Software Defined Networking

Kathryn Abbett

Definition

□Origins from Berkley and Stanford, around 2008

□Software-Defined Networking (SDNs) allows applications to realize necessary tasks for network management

□Routing□Traffic control□Load balancing

Methodology

□SDNs converse with and directly manipulate control software

□Installs packet-processing rules onto switches

□This allows direct control of the network and flexibility for fine-tuning

General Architecture

Architecture Explained

□ There is no set architecture for SDNs because each is tailored to the network it modifies

□ There are certain consistencies involved□ Guarantee that the design and implementation of SDN devices conforms to the

standards, correctness and safety properties□ Check consistency and safety of their network configurations and virtual and

physical topologies to prevent loops in the network, unintentional isolation, seamless updates

□ These consistencies will keep the network running smoothly and allow administrators to focus on other properties of the network

Models

□Network Virtualization□Eliminates partitioning issue from VLAN and

allows for more scalability□Can manage multi-tenant clouds without

modifying the network itself□Virtual network can only connect to virtual

machines□Network devices only see traffic and cannot

prioritize certain virtual networks

Models

□Evolutionary Model□Enhances current networking software

without expanding□Typically partition network into

neighborhoods to control traffic□Still scalable in theory, so long as the

machines all abide by standards□Not easily integrated with other SDNs or

between Cloud and user services

Models

□OpenFlow Model□Most commonly associated with SDN□Central programmer creates each device’s

forwarding table□Extremely flexible, puts network at

programmer’s fingertips□Basis for all of SDN’s initial creation□Still lack of detail and agreement on

structure and components

Optimal Utilization

□There is no “one best” model□Most networks require an overlay of

two or even all three models□OpenFlow nearly universal□Large-scale will require network

virtualization due to infinite scalability□Evolutionary aids in reducing

redundancy

References

□ Composing Software-Defined Networks, Christopher Monsanto∗, Joshua Reich∗, Nate Foster†, Jennifer Rexford∗, David Walker∗, ∗Princeton †Cornellhttps://www.usenix.org/system/files/conference/nsdi13/nsdi13-final232.pdf

□ Software Driven Networks Problem Statement, T. Nandeau, Sept 30 2011http://tools.ietf.org/html/draft-nadeau-sdn-problem-statement-00

□ Formal Specification Framework for Software-Defined Networks (SDN), Shin et al.http://tools.ietf.org/html/draft-shin-sdn-formal-specification-03

□ Three models of SDN explained, Tom Noellehttp://searchcloudprovider.techtarget.com/tip/Three-models-of-SDN-explained