3. Software-Defined Networking
• Emerging Definition:
– “Software programmabiity of networks”
• OpenFlow protocal from Open Networking Foundation
(ONF)
– Separation of switches and routers from
hardware, allowing programming by a controller
• Architectural Definition
– Separation of network control and network
forwarding planes
4. SDN Architecture
• CONTROL / Management PLANE
– SDN controller APIs <NORTH>
• NETWORK FORWARDING PLANE
– Switching <SOUTH>
5. SDN Protocols : Implementation
• Protocols
– OpenFlow (ONF)
– Extensible Messaging and Presence Protocol (XMPP)
– Network Configuration Protocol (Netcong)
– OpenStack® (Rackspace and NASA)
• Implementation:
– OpenFlow protocol is used to program the forwarding behavior
of the switch.
– The controller provides management plane functionality such as
performance and fault management via SNMP and other
standard protocols, and it typically handles configuration
management of OpenFlow compliant devices in order to
provide network topology, forwarding, QoS, and link
management. 1
6. Switch Hardware
• Integration into current technology
– Layer2/3 switches can be converted to be OpenFlow-
hybrid switches by integrating OpenFlow agent in
firmware supported by the native switch Network
Operating System (NOS).
• Cisco – allows export of OpenFlow vs programmability of the
switch.
– Simplest – monitoring – export OpenFlow for
documentation of network
– Network Virtualization Platform (NVP) deployed in
virtualization environment.
• Nicira bought by VMWare.
7. Controller – NOS Deployment
• OpenFlow Proof-of-Concept
– Floodlight – Open-SDN controller
• Java-based OpenFlow-spec controller
– OpenVSwitch – virtual switching
– Setup:
http://networkstatic.net/openflow-openvswitch-lab
• Control – change > hi-speed
– Virtualization – integrated w/ hypervisor
– OpenFlow – hi-load vs Sflow fasterr monitor for hybrid
controller providing faster feedback of load across network
• Monitoring – evaluation
– Installing Wireshark On Linux for OpenFlow Packet
Captures, February 3, 2013
http://networkstatic.net/installing-wireshark-on-linux-for-openflow-packet-
captures/
10. References
1. What is software defined networking (SDN)?
http://www.networkworld.com/news/2012/082912-insider-sdn-262010.html
2. Install - RHEL – Open Vswitch Install (CentOS information), Dec 1
2012, Brent Salisbury
http://networkstatic.net/open-vswitch-red-hat-installation/
3. Cisco tries to head off software-defined networks, Jim Duffy,
Network World, April 19, 2012 10:20 AM ET
http://www.networkworld.com/news/2012/041912-cisco-sdn-258457.html
4. Floodlight – OpenFlow Controller
http://floodlight.openflowhub.org
5. OpenFlow & Sflow –
http://blog.sflow.com/2011/05/openflow-and-sflow.html
6. Setting up NetFlow on vSphere distributed switch, By Tomi Hakala,
February 1st, 2012, NetFlow analysis - monitoring
http://v-reality.info/2012/02/setting-up-netflow-on-vsphere-distributed-switch/
11. Tutorial/Course
• Tutorial :
Installing Wireshark On Linux for OpenFlow Packet
Captures, February 3, 2013
http://networkstatic.net/installing-wireshark-on-linux-for-openflow-
packet-captures/
• Free online course: All you ever wanted to know about
SDN – Ga Tech MOOC (massive open online course)
– http://www.itworld.com/hardware/344738/free-online-
course-all-you-ever-wanted-know-about-sdn
– Begins: May 27th
– Workload: 6-8 hours of work per week.
– Prerequisites: Python; basic networking course.
12. SDN : OSI Layer 4-7 Network Services
• Layer 4 through Layer 7 are services are delivered by the upper layers of the Open Systems
Interconnection (OSI) communication model. Layer 4-7 services, sometimes referred to as the upper
layers, support end-to-end communication between a source and destination application and are used
whenever a message passes from or to a user.
• Providing Layer 4-7 services involves sitting somewhere in the middle of the network delivery path and
using that vantage point to apply new services without requiring change to applications on either end. The
list of possible Layer 4-7 services is effectively infinite in a cloud computing or software-defined
networking (SDN) infrastructure because they can be built in the upper layers of the OSI model, largely
independent of the underlying network. For example, SDN can change Layer 4-7 network services by
enabling virtual applications of load balancing, WAN acceleration and virtual security appliances.
Ref: http://whatis.techtarget.com/definition/Layer-4-7-Layer-4-through-Layer-7-services
• Layer 4,
– the Transport Layer, ensures end-to-end delivery of messages for both "connection-mode" data such as TCP
connections and "connectionless-mode" data such as UDP datagrams. For both modes, the endpoints of
communication are identified by port numbers such as TCP port 80 or UDP port 161.
• Layer 5,
– the Session Layer, provides services for coordinating communication between applications and
synchronizing message delivery. For example, a protocol with suspend/resume or checkpoint/rollback
capabilities includes session layer services such as ITU X.225, AppleTalk or RPC.
• Layer 6,
– the Presentation Layer, provides services for converting data from local format (abstract syntax) into a
machine-independent format (transfer syntax). Many application protocols are defined in Abstract Syntax
Notation One (ASN.1) notation. ASN.1 defines a set of data structures mapped to encoding rules – for
example, how an Integer should be encoded into a bit string to be transmitted to and decoded by a recipient
using XML Encoding Rules (XER).
• Layer 7,
– the Application Layer provides common services used by applications to establish, release and abort
communication with each other, as well as specific services. Most applications “live” at Layer 7, including the
File Transfer Protocol (FTP), the Simple Mail Transfer Protocol (SMTP), the Post Office Protocol (POP), the
Hyper Text Transfer Protocol (HTTP) and the Domain Name System Protocol (DNS).
13. Revision Updates
• 5/20/2013 : Add OSI northbound – related L4-
7 services information. Referenced by SDN
application (software-defined networking
application) [techtarget search]
• 7/18/2013 : Add SDN controller from
OpenDaylight Project.
