Serial Composition of

Heterogeneous Control Planes

Kirill Kogan

Purdue University

with Advait Dixit and Patrick Eugster

SDN view

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SDN Controller Platform Logically

centralized

network

control Southbound API

How should we introduce new services?

S1 S2 SN … S3

Northbound API

Flexibility of Controllers

• Majority of controllers are monolithic.

• [Beacon] allows dynamic addition of services (but all services are written in Java and require beacon’s API).

• [Yanc] exposes network configuration using the file system (services can be written in any language but requires Yanc’s file system layout).

• [HotSwap] supports upgrade from one version to the other.

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SDN view

4

SDN Controller Platform

S1 S2 SN … S3

Standardization of

Northbound API ?

Parallel Composition of Controllers

(resolved)

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SDN Controller 1

S11 S12 S1N …

SDN Controller 2

S21 S22 S2M …

[FlowVisor]

Problem statement Problem: Given a set of desired services implemented

on different types of OpenFlow controllers, apply a serial composition of the desired services on the same traffic.

Requirements:

1. Only the South-bound API is standardized.

2. No code changes in implementing controllers.

3. A composition is built in config time.

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Serial Composition of Controllers

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SDN Controller C1

S11 S12 S1K …

SDN Controller CN

SN1 SN2 SNM …

FlowBricks

…

fence

Example of Serial Composition

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C1

QoS

FlowBricks

C2

NAT

C3

Routing

OpenFlow Limitations

• No explicit packet drop action.

• Non feasible to implement fence (solution: introduction of Ececute-Actions Instruction).

• Packet processing cannot go from a higher flow table number to a lower one (that limits a number of potential policies in FlowBricks).

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Our Contribution • Implemented FlowBricks on top of FloodLight.

• We conducted experiments to show that FlowBricks does not impact significantly response time and scalability.

• We plan to address space time tradeoff similarly to [SST].

Implementation:

http://web.ics.purdue.edu/~dixit0/flowbricks.tgz

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References [Beacon] The Beacon OpenFlow Controller’

[Yanc] Applying Operating Systems Principles to SDN

Controller Design’

[HotSwap] HotSwap: Correct and Efficient Controller

Upgrades for Software-Defined Networks

[FlowVisor] Can the Production Network be the Testbed

[Pyretic] Composing Software-Defined Networks

[SST] Space and Speed Tradeoffs in TCAM Hierarchical

Packet Classification

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Backup Slides

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Concatenation of Flow Tables

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