Software Defined Networking Data centre perspective: Open Flow

Transcription

1 Software Defined Networking Data centre perspective: Open Flow Seminar: Prof. Timothy Roscoe & Dr. Desislava Dimitrova D. Dimitrova, T. Roscoe

2 OpenFlow Specification, protocol, architecture SDN Controller Specification Control channel Protocol Switch Specification D. Dimitrova, T. Roscoe

3 OpenFlow Why standard? ForCES vs OpenFlow Both: Separation control & data plane ForCES: distributed control now distributed OF controllers OF: changes network architecture now switch-controller task distribution ForCES from 2001 to 2014 D. Dimitrova, T. Roscoe

4 OpenFlow: Protocol SDN Controller Control channel OF agent Flow table 1 Meter table Flow table 2 Switch Group table Action D. Dimitrova, T. Roscoe

5 OpenFlow: Protocol How to talk & what to say Flow message Packet_In Packet_Out Flow_Mod Flow_Expired Semantic Missing flow entry, request controller Instructions to handle packet Instructions for flow entry Flow expired D. Dimitrova, T. Roscoe

6 OpenFlow: Protocol How to talk & what to say From to Duration stats How long can we go on? Started from 12 fields Add on MPLS (1.1.0), IPv6 (1.2.0) D. Dimitrova, T. Roscoe

7 OpenFlow: Specification How to act and what to do Table Action Does that scale? Table X SRAM Table Y TCAM Table Z TCAM Action Group table Ingress Egress Table A Table B Table C Table Y Table Z Action Group table D. Dimitrova, T. Roscoe

8 OpenFlow: Specification How to act and what to do idle_timeout hard_timeout Move between ASIC and CPU D. Dimitrova, T. Roscoe

9 OpenFlow: Specification Table management Eviction and capacity events for flow table control Controller-to-switch Multiple controllers per switch Multiple connections per controller switch pair Flow monitoring per controller SDN Controller SDN Controller Switch D. Dimitrova, T. Roscoe

10 OpenFlow: Next steps Source Jordan McCoy, D. Dimitrova, T. Roscoe

11 Capabilities D. Dimitrova, T. Roscoe

12 Capabilities: Centralized control Semantics Centralized control OpenFlow SDN Controller Control channel OpenFlow Flow Abstractions Distributed forwarding Switch Switch Flow abstractions: How to process What to process D. Dimitrova, T. Roscoe

13 Capabilities: Configuration ease Standard interface Network programming languages Virtualization!= SDN Organization B Organization A Flow Table B Flow Table A Switch Controller B Controller A D. Dimitrova, T. Roscoe

14 Capabilities: Dynamic updates Real time adaptation Real time? Applications Failure recovery Load balancing Access control Verification!= OF application Traffic stats Real-time adaptation Controller: recompute Verification Switch: update Topology events D. Dimitrova, T. Roscoe

15 Capabilities: Traffic analytics Per-flow statistics Applications Re-routing Security threats detection SLA guarantees Traffic shaping D. Dimitrova, T. Roscoe

16 Challenges D. Dimitrova, T. Roscoe

17 Challenges: Scalability Bandwidth Delay Lookup speed Buffer size Bandwidth SDN Controller Local CPU/NPU Switching fabric Processing delay # flows Bandwidth Updates rate Switch CPU Flow table size Rule processing time D. Dimitrova, T. Roscoe

18 Challenges: Resilience Compatibility: Controllers & OF spec SDN Controller SDN Controller Flow rule validation Behaviour verification Quick recovery from link failures Local CPU/NPU Switching fabric Flow rule verification D. Dimitrova, T. Roscoe

19 Challenges: Security SDN Controller SDN Controller Intruder detection Secure channel Local CPU/NPU Switching fabric Flow table modification D. Dimitrova, T. Roscoe

20 Contact information and credits ETH Zurich Systems Group Universitättrasse Zürich ETH Zurich, February 2016 D. Dimitrova, T. Roscoe