White Paper Contrail Architecture 1 Contrail Architecture White Paper Table of Contents Executive Summary ........................................................................................................................................................................................................4 Introduction ........................................................................................................................................................................................................................4 Overview of Contrail .......................................................................................................................................................................................................4 Use Cases ....................................................................................................................................................................................................................4 Contrail SDN Controller and the vRouter ........................................................................................................................................................ 5 Virtual Networks........................................................................................................................................................................................................ 5 Overlay Networking .................................................................................................................................................................................................. 5 Overlays Based on MPLS L3VPNs and EVPNs ............................................................................................................................................. 5 Contrail and Open Source .....................................................................................................................................................................................6 Scale-Out Architecture and High Availability .......................................................................................................................................................6 The Central Role of Data Models: SDN as a Compiler................................................................................................................................7 Northbound Application Programming Interfaces .......................................................................................................................................7 Graphical User Interface ........................................................................................................................................................................................8 An Extensible Platform ...........................................................................................................................................................................................8 Contrail Architecture Details .......................................................................................................................................................................................8 Nodes .......................................................................................................................................................................................................................... 10 Compute Node ...................................................................................................................................................................................................11 vRouter Agent ...........................................................................................................................................................................................................12 vRouter Forwarding Plane ....................................................................................................................................................................................12 Control Node ......................................................................................................................................................................................................13 Configuration Node ..........................................................................................................................................................................................14 Analytics Node ..................................................................................................................................................................................................15 The Contrail Forwarding Plane .................................................................................................................................................................. 16 MPLS over GRE ......................................................................................................................................................................................................... 17 VXLAN .......................................................................................................................................................................................................................... 17 MPLS over UDP ....................................................................................................................................................................................................... 18 Overlay Multicast Trees ....................................................................................................................................................................................... 20 Underlay Multicast Trees .....................................................................................................................................................................................22 Comparison ...............................................................................................................................................................................................................22 Service Chaining ......................................................................................................................................................................................................23 Control and Management Plane Protocols ..................................................................................................................................................24 IF-MAP .................................................................................................................................................................................................................24 XMPP ....................................................................................................................................................................................................................24 BGP .......................................................................................................................................................................................................................25 Sandesh ..............................................................................................................................................................................................................25 OpenStack Integration .........................................................................................................................................................................................25 Security .......................................................................................................................................................................................................................25 Horizontal Scalability and High Availability .................................................................................................................................................26 Control Nodes ...................................................................................................................................................................................................26 Configuration Nodes ......................................................................................................................................................................................26 Analytics Nodes ...............................................................................................................................................................................................26 vRouter Agent ...................................................................................................................................................................................................26 vRouter Forwarding Plane ............................................................................................................................................................................26 The Data Model .............................................................................................................................................................................................................. 27 Programming Model .............................................................................................................................................................................................. 27 Configuration