Distributed Clouds and Software Defined Networking

Rick McGeerChief Scientist, US IGNITE

October 7, 2013

Federated Local Clouds and Software Defined Networking

Complementary Technologies for the Next-Generation Internet

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Or, A Post-Hoc Justification for the Last 10 Years of My

Life

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The Future is Distributed Clouds integrated with

Software-Defined-Networks!

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SDN is a set of abstractions over the

networking control plane

Proxies are an essential element of

the Internet Architecture

Shouldn’t there be an abstraction architecture for proxies?

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Links

http://www.youtube.com/watch?v=eXsCQdshMr4

http://pages.cs.wisc.edu/~akella/CS838/F09/838-Papers/APST05.pdf

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.20.123&rep=rep1&type=pdf

Network Challenges

• Original Concept of the Network: dumb pipe between smart endpoints– Content-agnostic routing– Rates controlled by endpoints– Content- and user-agnostic forwarding

• Clean separation of concerns– Routing and forwarding by network elements– Rate control, admission control, security at endpoints

Clean separation of concerns doesn’t work very well

• Need application-aware stateful forwarding (e.g., multicast)

• Need QoS guarantees and network-aware endpoints– For high-QoS applications– For lousy links

• Need in-network security and admission control– Endpoint security easily overwhelmed…

Some Examples

• Load-balanced end-system multicast• Adaptive/DPI-based Intrusion Detection• In-network transcoding to multiple devices• Web and file content distribution networks• Link-sensitive store-and-forward connection-splitting TCP proxies• Email proxies (e.g., MailShadow)• In-network compression engines (Riverbed)• Adaptive firewall• In-situ computation for data reduction from high-bandwidth

sensors (e.g., high-resolution cameras)

Common Feature

• All of these examples require some combination of in-network and endpoint services– Information from the network– Diversion to a proxy– Line-rate packet filtering

• All require endpoint processing– Stateful processing– Connection-splitting– Filesystem access

Historic Solution: Middleboxes

• Dedicated network appliances to perform specific function

• Gets the job done, but…– Appliances proliferate (one or more per task)– Opaque– Interact unpredictably…

• Don’t do everything– E.g., generalized in-situ processing engine for data reduction

• APST, 2005: “The ability to support…multiple coexisting overlays [of proxies]…becomes the crucial universal piece of the architecture.”

OpenFlow and SDN

• L2/L3 Technology to permit software-defined control of network forwarding and routing

• What it’s not:– On-the-fly software decisions about routing and forwarding– In-network connection-splitting store-and-forward– In-network on-the-fly admission control– In-network content distribution– Magic….

• What it is:– Table-driven routing and forwarding decisions (including drop and multicast)– Callback protocol from a switch to a controller when entry not in table (“what do I

do now?”)– Protocol which permits the controller to update the switch

Openflow rationalizesrouting.

It does nothing aboutmiddlebox services

In-Network Processing

• L4/L7 Services provided by nodes in the network– TCP/Application layer proxies– Stateful/DPI based intrusion detection– Application-layer admission control– Application-layer load-balancing– ….

• Key features– Stateful processing – Transport/Application layer information required

Middleboxes and the Network

• Classic View: Proxies and Middleboxes are a necessary evil that breaks the “end-to-end principle” (Network should be a dumb pipe between endpoints)

• Modern View (Peterson): “Proxies play a fundamental role in the Internet architecture: They bridge discontinuities between different regions of the Internet. To be effective, however, proxies need to coordinate and communicate with each other.”

OpenFlow lets usprogram routing protocols

Question: how can weprogram a network of

middleboxes?

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Shenker’s SDN Architecture

Specification of a virtual network, with explicit forwarding instructions

Translation onto OpenFlow rules on physical network

Effectuation on physical network

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Perfect for L1-L3

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Key Function we want: Add Processing Anywhere in the Virtual Network

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Going from Virtual Network to Virtual Distributed System

Specification of a virtual distributed, with explicit forwarding instructions BETWEEN specified VMs

Translation onto OpenFlow rules on physical network AND instantiation on physical machines at appropiate sites

Effectuation on physical network AND physical clouds

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Key Points

• Federated Clouds can be somewhat heterogeneous– Must support common API– Can have some variants (switch variants still present a

common interface through OpenFlow)

• DSOS is simply a mixture of three known components:– Network Operating System– Cloud Managers (e.g., ProtoGENI, Eucalytpus, OpenStack)– Tools to interface with Network OS and Cloud Managers

(nascent tools under development)

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Implications for OpenFlow/SDN

• Southbound API (i.e., OpenFlow): minimal and anticipated in 1.5– “Support for L4/L7 services”, aka, seamless redirection

• Northbound API– Joint allocation of virtual machines and networks– Location-aware allocation of virtual machines– WAN-aware allocation of networks– QoS controls between sites

• Build on/extend successful architectures– “Quantum for the WAN”

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Two Initial Attempts

• IGNITE Technical Architecture• GENI Mesoscale

Existing ISP connects

Layer 2 Ignite Connect(1 GE or 10GE)

Layer 3 GENI control plane

Layer 2 connect to subscribers

Existing head-end

New GENI / Ignite rack pair

OpenFlow switch(es)FlowvisorRemote managementInstrumentationAggregate managerMeasurementProgrammable serversStorageVideo switch (opt)

Home

Most equipment not shown

U.S. Ignite City Technical Architecture

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GENI Mesoscale

• Nationwide network of small local clouds• Each cloud

– 80-150 worker cores– Several TB of disk– OpenFlow-native local switching

• Interconnected over OpenFlow-based • Local “Aggregate Manager” (aka controller)• Two main designs with common API

– InstaGENI (ProtoGENI-based)– ExoGENI (ORCA/OpenStack-based)

• Global Allocation through federate aggregate managers• User allocation of networks and slices through tools (GENI portal, Flack)

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Thanks!