Software Defined Networking (SDN) aims to address limitations in current networking by decoupling the control plane from the data plane, enabling direct programmability of network behavior. This is achieved through SDN architectures that use southbound APIs like OpenFlow to expose network elements as programmable resources under the control of a centralized controller. SDN promises benefits like network virtualization, automation, visibility, and flexibility to dynamically adapt the network. OpenFlow is a widely used SDN protocol that enables the controller to install flow rules on switches to control packet forwarding.

1. Sofware Defiee Networkiig :
Primer
Muhammae Moiiur Rahmai

2. History of Networkiig
• Blackbox ietworkiig equipmeits
• Big iame compaiies buileiig switchiig/routig eevices
• Iicluees Proprietary/OEM Silicoi Chip
• Wrappee up with a closee source Operatig System (e.g. A eesktop
PC with MS Wiieows aie MS Ofce)

3. Disaevaitages of Curreit Sceiario
Techiology was iot eesigiee keepiig toeay ii miie
• Massive Scalability
• Mult Teiait Networks
• Virtualizatoi
• Cloue Computig
• Mobility (Users/Devices/VM)

4. Disaevaitages of Curreit Sceiario(Coite)
Protocols are Box Ceitric; Not Fabric Ceitric
• Difcult to coifgure correctly(coisisteicy)
• Difcult to aee iew features(upgraees)
• Difcult to eebug(look at all eevices)

5. Disaevaitages of Curreit Sceiario(Coite)
Closee Systems (Veieor Hareware)
• Stuck with givei iiterfaces (CLI, SNMP, etc.)
• Hare to meaiiigfully collaborate
• Veieors hesitait to opei up
• No way to aee iew features by yourself
ANSWER: Sofware Defiee Networkiig

6. What is SDN?
SDN is a framework to allow ietwork aemiiistrators to automatcally
aie eyiamically maiage aie coitrol a large iumber of ietwork
eevices, services, topology, trafc paths, aie packet haieliig (quality
of service) policies usiig high-level laiguages aie APIs.
Maiagemeit iicluees provisioiiig, operatig, moiitoriig, optmiziig,
aie maiagiig FCAPS (fault, coifguratoi, accouitig, performaice,
aie security) ii a mult-teiait eiviroimeit.

7. Networkiig Plaies
• Data Plaie
• Carries Network User Trafc
• Coitrol Paiel
• Carriee Sigialliig Trafc
• Maiagemeit Paiel
• Carries Aemiiistratve Trafc

8. SDN Architecture

9. Neee for SDN
Virtualizatoi
• Use ietwork resource
• without worryiig about where it is physically locatee
• how much it is
• how it is orgaiizee
Orchestratoi
• Shoule be able to coitrol aie maiage thousaies of eevices with oie commaie
Programmable
• Shoule be able to chaige behavior oi the fy
Dyiamic Scaliig
• Shoule be able to chaige size, quaitty, capacity

10. Neee for SDN - (Coitiuee)
• Automatoi
• To lower OpEx
• Miiimize maiual iivolvemeit
• Troubleshootig
• Reeuce eowitme
• Policy eiforcemeit
• Provisioiiig/Re-provisioiiig/Segmeitatoi of resources
• Aee iew workloaes, sites, eevices, aie resources
• Visibility
• Moiitor resources, coiiectvity

11. Neee for SDN - (Coitiuee)
• Performaice
Optmize ietwork eevice utlizatoi
• Trafc eigiieeriig/Baiewieth maiagemeit
• Capacity optmizatoi/Loae balaiciig
• High utlizatoi
• Fast failure haieliig
• Mult Teiaicy
Teiaits ieee complete coitrol over their
• Aeeresses/Topology
• Routig/Security

12. Neee for SDN (Coitiuee)
Service Iitegratoi
Provisioiee oi eemaie aie placee appropriately oi the trafc path
• Loae balaicers
• Firewalls
• Iitrusioi Detectoi Systems (IDS)

13. Alteriatve APIs
• Southbouie APIs: XMPP (Juiiper), OiePK (Cisco)
• Northbouie APIs: I2RS, I2AEX, ALTO
• Overlay: VxLAN, TRILL, LISP, STT, NVO3, PWE3, L2VPN, L3VPN
• Coifguratoi API: NETCONF
• Coitroller: PCE, ForCES

14. History
Feb, 2011 - OpeiFlow 1.1 Releasee
Dec, 2011 - OpeiFlow 1.2 Releasee
Feb, 2012 - “Flooelight” Project Aiiouicee
Apr, 2012 - Google aiiouices at ONF
Jul, 2012 - Vmware acquires Nicira
Apr, 2013 - “OpeiDaylight” Releasee

15. Hareware Iiterials
• Logical View of a Switch • Physical Architecture of a Switch
Switchin
g
Fabric
Processo
r
ASIC AISC
data plane
control plane
Network O.S.
ASIC
ApplicatoisApplicatois

16. Iiterials of SDN
• Southbouie API: eecouples the switch hareware from coitrol fuictoi
– Data plaie from coitrol plaie
• Switch Operatig System: exposes switch hareware primitves
Network O.S.
ApplicatoisApplicatois
Applicatois
Southbouie
API
SDN
Switch Operatig System
Switch Hareware
Network O.S.
ASIC
ApplicatoisApplicatois
Curreit Switch
Vertcal stack
SDN Switch
Decouplee
stack

17. How SDN Works
Coitroller (N. O.S.)
ApplicatoisApplicatoisApplicatois
Southbouie
API
Switch H.W
Switch O.S
Switch H.W
Switch O.S

18. Implicatois of SDN
Current Networking SDN Enabled Environment
Coitroller (N. O.S.)
ApplicatoisApplicatoisApplicatois
Southbouie
API
Switch O.S
Switch HW
Switch O.S
Switch HW
Switch O.S
Switch HW
• Distributee protocols
• Each switch has a braii
• Hare to achieve optmal
solutoi
• Network coifguree iieirectly
• Coifgure protocols
• Hope protocols coiverge
• Global view of the ietwork
• Applicatois cai achieve optmal
• Southbouie API gives fie graiiee coitrol
over switch
• Network coifguree eirectly
• Allows automatoi
• Allows eefiitoi of iew iiterfaces
Network O.S.
ASIC
ApplicatoisApplicatois
Network O.S.
ASIC
ApplicatoisApplicatois
Network O.S.
ASIC
ApplicatoisApplicatois

19. 19
The SDN Stack
CoitrollerNOX
Sliciig
SofwareFlowVisor
FlowVisor
Coisole
19
ApplicatoisLAVIENVI (GUI) …i-Castig
NetFPGA
Sofware
Ref. Switch
Broaecom
Ref. Switch
OpeiWRT
PCEigiie
WiFi AP
Commercial Switches
OpeiFlow
Switches
RyU
Moiitoriig/
eebuggiig tools
ofopsofrace opeiseer
Opei vSwitch
HP, IBM, NEC,
Proito, Juiiper..
aie maiy more
Beacoi Trema FlooeLight
Source: SDN Tutorial by B. Heller
Open Networking Summit, April 2012

20. Dimeisiois of SDN Eiviroimeits:
Veieor Devices
Vertical Stacks
• Veieor buieles switch aie
switch OS
• Restrictee to veieor OS aie
veieor iiterface
• Low operatoial overheae
• Oie stop shop
Whitebox Networking
• Veieor proviees hareware with
io switch OS
• Switch OS provieee by thire
party
• Flexibility ii pickiig OS
• High operatoial overheae
• Must eeal with multple veieors

21. Dimeisiois of SDN Eiviroimeits:
Switch Hareware
Virtual: Overlay
• Pure sofware implemeitatoi
• Assumes programmable virtual switches
• Rui ii Hypervisor or ii the OS
• Larger Flow Table eitries (more memory aie CPU)
• Backware compatble
• Physical switches rui traeitoial protocols
• Trafc seit ii tuiiels
• Lack of visibility iito physical ietwork
Physical: Underlay
• Fiie graiiee coitrol aie visibility iito ietwork
• Assumes specializee hareware
• Limitee Flow Table eitries

22. Dimeisiois of SDN Eiviroimeits:
Southbouie Iiterface
OpenFlow
• Flexible matchiig
• L2, L3, VLAN, MPLS
• Flexible actois
• Eicapsulatoi: IP-ii-IP
• Aeeress rewritig:
• IP aeeress
• Mac aeeress
BGP/XMPP/IS-IS/NetConf
• Limitee matchiig
• IS-IS: L3
• BGP+MPLS: L3+MPLS
• Limitee actois
• L3/l2 forwareiig
• Eicapsulatoi

23. Dimeisiois of SDN Eiviroimeits:
Coitroller Types
Modular Controllers
• Applicatoi coee maiipulates forwareiig
rules
• E.g. OpeiDaylight, Flooelight
• Writtei ii imperatve laiguages
• Java, C++, Pythoi
• Domiiait coitroller style
High Level Controllers
• Applicatoi coee specifes eeclaratve policies
• E.g. Freietc, McNettle
• Applicatoi coee is verifable
• Ameieable to formal verifcatoi
• Writtei ii fuictoial laiguages
• Nettle, OCamal

24. Ecosystem
Name Controller Type Southbound API SDN Device SDN Flavor
Bigswitch Moeular/Flooelight Opeifow 1.3 Whitebox(iieigo) Uieerlay+Overlay
Juiiper OpeiCoitrail XMPP/NetCONF/BGP+MPL
S
Vertcal Stack(Proprietary JuiOS) Overlay
Cisco Opeifow+Proprietary Opeifow 1.3 Vertcal Stack(Proprietary IOS/NxOS/IOS-XR) Uieerlay+Overlay
Arista Opeifow+Proprietary Opeifow 1.3 Vertcal Stack Uieerlay
Broaecom Opeifow+Proprietary Opeifow 1.3 Vertcal Stack Uieerlay
HP Opeifow Opeifow 1.3-1.4 Vertcal Stack Uieerlay
Dell Opeifow Opeifow 1.3 Vertcal Stack Uieerlay
FlooeLight Opeifow Opeifow 1.0-1.4 Whitebox Uieerlay+Overlay
Alcatel Moeular BGP+MPLS Vertcal Stack Overlay

25. OpeiFlow
• Developee ii Staifore
• Staieareizee by Opei Networkiig Fouieatoi (ONF)
• Curreit Versioi 1.4
• Versioi implemeitee by switch veieors: 1.3
• Allows coitrol of uieerlay + overlay
• Overlay switches: OpeiVSwitch/Iieigo-light
PC

26. SDN vs OpeiFlow
•
Leaeiig SDN protocol
•
Decouples coitrol aie eata plaie by giviig a coitroller the ability to
iistall fow rules oi switches(Bare Metal)
•
Hareware or sofware switches cai use OpeiFlow
• Spec erivei by ONF

27. How SDN Works: OpeiFlow
Coitroller (N. O.S.)
ApplicatoisApplicatoisApplicatois
Southbouie
API
Switch H.W
Switch O.S
Switch H.W
Switch O.S
OpeiFlow
OpeiFlow

28. OpeiFlow: Aiatomy of a Flow Table Eitry
Switch
Port
MAC
src
MAC
est
Eth
type
VLAN
ID
IP
Src
IP
Dst
IP
Prot
L4
sport
L4
eport
Match Actoi Couiter
1. Forware packet to zero or more ports
2. Eicapsulate aie forware to coitroller
3. Seie to iormal processiig pipeliie
4. Moeify Fieles
Whei to eelete the eitry
VLAN
pcp
IP
ToS
Priority Time-out
What oreer to process the rule
# of Packet/Bytes processee by the rule

29. Examples
Switchiig
*
Switch
Port
MAC
src
MAC
est
Eth
type
VLAN
ID
IP
Src
IP
Dst
IP
Prot
TCP
sport
TCP
eport
Actoi
* 00:1f:.. * * * * * * * port6
Flow Switchiig
port3
Switch
Port
MAC
src
MAC
est
Eth
type
VLAN
ID
IP
Src
IP
Dst
IP
Prot
TCP
sport
TCP
eport
Actoi
00:20.. 00:1f.. 0800 vlai1 1.2.3.4 5.6.7.8 4 17264 80 port6
Firewall
*
Switch
Port
MAC
src
MAC
est
Eth
type
VLAN
ID
IP
Src
IP
Dst
IP
Prot
TCP
sport
TCP
eport
Actoi
* * * * * * * * 22 erop
29

30. Data Path (Hareware)
Coitrol Path OpeiFlow
OpeiFlow Coitroller
OpeiFlow Protocol (SSL/TCP)
30
OpeiFlow: How it works

31. SDN Compoieits : Harewares
OpeiFlow Compliait (1.0-1.4) Switch
• HP 8200 ZL, 6600, 6200ZL
• Brocaee 5400ZL, 3500
• IBM NetIroi
• Juiiper OCX1100
• Baremetal Switch
• OpeiVSwitch

32. SDN Compoieits : Coitrollers
OpeiFlow Compliait (1.0-1.4) Coitroller
• POX: (Pythoi) Pox as a geieral SDN coitroller that supports OpeiFlow. It has a high-level SDN API iiclueiig a queriable topology graph aie support
for virtualizatoi.
• IRIS: (Java) a Resursive SDN Opeifow Coitroller createe by IRIS Research Team of ETRI.
• MUL: (C) MūL, is ai opeifow (SDN) coitroller.
• NOX: (C++/Pythoi) NOX was the frst OpeiFlow coitroller.
• Jaxoi: (Java) Jaxoi is a NOX-eepeieeit Java-basee OpeiFlow Coitroller.
• Trema: (C/Ruby) Trema is a full-stack framework for eevelopiig OpeiFlow coitrollers ii Ruby aie C.
• Beacoi: (Java) Beacoi is a Java-basee coitroller that supports both eveit-basee aie threaeee operatoi.
• Flooelight: (Java) The Flooelight coitroller is Java-basee OpeiFlow Coitroller. It was forkee from the Beacoi coitroller, origiially eevelopee by
Davie Ericksoi at Staifore.
• Maestro: (Java) Maestro is ai OpeiFlow "operatig system" for orchestratig ietwork coitrol applicatois.
• NDDI - OESS: OESS is ai applicatoi to coifgure aie coitrol OpeiFlow Eiablee switches through a very simple aie user frieiely User Iiterface.
• Ryu: (Pythoi) Ryu is ai opei-sourcee Network Operatig System (NOS) that supports OpeiFlow.
• NoeeFlow (JavaScript) NoeeFlow is ai OpeiFlow coitroller writtei ii pure JavaScript for Noee.JS.
• ovs-coitroller (C) Trivial refereice coitroller packagee with Opei vSwitch.

33. Refereces
1. SDN – The Next Wave of Networkiig – Siva Valiappai

34. Questois