Software Defined Networking: tecnologia e prospettive Prof. Stefano Salsano...

Software Defined Networking:tecnologia e prospettive

Prof. Stefano [email protected]

Seminario nel corso “Advanced Networking and Internet Modeling„ Prof. Francesco Lo Presti

26 Maggio 2015

Outline

SDN motivations: Internet ossification, network complexity, barriers to innovationSDN approach, goals and dreams…A bit of technology: OpenFlowApplication examples

SDN and cloudGoogle’s SDN WANSDN and Network Function Virtualization

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3

Internet success

• The Internet success is a remarkable story, from a research infrastructure to a global network, interconnecting billions of devices and people

• Innovation looks easy on the Internet as we witness always new and more powerful services and applications– Web, P2P, VoIP, social networks, video streaming…

Network ossification

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• The history is a bit different behind the scene:

–Huge complexity –Few people can innovate–Closed equipment–Network «ossification»

4

Specialized Packet Forwarding Hardware

Feature Feature





OperatingSystem

OperatingSystem

OperatingSystem

OperatingSystem

OperatingSystem

Feature Feature

Feature Feature

Feature Feature

Feature Feature

Classical network architecture

• Distributed control plane• Distributed routing protocols: OSPF, IS-IS, BGP, etc.

5

Million of linesof source code

5400 RFCs Barrier to entry

Billions of gates Complex Power Hungry

Closed, vertically integrated, boated, complex, proprietaryMany complex functions baked into the infrastructure

OSPF, BGP, multicast, differentiated services,Traffic Engineering, NAT, firewalls, MPLS, redundant layers, …Little ability for non-telco network operators to get what they wantFunctionality defined by standards, put in hardware, deployed on nodes

The Networking Industry (2010s)


OperatingSystem

Feature Feature

Routing, management, mobility management, access control, VPNs, …

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Outline



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Feature Feature

Network OS

Well-defined open API Constructs a logical mapof the network

Software Defined Network

OpenFlow

Simple PacketForwarding Hardware





Open, vendor-agnostic protocol Southbound

Northbound

17/09/2013 8

Microprocessor

Mainframe industry in the 1980s: Vertically integrated

Closed, proprietarySlow innovationSmall industry

SpecializedOperating

System

SpecializedHardware

AppAppAppAppAppAppAppAppAppAppAppSpecialized

Applications

HorizontalOpen interfacesRapid innovation

Huge industry

Linux MacOS

Windows(OS) or or

Analogy with IT industry:from mainframes to PCs

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Networking industry in 2010s: Vertically

integratedClosed, proprietary

Slow innovation

AppAppAppAppAppAppAppAppAppAppApp

HorizontalOpen interfacesRapid innovation

ControlPlane

ControlPlane or or

SpecializedControlPlane

SpecializedHardware

SpecializedFeatures

MerchantSwitching Chips

Analogy with IT industry:from closed box to SDN

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ControlPlane

SDN Concept

• Separate Control plane and Data plane entities– Network intelligence and state are logically centralized– The underlying network infrastructure is abstracted from the

applications• Execute or run Control plane software on general purpose

hardware– Decouple from specific networking hardware– Use commodity servers

• Have programmable data planes– Maintain, control and program data plane state from a central

entity• An architecture to control not just a networking device

but an entire network

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Network OS and OpenFlow

• Network OS– Distributed system that creates a consistent, up-to-date

network view, runs on servers (controllers) in the network– Uses an open protocol to:

• Get state information from forwarding elements• Give control directives to forwarding elements

• OpenFlow– is a protocol for remotely controlling the forwarding table of

a switch or router– is one element of SDN

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Abstractions in the Control Plane

Routing Traffic Engineering

Other Applications

Well-defined API

Network Map Abstraction

Forwarding

Forwarding

Forwarding

Forwarding

Separation of Data and Control Plane

Network Virtualization

Network Operating System or “Controller”

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Forwarding Abstractions

• Purpose: Abstract away forwarding hardware• Flexible

– Behavior specified by control plane– Built from basic set of forwarding primitives

• Minimal– Streamlined for speed and low-power– Control program not vendor-specific

OpenFlow is an example of such an abstraction

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SDN promises (or dreams…)

• Innovation– beyond IP, clean slate approaches…

• Change of paradigm«Redefining Abstractions» (see Scott Shenker presentation)

• Openness– open fast switching hardware, open controllers

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Outline



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Traditional network node: Switch

• Typical Networking Software– Management plane– Control Plane – The brain/decision maker– Data Plane – Packet forwarder

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Traditional network node: Router

• Router can be partitioned into control and data plane– Management plane/ configuration – Control plane / Decision: OSPF (Open Shortest Path First)– Data plane / Forwarding

Adjacent Router RouterManagement/Policy plane

Configuration / CLI / GUI

Static routesControl planeOSPF

Neighbor table

Link state database

IP routing table

Forwarding tableData planeData plane

Control planeOSPF

Adjacent Router

Data plane

Control planeOSPF

Routing

Switching

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Data Path (Hardware)

Control Path OpenFlow

OpenFlow Controller

OpenFlow Protocol (SSL/TCP)

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OpenFlow Basics

OpenFlow Protocol

Data Path (Hardware)

Control Path OpenFlowEthernet Switch

Network OS

Control Program A Control Program B

OpenFlow Basics

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Control Program A Control Program B

Network OS

OpenFlow Basics

PacketForwarding

PacketForwarding

PacketForwarding

FlowTable(s)

FlowTable(s)

“If header = p, send to port 4”

“If header = ?, send to me”

“If header = q, overwrite header with r, add header s, and send to ports 5,6”

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OpenFlow Primitives

• Match arbitrary bits in headers:

– Match on any header, or new header– Allows any flow granularity

• Action– Forward to port(s), drop, send to controller– Overwrite header with mask, push or pop– Forward at specific bit-rate

•

HeaderHeader DataData

Match: 1000x01xx0101001x

<Match, Action>

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General Forwarding Abstraction

Small set of primitives“Forwarding instruction set”

Small set of primitives“Forwarding instruction set”

Protocol independentBackward compatibleProtocol independentBackward compatible

Switches, routers, WiFi APs, basestations, TDM/WDM

Switches, routers, WiFi APs, basestations, TDM/WDM

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Controller

PC

HardwareLayer

SoftwareLayer

Flow Table

MACsrc

MACdst

IPSrc

IPDst

TCPsport

TCPdport Action

OpenFlow Client

**5.6.7.8*** port 1

port 4port 3port 2port 1

1.2.3.45.6.7.8

OpenFlow example

OpenFlow Basics Flow Table Entries

SwitchPort

MACsrc

MACdst

Ethtype

VLANID

IPSrc

IPDst

IPProt

L4sport

L4dport

Rule Action Stats

1. Forward packet to zero or more ports2. Encapsulate and forward to controller3. Send to normal processing pipeline4. Modify Fields5. Any extensions you add!

+ mask what fields to match

Packet + byte counters

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VLANpcp

IPToS

Examples

Switching

*

SwitchPort

MACsrc

MACdst

Ethtype

VLANID

IPSrc

IPDst

IPProt

TCPsport

TCPdport Action

* 00:1f:.. * * * * * * * port6

Flow Switching

port3

SwitchPort

MACsrc

MACdst

Ethtype

VLANID

IPSrc

IPDst

IPProt

TCPsport

TCPdport Action

00:20.. 00:1f.. 0800 vlan1 1.2.3.4 5.6.7.8 4 17264 80 port6

Firewall

*

SwitchPort

MACsrc

MACdst

Ethtype

VLANID

IPSrc

IPDst

IPProt

TCPsport

TCPdport Action

* * * * * * * * 22 drop

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Reactive vs. Proactive (pre-populated)

Reactive

• First packet of flow triggers controller to insert flow entries

• Efficient use of flow table• Every flow incurs small

additional flow setup time• If control connection lost,

switch has limited utility• Extremely simple fault

recovery

Proactive

• Controller pre-populates flow table in switch

• Zero additional flow setup time

• Loss of control connection does not disrupt traffic

• Essentially requires aggregated (wildcard) rules

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Microflow vs. Aggregated

Microflow

• Every flow is individually set up by controller

• Exact-match flow entries• Flow table contains one

entry per flow

• Good for fine grain control, policy, and monitoring, e.g. campus

Aggregated

• One flow entry covers large groups of flows

• Wildcard flow entries• Flow table contains one

entry per category of flows

• Good for large number of flows, e.g. backbone

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Windows(OS)

Windows(OS)

Linux MacOS

x86(Computer)

Windows(OS)

AppApp

LinuxLinuxMacOS

MacOS

Virtualization layer

App

Controller 1

AppApp

Controller2

Virtualization or “Slicing”

App

OpenFlow

Controller 1NOX(Network OS)

Controller2Network OS

Virtualization trend

Computer Industry Network Industry

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Simple Packet Forwarding Hardware

Network Operating System 1

Open interface to hardware

Virtualization or “Slicing” Layer




App App App App App App App App

Many operating systems, orMany versions

Open interface to hardware

Isolated “slices”





17/09/2013 30

Outline



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SDN and cloud

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x 10000…“multi-tenant”multi site

Cloud

SDN and cloud

• Cloud computing service providers face the issue of multi-tenancy at the network level

• IP and Ethernet each have virtual network capability, but limited in terms of – how many tenants can be supported– how isolated each tenant– configuration and management complexity

• SDN is increasingly accepted as the path to "cloud networking"

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Neutron service in the OpenStack cloud architecture (was Quantum)

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Nova ComputeService

Virtual Machines

SwiftStorageService

Object Store

Basic Network Connectivity

Nova, Swift, and Neutrum API

Servers Disks

Developers have ability to create multiple networks for their own purposes (multi-tier apps)

May support provisioning of both virtual and physical networks – differences captured through plugin’s

NeutrumService

Virtual Networks

Networks

Neutrum service in the OpenStack cloud architecture

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Compute Service(Nova)

Network Service

(Neutrum)

Tenant API

Internal API Admin API SystemAdmin

Plug-In

User Application – CLI - Horizon Dashboard - Tools

Tenant API

Compute NodeHypervisor

vSwitch

PhysicalNetwork

Router/Switch

Clustered Network

Controller

Available Neutrum plug-ins

• Open vSwitch• Linux bridge• Nicira NVP• Cisco (Nexus switches and UCS VM-FEX)

– WIP: VXLAN• NTT Labs Ryu OpenFlow controller • NEC OpenFlow• Big Switch Floodlight

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Most of them are SDN based !

The zoo of network technologies

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Data center simplification

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Traditional Network

Fabric

Network Fabric Defined

• Flat network• Every port virtually connected to every other • High speed network; 10 Gig-E, roadmap to 40 Gig-E and

100 Gig-E • Operationally simple • Optimized for virtual traffic and east west traffic flows• Optimized packet processing

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The shift toward SDNs

• Allows for the network to be in better alignment with the current data center trends

• Brings a high level of agility to the network

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• Enables programmability • Improves application

performance • Abstracts the control layer

from the network infrastructure lay

• Complements fabrics • Creates scalable network

virtualization

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Outline



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Google’s B4: an SDN success story

• In April 2012 Google presented their OpenFlow based WAN (“B4”), globally interconnecting the Data Centers

• B4 is based on a SDN architecture using OpenFlow to control relatively simple switches built from merchant silicon

• Google engineered the switches and the SDN architecture

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B4 worldwide deployment (2011)

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Typical WAN engineering rules

• WAN links are typically provisioned to 30-40% average utilization. This can mask virtually all link or router failures from clients.

• Such overprovisioning give reliability at the costs of 2-3x bandwidth over-provisioning and high-end routing gear.

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Google’s Requirements

• Google fully controls applications and server using the WAN

• The most bandwidth intensive applications are large-scale data copies: they can adapt to available capacity

• The number of data center is limited, making centralized bandwidth control feasible

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Traffic Engineering

• Using SDN, B4 simultaneously supports standard routing protocols and centralized TE

• TE algorithms allow to:– adjudicate among competing demands during

resource constraint– use multipath forwarding/tunneling– dynamically reallocate bandwidth in the face of

link/switch failures• Many B4 links to run at near 100% utilization

and all links to average 70% utilization

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The SDN switches

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SDN based WAN architecture

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Performance measurements

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link utilization

low prio loss

high prio loss

ratiohigh prio /low prio

…and if you are not Google ?

A truly open SDN eco-system will grow, including controllers/network OS, management tools, switching equipment, and “network applications” (e.g. a TE component)

Vendors will include SDN concepts in their solutions, mostly in a proprietary way

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?

«SDN washing»

• All main networking equipment vendors are now offering their SDN products and solutions

• “SDN washing” – when networking vendors essentially take their existing technologies and try to re-label them as SDN products

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OpenDayLight

• Cisco, Juniper, Ericsson, IBM, NEC and other network vendors are joining up to standardize SDN (April 2013) with OpenDayLight project

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OpenDayLight

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Outline



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SDN and NFV(Network Function Virtualization)

• NVF: a Network-operator-driven specification group within ETSI.

• Initiated by 13 carriers now grown to 23 members

http://portal.etsi.org/portal/server.pt/community/NFV/367

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http://www.google.de/imgres?imgurl=http://www.childflight.org.au/images/images/Blue-Telstra-Logo.gif&imgrefurl=http://www.childflight.org.au/home.html&h=325&w=285&sz=4&tbnid=YVyhnpUkgKbUQM:&tbnh=86&tbnw=75&prev=/search?q=telstra+logo&tbm=isch&tbo=u&zoom=1&q=telstra+logo&usg=__b-x-IjUvuexS-f6RfWqE4DsVU6g=&hl=de&sa=X&ei=Nt9yUPGQG7DZ4QTz-IDQDw&ved=0CC8Q9QEwBg







IndependentSoftware Vendors

BRAS

Firewall

DPI

CDN

Tester/QoEmonitor

WANAcceleration

MessageRouter

Radio NetworkController

CarrierGrade NAT

Session BorderController

Classical Network ApplianceApproach

PE Router

SGSN/GGSN

Generic High VolumeEthernet Switches

Generic High Volume Servers

Generic High Volume Storage

Orchestrated,automatic remote install

Network Functions VirtualisationApproach

hypervisors

SDN and NFV(Network Function Virtualization)

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NFV and SDN are complementary

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Open Innovation

NetworkFunctions

Virtualisation

Software Defined

Networks

Creates operational flexibilityReduces ReducesCapEx, OpEx, space & power delivery time consumption

Createscontrol

abstractions to foster innovation.

Createscompetitivesupply of innovative applications by third parties

Outline



Final remarks17/09/2013 58

The two paths to SDN (r)evolution

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• New Abstractions / high level modeling of networks• Disruptive low cost net architectures and open hardware• Open Source Software (for Carriers’ Class nodes) • Open Innovation

Evolutionary path : progressive innovation

Revolutionary path : disruptive innovation

• Seamless integration in current networks, compatibility with legacy • Solutions from traditional Vendors (or even Start-ups) … • Costs Reductions (CAPEX, OPEX)

Thank you for your attention !

Stefano Salsano, Ph. D.Associate Professor

e-mail: [email protected]://netgroup.uniroma2.it/Stefano_Salsano/

Phone: +39 06 7259 7770Fax: +39 06 7259 7435

UNIVERSITY OF ROME “TOR VERGATA”Department of Electronics Engineering

Via del Politecnico, 1 - 00133 Rome - Italy

Questions ?

Suggested Readings

– A. Manzalini, V. Vercellone, M. Ullio, «Software Defined Networking: sfide ed opportunità per le reti del futuro», Notiziario Tecnico Telecom Italia, n.1/2003http://www.telecomitalia.com/content/dam/telecomitalia/it/archivio/documenti/Innovazione/NotiziarioTecnico/2013/n1-2013/NT1-4-2013.pdf

– N. McKeown et al. «OpenFlow: Enabling Innovation in Campus Networks», CCR 2008http://www.openflow.org/documents/openflow-wp-latest.pdf

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http://www.telecomitalia.com/content/dam/telecomitalia/it/archivio/documenti/Innovazione/NotiziarioTecnico/2013/n1-2013/NT1-4-2013.pdf




http://www.openflow.org/documents/openflow-wp-latest.pdf

http://www.openflow.org/documents/openflow-wp-latest.pdf

Main sources

– Jennifer Rexford “Enabling Innovation Inside the Network”– Scott Shenker with Martín Casado, Teemu Koponen, Nick

McKeown and others “The Future of Networking, and the Past of Protocols”

– Rob Sherwood (with help from many others) “An Experimenter’s Guide to OpenFlow” - GENI Engineering Workshop June 2010

– Brandon Heller, Rob Sherwood, David Erickson, Hideyuki Shimonishi, Srini Seetharaman, Murphy McCauley, “Tutorial 1: SDN for Engineers”

– Dan Pitt, “The Open Networking Foundation: OpenFlow & SDN from lab to market”

– Yeh-Ching Chung, “Network Virtualization - Software Defined Network”

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Main sources

– Tom Nolle “The role of software-defined networks in cloud computing”

– Lew Tucker, “Quantum: What it is and Where it’s going”– Zeus Kerravala, “The Time for ICT is Now”– Tom Nollle “Understanding the relationship between SDN and

NFV”– Bob Briscoe (+ Don Clarke, Pete Willis, Andy Reid, Paul Veitch),

“Network Functions Virtualisation”– Antonio Manzalini, “Software Will Eat the Networks – Welcome

to the Blue SDN”

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My work on SDN

– OSHI Open Source Hybrid IP/SDN networking http://netgroup.uniroma2.it/OSHI/– The DREAMER project http://netgroup.uniroma2.it/DREAMER/ – S. Salsano, P. L. Ventre, F. Lombardo, G. Siracusano, M. Gerola, E. Salvadori, M. Santuari,

M. Campanella, L. Prete “OSHI - Open Source Hybrid IP/SDN networking and Mantoo - a set of management tools for controlling SDN/NFV experiments”, submitted paper (May 2015)

– S. Salsano, P. L. Ventre, L. Prete, G. Siracusano, M. Gerola, E. Salvadori,“Open Source Hybrid IP/SDN networking (and its emulation on Mininet and on distributed SDN testbeds)”, 3rd European Workshop on Software Defined Networks, EWSDN 2014, 1-3 September 2014, Budapest, Hungary

– M. Gerola, M. Santuari, E. Salvadori, S. Salsano, P. L. Ventre, M. Campanella, F. Lombardo, G. Siracusano, “ICONA: Inter Cluster ONOS Network Application”, demo paper, 1st IEEE Conference on Network Softwarization (Netsoft 2015), London, UK, 13-17 April 2015

– N. Blefari-Melazzi, A. Detti, G. Morabito, S. Salsano, L. Veltri, “Information Centric Networking over SDN and OpenFlow: Architectural Aspects and Experiments on the OFELIA Testbed”, to appear in Elsevier Computer Networks, Special Issue on Information-Centric Networking (ICN), 2013

– N. Blefari-Melazzi, A. Detti, G. Mazza, G. Morabito, S. Salsano, L. Veltri, “An OpenFlow-based Testbed for Information Centric Networking”, Future Network & Mobile Summit 2012, 4-6 July 2012, Berlin, Germany

– L. Veltri, G. Morabito, S. Salsano, N. Blefari-Melazzi, A. Detti, “Supporting Information-Centric Functionality in Software Defined Networks”, SDN’12: Workshop on Software Defined Networks, Co-located with the IEEE International Conference on Communications (ICC), June 10-15 2012, Ottawa, Canada

– A. Detti , C. Pisa, S. Salsano, N. Blefari-Melazzi, “Wireless Mesh Software Defined Networks (wmSDN)”, The 2nd International Workshop on Community Networks and Bottom-up-Broadband (CNBuB 2013), Lyon, France, October 7th, 2013

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http://netgroup.uniroma2.it/OSHI/

http://netgroup.uniroma2.it/DREAMER/

Software Defined Networking: tecnologia e prospettive Prof. Stefano Salsano...

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