s. This layer is designed modularly. It contains the following three key components: The base network service functions gather all the important information and statistics about the network. It includes topology manager that stores the topology, the statistics manager that collects statistical information from managed switches, the for- warding rule manager that handles rule installation and updates, the inventory manager that maintains database of discovered switches, and finally, the host tracker that tracks the location of end hosts in the entire network. The platform network service functions perform various network- ing tasks that serve as service to others. For example, the Affinity metadata service allows application to define certain workloads. The virtual tenant network manager creates and manages multi-tenant virtual network. The L2 switch function provides Layer 2 switching LEGEND AAA: Authentication Authorization & Accounting OVSDB: Open vSwitch DataBase Protocol AuthN: Authentication PCEP: Path Computation Element Communication Protocol BGP: Border Gateway Protocol PCMM: Packet Cable MultiMedia DAYLIGHT COPS Common Open Policy Service Plugin2OC: Plugin To OpenContrail DLUX: OpenDaylight User Experience SDNI SDN Interface (Cross-Controller Federation) DDoS: Distributed Denial Of Service SFC: Service Function Chaining DOCSIS Data Over Cable Service Interface Specification SNBI: Secure Network Bootstrapping Infrastructure FRM: Forwarding Rules Manager SNMP: Simple Network Management Protocol HELIUM GBP:Group Based Policy TTP: Table Type Patterns LISP: Locator/Identifier Separation Protocol VTN: Virtual Tenant Network OpenStack Network Applications Coordinator Neutron Wrapper Protection Orchestrations & Services AAA - AuthN Filter OpenDaylight APIs (REST) Base Network Service Functions DOCSIS OpenStack Service Service Abstraction Topology Stats Switch Manager Manager Manager Tracker OVSDB Controller Manager Neutron Plugin20C Service Switch Service Aggregator Platform Service Abstraction Layer (SAL) (Plug