cards
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Thank you !
2011I International Conference on Computer Science an d Network Technology