CONVERGENCEKO Meeting

EXPRESS: Implementing an SDN infrastructure over a federation of testbeds

(experiment within the OpenLab project)

Stefano Salsanoand the EXPRESS team: Giuseppe Siracusano, Federico Griscioli,

Pier Luigi Ventre, Claudio Pisa, Andrea Detti, Nicola Blefari-Melazzi…

CNIT / University of Rome «Tor Vergata»

Pre-FIA workshop on Testbed Interoperability - Athens, March 17th 2014

EXPRESS objectives

• Design an innovative, resilient SDN system to extend the SDN applicability domain from fixed networks to intermittently connected network, like wireless mesh networks.

• Evaluate our solutions over a federation of three OpenLab testbeds (PlanetLab, NITOS and W-iLab.t), where PlanetLab plays the role of the core fixed network and NITOS and W-iLab.t play the role of the wireless mesh networks

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Outline

• wmSDN : wireless mesh Software Defined Network– SDN in a highly dynamic networking environment with network

partitions /merging– Wireless Mesh Router (WMR) architecture– Controller selection aspects

• Testebed interoperability aspects

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Internet

wmSDNwireless mesh Software Defined Network

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GW to Internet

Wireless Mesh Router(WMR)Client

Hosts

Controller

Controller

Internet

wmSDNcontrol plane connections with controllers

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GW to Internet

Wireless Mesh Router(WMR)Client

Hosts

Controller

Controller

Internet

wmSDNcontrol plane connections with controllers

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GW to Internet

Wireless Mesh Router(WMR)Client

Hosts

Controller

Controller

Internet

wmSDN“in-band” control plane

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GW to Internet

Wireless Mesh Router(WMR)Client

Hosts

Controller

Controller

wmSDNnetwork partitions

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GW to Internet

Wireless Mesh Router(WMR)Client

Hosts

Controller

Controller

Internet

wmSDNnetwork partitions

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Wireless Mesh Router(WMR)Client

Hosts

Controller

Controller

Internet

GW to Internet

Control and data plane

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• The OLSR routing protocol for Mobile Adhoc Networks is used to establish a basic IP connectivity in the Wireless Mesh Net

• The OpenFlow/SDN control plane (switch-to-controller communication) goes “in-band” over the basic IP connectivity

• Data plane uses the IP connectivity or an “SDN based connectivity” in a flexible way

• When using SDN based connectivity, the routing of packet flows is decided by the SDN controller

Control and data plane

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IP baseddata-plane

OpenFlow baseddata-plane

IP basedcontrol-plane

Secondary Mesh controller

Primary Mesh controller

OF Switch

EFCM

WMR - Wireless Mesh Router

HomeController

OLSRdaemon

Initial configurationof flow tables

Sends and receiveOLSR packets

Can configure the flow table for data plane

IP forwarding

Handles basicIP forwarding

Check connectivity with controllers and liveliness of

controllers

wmSDN: architecture• OpenFlow controllers

• OLSR Daemon

• OpenFlow switch(Open vSwitch)

• EFCM - External Flow table and Controller Manager

OpenFlowSwitch Flow Table

EFCM

OLSRdaemon

Wireless Mesh Router

ethYwlanZ…

Non SDN interfaces

OpenFlowController(s)

Config. flow table for data traffic

handled by SDN

wlan0

10.0.0.x1vi0

tap9

IP forwarding

10.0.0.x9vi9

interface to wireless Testbes

Tunnell to wired Testbed

SDN interfaces

Details of WMR node architecture

• Each physical interface is associated with a virtual interface

• Traffic can forwarded in two ways– IP forwarding which operates on the

virtual interfaces (routing is set by OLSR)– with SDN rules in the OF switch

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Master controller election in SDN fixed nets

• Communications among controllers are relatively reliable -> the controllers can run a master election procedure to take control of each switch

• (Implementation issue) Open vSwitch can only connect to a preconfigured set of controllers

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Master controller election in SDN fixed nets

• In a traditional OF environment communications among controllers are relatively reliable -> the controllers can run a master election procedure to take control of each switch

• (Implementation issue) Open vSwitch can connect to a preconfigured set of controllers (must be known to the switch in advance)

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Controller election

Master controller election in SDN fixed nets

• In a traditional OF environment communications among controllers are relatively reliable -> the controllers can run a master election procedure to take control of each switch

• (Implementation issue) Open vSwitch can connect to a preconfigured set of controllers (must be known to the switch in advance)

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From Master Election to Controller Selection

• WMRs select the more appropriate controller given the connectivity status of the network (Controller Selection)

• The Controller Selection procedure is performed by the EFCM

• Simple strategy, based on a “Hierarchy of Controllers”: select the connected controller with the highest level in the hierarchy

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From Master Election to Controller Selection

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Internet

GW to Internet

Wireless Mesh Router(WMR)Client

Hosts

Controller

Controller

Experimenting in OpenLab testbeds

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• Wireless testbeds:– W.iLab-T – NITOS

• Fixed testbed– PlanetLab

• Interconnection of Wireless testbeds with fixed “backbone”

• Ethernet over UDP tunnels

across Planet Lab Europe to interconnect the testbeds

Wireless Mesh 1formed by SDN APs

Wired Core Networkformed by SDN nodes Origin

Controller(home)

Wireless Mesh 2formed by SDN APs

Surrogatecontroller

(mesh, built-in)

Surrogatecontroller

(mesh, built-in)

NITOS

W.ilab-t

Planet Lab

Testbeds interconnection issues

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W.ilab-t

Planet Lab

Planet Lab nodes actingas L2 switches

External hostwith public IP address

External hostwith public IP address

Management host

Ethernet in UDP tunnels

Creates the L2 overlayPrivate IPaddress

Private IPaddress

Solutions for testbeds interconnection

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W.ilab-t

Planet Lab

Planet Lab nodes actingas L2 switches

External hostwith public IP address

Management host

Ethernet in UDP tunnels

Creates the L2 overlayPrivate IPaddress

Private IPaddress

NAT

External hostwith public IP address

NITOS

Solutions for testbeds interconnection

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W.ilab-t

Planet Lab

Planet Lab nodes actingas L2 switches

External hostwith public IP address

External hostwith public IP address

Management host

Ethernet in UDP tunnels

Creates the L2 overlayPrivate IPaddress

Private IPaddress

PFPort Forwarder

Configures the PF

NITOS

Testbeds interconnection issues

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W.ilab-t

Planet Lab

Planet Lab nodes actingas L2 switches

Management host

Ethernet in UDP tunnels

Creates the L2 overlay, taking care of the

connections coming from NAT boxes

Private IPaddress

Private IPaddress

NAT

NAT

PLE node

OVS switch

pl0

NAT (2)

pl1tap0

Private IPaddresses

Internet

W-iLab.t

Port Forwarder (1)

or NAT (2)

tap0

Private IPaddresses

NITOS

Solutions for testbed interconnection

• (1) “Port Forwarder” running in the node that interconnects a testbed with the Internet, it can run at kernel level or application level

• (2) Regular NAT translation of an outgoing UDP flow from a node in the testbed and terminating in the tunnel endpiont node in Planet Lab

Controller selection over federated testbeds

• The Network is divided in 3 partitions: blue, green and gray • WMRs in different partition are connected to the best available

controller (or using only IP routing if no controller is available)

Gateway to internet

Access net Access

net

192.168.1.0/24 192.168.2.0/24

WMR

WMR WMR

Wirelessinterfaces

Wilab Mesh Controller

WMR

Nitos Mesh Controller

WMR

10.0.0.210.0.0.3

10.0.0.8

10.0.0.4

10.100.100.100

10.100.100.101

10.0.0.7

Tunnel to PLE node

HomeController

Fixedbackbone

Wirelessinterfaces

Tunnel to PLE node

10.100.100.102

10.0.0.910.0.0.9

NITOS

PLANET LAB

WILAB

Controller selection over federated testbeds

• Network partition are joined together• WMRs are connected to the “best” available controller

Gateway to internet

Access net Access

net

192.168.1.0/24 192.168.2.0/24

WMR

WMR WMR

Wirelessinterfaces

Wilab Mesh Controller

WMR

Nitos Mesh Controller

WMR

10.0.0.210.0.0.3

10.0.0.8

10.0.0.4

10.100.100.100

10.100.100.101

10.0.0.7

Tunnel to PLE node

HomeController

Fixedbackbone

Wirelessinterfaces

Tunnel to PLE node

10.100.100.102

10.0.0.910.0.0.9

NITOS

PLANET LAB

WILAB

Thank you for your attentionQuestions?

Stefano Salsano, Ph. D.Assistant professor

e-mail: stefano.salsano@uniroma2.ithttp://netgroup.uniroma2.it/Stefano_Salsano

Phone: +39 06 7259 7770Fax: +39 06 7259 7435

UNIVERSITY OF ROME “TOR VERGATA”Department of Electronics Engineering

Via del Politecnico, 1 - 00133 Rome - Italy

http://netgroup.uniroma2.it/wmSDN/