Network Virtualization Based on Flows

Transcription

1 TERENA NETWORKING CONFERENCE 2009 June 9, 2009 Network Virtualization Based on Flows Peter Sjödin Markus Hidell, Georgia Kontesidou, Kyriakos Zarifis KTH Royal Institute of Technology, Stockholm

2 Outline OpenFlow background Motivation Technical background OpenFlow features Current activities Virtualization based on OpenFlow Model Project status 2

3 OpenFlow Background Originally proposed by a group of researchers from Stanford University, University of Washington, MIT, Princeton University, University of California Berkeley, and Washington University in St. Louis Opens up commercial networking hardware to researchers Gives access to a flow table, for controlling packet forwarding in switches and routers Allows researchers to experiment with new functionality in networks Routing protocols Packet processing Alternatives to IP... 3

4 OpenFlow Switching OpenFlow Switch Controller PC sw Secure Channel SSL hw Flow Table Source: N. McKeown, Stanford University 4

5 Flow Table Entry Rule Action Stats Packet + byte counters 1. Forward packet to port(s) 2. Encapsulate and forward to controller 3. Drop packet 4. Send to normal processing pipeline Switch Port + mask MAC src MAC dst Eth type VLAN ID IP Src IP Dst IP Prot TCP sport TCP dport Source: N. McKeown, Stanford University 5

6 OpenFlow-Enabled Commercial Switch Three components added: OpenFlow protocol Secure channel Flow table Controller How? Secure channel in OS S/W OpenFlow in OS S/W Flow table in switch H/W TCAMs OpenFlow-enabled Commercial Switch Normal Software Secure Channel OpenFlow Straight-forward to implement? Normal Datapath Flow Table Source: N. McKeown, Stanford University 6

7 OpenFlow Protocol Three message types: Controller-to-switch messages Configuring the switch Managing the flow table Figuring out switch capabilities Asynchronous messages From switch to controller Report events (switch state, network state, etc) Symmetric messages Sent in either direction Controller Diagnose problems in switch-controller connection OpenFlow Protocol OpenFlow Switch 7

8 Per-Flow Slicing Flowspace Flow-based substrate General and flexible Backwards compatibility Tunnels, VLANs, etc, can be represented as flows No packet modifications No need for encapsulation or decapsulation No end-point modifications 8

9 Centralized Model of Control OpenFlow Controller OpenFlow protocol Separation of control and data Flexibility in routing decisions, management policies, etc OpenFlow Network 9

10 OpenFlow and FEDERICA FEDERICA uses different techniques for dividing network resources into slices OpenFlow is a technique for setting up flow tables in switches Consider OpenFlow as a slicing method for FEDERICA General and flexible Slicing on a per-flow basis Flow-based substrate 10

11 FEDERICA OpenFlow Research Explore OpenFlow as an architecture for network virtualization Design a virtualization layer on top of OpenFlow Provide virtualization service interface 11

12 Key Issues Definition of virtual network abstraction Knowledge about the network Virtual network specification Provisioning of virtual networks Selection of nodes and links Mapping to OpenFlow operations Access control, authorization and validation Legitimate users Resolving conflicts between virtual networks 12

13 OpenFlow Virtualization Virtualization Controller OpenFlow protocol Separation of control and data Flexibility in routing decisions, management policies, etc OpenFlow Network 13

14 OpenFlow Virtualization Virtualization Controller OpenFLow protocol Virtualized OpenFlow Network 14

15 Activities Design and implementation Key components Small-scale experimental study Linux environment Large-scale experimental evaluation FEDERICA OpenFlow-enabled equipment 15

16 Conclusions OpenFlow Protocol for controlling flow tables in switches General mechanism for flow-based switching Management paradigm based on centralized control Decoupled from switching Virtualization mechanism for FEDERICA Flow-based slicing Work in progress on design and evaluation 16