1.
Software-Defined Networking
Robert Keahey
IEEE-Consultants’ Network of Silicon Valley – 2012/10/16

2.
Agenda
 SDN
 Trends, Drivers, Models, Use Cases
 OpenFlow
 Network Virtualization
 Essential things to know
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3.
The Next (R)evolution?
• What is it?
• When will it be here?
• Who will use it?
• Why will they use it?
• Where will they use it?
How big is this thing?
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4.
Cloud Enablement Report Card
Automation
Resource Pooling
Resource Visibility
Granularity of Control
Troubleshooting
Application Ecosystem
Vendor Independence
Compute Storage Network
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5.
Looking Back – Networking 2007
Access
Routing Mgmt
Control
VPNs … • Millions of lines of code
• 5,400 RFCs
Operating Systems & Middleware • High barrier to entry
• Billions of gates
Specialized Packet Handling/Forwarding Hardware • Huge complexity
• Power/people intensive
• Many complex functions embedded into the infrastructure
• OSPF, BGP, Multicast, NAT, TE, MPLS, Firewalls, …
• Redundant layers/services
• Unique “differentiation”
• Mainframe mentality industry
• Functionality  standards  hardware  nodes
Source: Adapted from ONS12 presentation by Brandon Heller, et al
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6.
Compounding the problem…
WAN • Evolved campus Ethernet
model into tree structure
• Core
Campus
• Aggregation
Core
• Access
• Most (95%) of traffic is
95% “north-south”
Aggregation • Segregated campus networks
Access at Access to avoid spanning
tree problems
5%
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7.
Compounding it further…
WAN • Applied same model to the
data center
• Different traffic patterns
Data Center
• Majority “east-west”
Core
• Different performance needs
• Lossless storage traffic
20% • Low latency, high bandwidth
Aggregation • Different service needs to
Access support virtual compute model
• Static to dynamic
• Multi-tenancy
• Workload management
80% by 2014(1)
Source: (1) Gartner Synergy Report
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8.
And even further…
• Significant gap exists
• Architectural
• Operational
• Organizational
• Assumption that physical fabric
is “up and running”
• YoYo mindset
• Extends to intra- and inter-data
center deployments
• Metro
• WAN
• Carrier
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9.
Additional market drivers
Video and Mobility are transforming business communications
Up to At least More than
10X 50 Billion 25%
Increase in network Devices will connect to Of all daily business
capacity to support new wireless networks by communications will be
wave of business video the year 2020 video or multi-media
applications communications by
UNIFIED WIRED
2013
INCREASE IN AND WIRELESS
CAMPUS COLLABORATION, T
BANDWIDTH
NETWORKS, IT RAINING, PRODUCT
REQUIREMENTS
CONSUMERIZATION IVITY
Source: Gartner – G00207476 Key Technology Analysis
Gartner – G00175764 Key Issues For Communications Strategies, 2010
ONS12
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10.
General shift in networking
FROM TO
Hardware/Appliances (Open) Software
Custom ASICs/FPGAs Merchant Silicon
(Logically) Centralized Control
Distributed Control Plane Plane
Protocols APIs
Policy-based Apps and
Function-Specific Features Services
Vendor-controlled Releases Rapid Innovation Cycles
Source: Adapted from ONS12 Presentation by Dan Pitt
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11.
Which leads us to SDN
ONF
In the SDN architecture, the
control and data planes are
SDN Model
decoupled, network
intelligence and state are
logically centralized, and the
underlying network
infrastructure is abstracted
from the applications.
Wikipedia
A network architecture in
which the network control
plane is decoupled from the
physical topology.
Source: ONF White Paper Software-Defined Networking: The New Norm for Networks – April 13, 2012
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12.
SDN theory and practice
The Premise… The Promise…
 Commodity (merchant silicon)  Centralized management and
solutions can be exploited control
 Control plane can be  More granular network control
distributed  Improved automation and
 State can be externalized management
 Acceptable performance can  Rapid innovation
be maintained  Programmability
 Standards will evolve  Increased network reliability
 Networking manufacturers will and security
adopt SDN-enabling protocols  Better end-user experience
and features
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13.
Essential elements of SDN
 Abstraction
 Pooling OpenStack CloudStack VMware
 Orchestration Nimbula et al
 Automation
 Service Insertion
 Apps
 Programmability (APIs)
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14.
Inside the layers
• Virtual network overlays
• Slicing
• Tenant-aware broadcast
• Application-aware path computation
• Traffic engineering
• Network services (FW, LB, Security)
• Data plane resource management
• Common services and libraries
• Topology
• Metadata
• State abstraction
• Packet forwarding
• Packet manipulation
• Statistics gathering
Source: Adapted from Dan Pitts, ONF
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15.
Typical use cases to date
 Multi-Tenancy
 Network Access Control
 Load Balancing
 Network Taps
 Cut-Through Applications
 Network Virtualization (overlays)
 Campus slicing
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16.
OpenFlow
OpenFlow SDN
(by itself)
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17.
OpenFlow
 A protocol specification
 Open Networking Foundation
 Requires OpenFlow-enabled devices
 Switches
 Defines controller messages
 PACKET_IN, PACKET_OUT, FLOW_REMOVED, etc.
 Enables construction of Flow Tables
 Match/Action
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18.
Analogy
Data Web Virtual Load
APP APP
Base Server Overlay Balancer
OS API Network OS API
Server Network Operating System
Operating System (SDN Controller)
CPU Instruction Set OpenFlow Instruction Set
and, or, xor, add, sub, mult, load, move… Match, Add, Modify, Translate, Forward, Drop
Server Hardware OpenFlow-enabled Device
Source: Adapted from IBM ONS12 presentation by Rakesh Saha, IBM & Amit Agarwal, Google
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19.
Simple OpenFlow-enabled Example
(
f View ) (
f View ) (
f View )
Control Control Control
Programs Programs Programs
Abstract Network View
Network Virtualization
Global Network View
Network OS
Packet
Forwarding
Packet
Forwarding
Packet
Packet Forwarding
Packet
Forwarding Forwarding
Source: Nick McKeown – Stanford University
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20.
Simple OpenFlow-enabled Example
(
f View ) firewall.c
(
f View
… ) f View ( )
Control if(Control
pkt->tcp->dport == 22) dropPacket(pkt);
Control
Programs Programs … Programs
Abstract Network View
Network Virtualization
Global Network View
Network OS
1. <Match, Action>
2. <Match, Action> 1. <Match, Action>
3. <Match, Action> 2. <Match, Action>
4. <Match, Action> 3. <Match, Action>
5. <Match, Action>
Packet 6. …
4. <Match, Action>
5. <Match, Action>
Forwarding 7. … 1. <Match, Action> 6. …
1. <Match, Action>
2. <Match, Action>
Packet 7. …
2. <Match, Action>
3. <Match, Action>
Forwarding
3. <Match, Action>
4. <Match, Action>
4. <Match, Action>
5. <Match, Action>
5. <Match, Action>
1. <Match, Action> 6. …
6. …
7. …
2. <Match, Action> Packet 7. …
3. <Match, Action>
Packet Packet 4. <Match, Action>Forwarding
5. <Match, Action>
Forwarding Forwarding…
6.
7. … Source: Nick McKeown – Stanford University
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21.
Flow Table Example
(
f View ) (
f View ) (
f View )
Control
Programs
Control
Programs
Control
Programs Flow Table
Abstract Network View
Network Virtualization
Generic primitive that sits on top
Global Network View
of (virtual) switch TCAM,
Network OS
designed to match well with
common ASICs
OpenFlow-enabled switch Example actions:
1. Switching and routing (port)
2. Firewall (drop)
3. Use with switch’s non-
OpenFlow logic (local)
4. Send to controller for
processing (controller)
Foundation network functions are
split between switch and high-
level decisions at the controller
Source: Adapted from ONS12 Presentation by Dan Pitt
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22.
Major OpenFlow (SDN) Controllers
Languag
Controller Platform(s) License Originator
e
Beacon Java Linux GPL Stanford University
Floodlight Java Linux GPL Big Switch (based on Beacon)
Windows, Mac, GPL (core), FOSS
Maestro Java Rice University
Linux, Android Licenses for your code
Python,
NOX Linux OpenFlow Stanford University
C++
Java,
OpenTransit Linux CPlane License CPlane (LAYERZngn)
Python
ProgrammableFlow
Ruby, C Linux (RHEL 6.1) GPL/NEC NEC (based on Trema)
Controller
Programmable Network
Ruby, C Linux (RHEL 6.1) GPL/IBM IBM (NEC OEM)
Controller
Open Network
Cisco
Environment (ONE)
Virtual Application
HP – Available 2H13
Networks SDN
(Rumored to be Big Switch)
Controller
NetScaler SDX Citrix – Early 2013
? Juniper Networks
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23.
OpenFlow-Enabled Switches
• Arista • IBM
• 7050 • IBM RackSwitch G8264
• Brocade • Juniper Networks
• MLX Series • MX Series
• NetIron XMR Series • Marvell
• NetIron CER 2000 Series • Prestera
• NetIron CES 2000 Series • NEC
• Cisco • PF5240
• Nexus 7000 Series • PF5280
• Dell • NoviFlow
• Force10 MXL 10/40GbE • NoviKit 100
• Extreme Networks • NETGEAR
• Black Diamond X Series • ProSafe Plus Series
• HP • Pica8
• 3500 Series • 3290, 3295, 3780, 3920
• 3800 Series • Pluribus Networks
• 5400 Series • F64 Series
• 8200 Series
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24.
Real-world “G-scale” OF example
Source: Google ONS12 presentation
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25.
Data Center/Cloud Networking Issues
 VLAN limits (4,094)
 Spanning Tree Protocol disabled links
 Reconfiguration to extend VLANs
 MAC address contention
 MAC address table size in ToR switches
 Layer 3 address contention
 Security “choke points”
 …
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26.
Virtual Overlays Using IP-encapsulation
Data Center A Data Center B
Hypervisor Hypervisor Hypervisor Hypervisor
VM VM VM VM VM VM VM VM
VIRTUAL OVERLAY
VIRTUAL OVERLAY
Overlay-enabled Overlay-enabled Overlay-enabled Overlay-enabled
Virtual Switch Virtual Switch Virtual Switch Virtual Switch
Physical Physical
Network Network
• “Similar” to other tunneling methods (L2TPV3, AToM, VPLS, LISP)
• Encapsulation via tunnel “endpoints”
• Not dependent on specific transports
• Layer 2 over Layer 3 (e.g., ECMP/OSPF)
• VMs see only Layer 2
• “Customer-edge”  easier to set up
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27.
Common IP-based Encapsulation Methods
Method Full Name Sponsors Approach
Distributed Overlay
DOVE Virtual Ethernet IBM Leverages OTV and VXLAN
Arista Networks,
Network Virtualization
Broadcom, Dell, 24-bit Virtual Subnet Identifier
NVGRE using Generic Routing
Emulex, HP, Intel, (VSI) in GRE header
Encapsulation
Microsoft
24-bit Overlay ID in OTV header
Overlay Transport
OTV Virtualization
Cisco inside UDP VLAN extension via
GRE/MPLS (Nexus 7000)
64-bit Context ID in STT header,
Stateless Transport
STT Nicira (VMware) “TCP-like” header, leverages
Tunneling
TSO/LRO
Arista Networks,
24-bit VXLAN Network Identifier
Virtual Extensible Local Broadcom, Cisco,
VXLAN (VNI) in VXLAN header inside
Area Network to destination endpoint identification
Citrix, Red Hat,
• Different approaches UDP packet
VMware
• Different approaches to load balancing for efficiency
• Can be negatively impacted by “middle boxes” (firewalls, intrusion protection, etc.)
• Some increased exposure to MAC-over-IP security threats
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28.
Encapsulation Headers
VXLAN NVGRE STT OTV*
Outer Ethernet Outer Ethernet Outer Ethernet Outer Ethernet
Header Header Header Header
Outer IP Header Outer IP Header Outer IP Header Outer IP Header
GRE Header TCP-Like Header UDP Header
UDP Header
Contains VSID (ACK/SEQ Fields) Contains OVERLAY ID
VXLAN Header Inner Ethernet STT Header Inner Ethernet
Contains VNI Header Contains Context ID Header
Inner Ethernet
Inner IP Header Payload Payload
Header
Payload Payload TCP-Like Header
Payload
TCP-Like Header
Payload
*As described in IETF Draft
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29.
But wait…
Service/ SDN needs to enable this
Application …and needs more than OpenFlow
and virtual overlays
FC Switch FC Switch
SAN SAN
Fiber
Ethernet Optical Optical Ethernet
V V V V Switch V V V V
Switch
M M M M M M M M
Hypervisor Hypervisor
Workload Migration
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30.
Still work to be done…
Data Plane Control Plane
 State of specifications  Scalability
 Maturity
 Changes across releases  Centralized vs distributed
 Silicon Concerns  State coherence between
 Specifications outpace silicon control and data plane
development
 Merchant silicon not optimized  Interoperability
for OF  SDN to non-SDN
 Performance
 Inter-Controller
 Scalability of Flow-Matches
(limited by TCAM size)  Multi-orchestrator conflicts
 Cost driver excludes rich multi-  Virtual overlays
core xPU ecosystem
Source: Adapted from ONS12 Presentation by Geng Lin - Dell
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31.
IEEE
Learning network… IETF
Clean Slate Standards ONF
ONRC Research
Big Switch
Networks
ON.LAB
CPlane
SDNCentral
Scott ConteXtream
ipSpace Shenker
Contrail Systems
Emerging
Nick SDN
Blogs
Martin McKeown Players Embrane
Casado
Midokura
Brad Cloud
Hedlund EtherealMind
Stuff Vyatta Nicira
(VMware)
Twilight in the Pluribus
Valley of the Networks NEC
OpenStack
Nerds
CloudStack Nimbula PLUMgrid
Routing-Bits
VMware
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32.
Resource Links
• Big Switch Networks: www.bigswitch.com
• Brad Hedlund: www.bradhedlund.com
• CloudStack: www.cloudstack.org
• ConteXtream: www.contextream.com
• Contrail Systems www.contrailsystems.com
• CPlane: www.cplane.net
• Embrane: www.embrane.com
• Ethereal Mind: www.etherealmind.com
• IEEE: www.ieee.org
• IETF: www.ietf.org
• ipSpace: www.ipspace.net
• Midokura: www.midokura.com
• NEC: www.necam.com/pflow
• Nicira: www.nicira.com Martin Nick Scott
• Nimbula: www.nimbula.com Casado McKeown Shenker
• ONRC: onrc.stanford.edu
• ON.LAB: onlab.us
• ONF: www.opennetworking.org
• OpenStack: www.openstack.org
• ONF: www.opennetworking.org
• PLUMgrid: www.plumgrid.com
• Pluribus Networks: www.pluribusnetworks.com
• Routing-Bits: www.routing-bits.com
• SDNCentral: www.sdncentral.com
• Stanford Clean Slate: cleanslate.stanford.edu
• Twilight in the Valley of the Nerds: nerdtwilight.wordpress.com
• VMware: www.vmware.com
• Vyatta: www.vyatta.com
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33.
Thank you!
Robert Keahey
robert.keahey@summalogic.com robert@cplane.net
www.summalogic.com www.cplane.net
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