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 †Cornell □Software Driven Networks Problem Statement, T. Nandeau, Sept □Formal Specification Framework for Software-Defined Networks (SDN), Shin et al. □Three models of SDN explained, Tom Noelle explained explained