Software Defined-Networking

Network Policies Access control: reachability – Alice can not send packets to Bob Application classification – Place video traffic in the gold queue

Network Management: Past

Network Management: Future Controller

Networking Yesterday Data plane – Determines how to forward a packet – Looks up the forwarding table to determine output port for a packet Control plane – Determines how to populate the forwarding tables – Translate user commands into hardware ACLs, MPLS – Runs a bunch of routing protocols IGPs: OSPF, IS-IS, RIP, & EGPs: BGP OSPF MPLS IP BGP VLAN Prefix Port MPLS Label Path

Networking Yesterday Control + Data-plane on each device – Network is a Distributed systems – Built to avoid failure (ArpaNet) A network is supported by an infinite number of protocols – New protocols developed to support new functionality – Takes time to standardize and to change the hardware Think: writing a distributed program in Perl – Error prone (Over 50% of errors caused by misconfig) – Time consuming IT Operators are the most costly portion of IT Takes up to 6 months for ISPs to roll out services for new costumers Very difficult to add new functionality into the network

Networking Evolution SDN is nothing new Circuit switching in Telephone networks RCP – Centralize control plane – Configure protocols rather than control plane 4D – clean-slate architecture Ethane/Sane – Centralize control plane – Forces switches do encrypt/decrypt each packet – No standardized interface

Requirements for SDN Operate without Guarantees – Need abstraction for distributed state – Want to deal with information without worrying about the fact that the state is from a distribution – Logically Centralized Compute configuration of each device – Need abstraction that simplifies configuration – Want to specify your intent  desired goal; the what – NOT: how to do it. Operate within given network-level protocol – Need abstraction for forwarding model – Hide details about hardware specifics – No need to worry about he exact harware OpenFlow Protocol Network Operating System Network Operating System Network Operating System Network Operating System

Enter Software Defined Networking: Separation of concerns – Network operator Specify behavior on a model Behavior == network policies – Network runtime Provides abstract view of the network Maps abstract view to global view Function of the types of network policies to be supported – Network Operation System Maps global view to physical view Translate abstract commands to device configuration Device interface: forwarding abstractions

Thinks to think about Distributed state abstraction – What is the right central view Configuration abstraction – What should the interface to the Switch hardware look like Forwarding abstraction – What to expose to the network operator

SDN Network Network Controller Network Operation System

OpenFlow Protocol Message between controller and switches – Synchronous Stats, Flow-mods – Asynchronous Packet-in Abstract hardware details Allows direct control over forwarding table : Fwd Port 1 A2:e3:f1:ba:ea:23:* Drop Match Action

The SDN Stack Controller 13 NetFPGA Software Ref. Switch Software Ref. Switch Broadcom Ref. Switch Broadcom Ref. Switch OpenWRT PCEngine WiFi AP Commercial Switches OpenFlow Switches Open vSwitch HP, NEC, Pronto, Juniper.. and many more

The SDN Stack Controller NOX 14 NetFPGA Software Ref. Switch Software Ref. Switch Broadcom Ref. Switch Broadcom Ref. Switch OpenWRT PCEngine WiFi AP Commercial Switches OpenFlow Switches … … Open vSwitch HP, NEC, Pronto, Juniper.. and many more Beacon Trema Maestro

Controllers 15 NameLangOriginal AuthorNotes OpenFlow Reference CStanford/Niciranot designed for extensibility NOXPython, C++Niciraactively developed BeaconJavaDavid Erickson (Stanford)runtime modular, web UI framework, regression test framework MaestroJavaZheng Cai (Rice) TremaRuby, CNECincludes emulator, regression test framework RouteFlow?CPqD (Brazil) virtual IP routing as a service POXPython FloodlightJavaBigSwitch, based on Beacon Too many to easily keep track of…

The SDN Stack Controller NOX Slicing Software FlowVisor Console 16 NetFPGA Software Ref. Switch Software Ref. Switch Broadcom Ref. Switch Broadcom Ref. Switch OpenWRT PCEngine WiFi AP Commercial Switches OpenFlow Switches … … Open vSwitch HP, NEC, Pronto, Juniper.. and many more Beacon Trema Maestro

FlowVisor Creates Virtual Networks OpenFlow Switch OpenFlow Switch OpenFlow Switch OpenFlow Protocol FlowVisor Simple switch CloudNaaS OpenFlow Protocol Stratos Reservations FlowVisor slices OpenFlow networks, creating multiple isolated and programmable logical networks on the same physical topology. Each application runs in an isolated slice of the network. 17

The SDN Stack Controller NOX Slicing Software FlowVisor Console 18 Applications CloudNaaS Simple Switch … … Stratos NetFPGA Software Ref. Switch Software Ref. Switch Broadcom Ref. Switch Broadcom Ref. Switch OpenWRT PCEngine WiFi AP Commercial Switches OpenFlow Switches … … Open vSwitch HP, NEC, Pronto, Juniper.. and many more Beacon Trema Maestro

The Dark Side of SDN “Logically” centralized controller – Scalability – Fault tolerance Flowtable entries – Limited number of TCAM entries – Can only support so many TCAM entries SDN Abstractions – Currently one set of abstraction for all devices – Edge and Core fundamentally different – Switches Versus Middleboxes