1. SDN – An IntroductionP. 1/15 13 February 2014
SDN – An Introduction
13 February 2014

2. SDN – An IntroductionP. 2/15 13 February 2014
Software-Defined Networking
An Introduction
Johan Schoofs – BELTUG Project Manager
johan.schoofs@beltug.be

3. SDN – An IntroductionP. 3/15 13 February 2014
Objective
Objective
Give you a barebones introduction to a new networking paradigm
that could shake up the way we think about networking
$ 1.26 billion!

4. SDN – An IntroductionP. 4/15 13 February 2014
Trends in ICT
Major Trends in ICT
Computing
Virtualisation
Cloud computing: broad network access, on-demand self-
service, resource pooling, measured service, rapid elasticity
Major impact!
Networking
Incremental upgrades to bandwidth
Same old protocols and mechanisms
Lack of real innovation and thus stagnation!
James Hamilton (Amazon Web Services) in 2010: Data center
networks are in my way!

5. SDN – An IntroductionP. 5/15 13 February 2014
Industry Response
A Late but Swelling Response from the Networking Industry
Wanted: more flexibility and ease of use/management!
Innovation through software-defined networking (SDN)
Potential business benefits are linked to:
Centralised control
Programmability
Orchestration
Virtualisation
Remove the network as the limiting factor for virtualisation and cloud
services

6. SDN – An IntroductionP. 6/15 13 February 2014
Centralised Control
Business Benefit 1: Centralised Control
Without SDN: data and control plane integrated in forwarders
(switch/router)
F1
F2
F4
F3
Control
Data

7. SDN – An IntroductionP. 7/15 13 February 2014
Centralised Control
Business Benefit 1: Centralised Control
With SDN: data plane in forwarder, control plane in logically
centralised controller
F1
F2
F4
F3
Controller

8. SDN – An IntroductionP. 8/15 13 February 2014
Centralised Control
Business Benefit 1: Centralised Control
An omniscient central controller
It knows were the hosts are
It known what the network topology looks like
It programs the forwarding state of the forwarders
Examples:
Create a logical test network that runs on the same physical
network that runs the production network
Enforce policies on dynamically learned traffic flows to
maintain QoS
Real least cost routing based on the financial cost
Intelligent network security shunting particular flows
Traffic mirroring for logging, reporting or analysis

9. SDN – An IntroductionP. 9/15 13 February 2014
Programmability
Business Benefit 2: Programmability
Traditional network configuration is:
Done with a CLI (scripts) or GUI interface
Time-consuming, error-prone, tedious
SNMP: too limited, where are the tools?
Needed: full APIs that allow the use of powerful tools
SDN delivers!
Examples:
Much richer scripts that allow for automated provisioning
Orchestration tools to support the introduction of new business
applications

10. SDN – An IntroductionP. 10/15 13 February 2014
Programmability
Business Benefit 2: Programmability
Anything available yet?
Custom APIs:
Cisco’s onePK, Juniper’s Juno, …
Open APIs:
OpenFlow (see the Open Networking Foundation)
Supported by many switch vendor such as Alcatel-Lucent,
HP, Juniper, Cisco, Big Switch Networks, Brocade
Communications, NEC, Dell, IBM,…
Open-source OpenFlow controllers: Floodlight, MUL, NOX,…

11. SDN – An IntroductionP. 11/15 13 February 2014
Orchestration
Business Benefit 3: Orchestration
Provisioning the network in a coordinated/automated way with
servers, storage and applications
Goals: quicker, large scale and less errors in network provisioning
Available tools mainly aimed at cloud service providers now: rapid
provisioning of multi-tenant logical networks spanning multiple
datacentres
The long view: network provisioning integrated with broader IT
orchestration will be the norm for all networks in the future

12. SDN – An IntroductionP. 12/15 13 February 2014
Virtualisation
Business Benefit 4: Virtualisation
Let’s virtualise the network like we have successfully virtualised the
server and storage!
This is not completely new: VLANs + Q-in-Q tunnels, MPLS but mainly
service provider oriented, not datacentre oriented
Allows for the creation of overlays: the new virtual network without
the limitations of IEEE VLANs
But: the SDN controller will allow you to deploy and maintain the
virtual networks in an easy manageable way

13. SDN – An IntroductionP. 13/15 13 February 2014
NFV
Network Functions Virtualisation

14. SDN – An IntroductionP. 14/15 13 February 2014
Bleeding Edge Technology?
Caveats:
Keep the following in mind:
SDN is an overloaded term
This technology is young and evolving fast
Not yet fully mature
But already in use by Amazon, Google, Microsoft, RackSpace,…
Open standards are being worked out by the IETF
A project to watch: OpenDaylight
“At this early stage of SDN and NFV adoption, the industry acknowledges the
benefits of establishing an open, reference framework for programmability and
control through an open source SDN and NFV solution. Such a framework
maintains the flexibility and choice to allow organizations to deploy SDN and
NFV as they please, yet still mitigates many of the risks of adopting early stage
technologies and integrating with existing infrastructure investments.”

15. SDN – An IntroductionP. 15/15 13 February 2014
Thanks for Your Attention!