NFV Management & Orchestration (MANO) Framework

According to European Telecommunications Standards Institute Industry Specification Group (ETSI ISG NFV), the MANO function is responsible for deploying and connecting hosted elements or virtual network functions.

NFV MANO is broken up into three functional blocks:

  • Virtualized Infrastructure Manager (VIM)
  • VNF Manager (VNFM)
  • NFV Orchestrator (VNFO) and a group of repositories

NFVI block is the NFV Infrastructure that includes physical (server, storage etc.), virtual resources (VM’s) and Hypervisor in an NFV environment

There are two blocks outside of MANO, i.e. Element Management System (EMS) and OSS/BSS. They are not directly part of the MANO but they do exchange information with it.

Here is a short description of each of these blocks.

Virtualized Infrastructure Manager (VIM)

The typical tasks, VIM delivers:

  • Manages life cycle of virtual resources in an NFVI domain – creates, maintains and tears down virtual machines (VMs) from physical resources in an NFVI domain
  • Keeps inventory of virtual machines (VMs) associated with physical resources
  • Performance and fault management of hardware, software and virtual resources
  • Keeps north bound APIs and thus exposes physical and virtual resources to other management systems.

There may be multiple VIMs in an NFV architecture, each managing its respective NFV Infrastructure (NFVI) domain.

Virtual Network Function Manager (VNFM)

VNF Manager oversees lifecycle management of VNF instances. For review, VNF is a virtualized network element like vDPI, vRouter, vSwitch etc.

Specifically, VNFM does the following:

  • VNFM manages life cycle of VNFs – it creates, maintains and terminates VNF instances
  • It is responsible for the FCAP (Fault, Configuration, Accounting, Performance and Security Management) of VNFs
  • It scales up/ down VNFs which results in scaling up and scaling down of CPU usage.
  • Plays a coordination and adaptation role for configuration and event reporting between NFVI and EMS

There may be multiple VNFMs managing separate VNFs or there may be one VNFM managing multiple VNFs

NFV Orchestrator (NFVO)

NFVO coordinates the resources from different VIMs by engaging with the VIMs directly through their north bound APIs instead of engaging with the NFVI resources, directly.

Although, NFVO manages/coordinates the creation of an end to end service that involves VNFs from different VNFMs domains. This process can be described in the following way:

  • Service Orchestration creates end-to-end service between different VNFs. It achieves this by coordinating with the respective VNFMs so it does not need to talk to VNFs directly
  • Service Orchestration can instantiate VNFMs, where applicable
  • It does the topology management of the network services instances.


  • VNF Catalog is a repository for all VNF Descriptors (VNFD). VNFD is a deployment template which describes a VNF in terms of its deployment and operational behavior requirements. It is primarily used by  VNFM in the process of VNF instantiation and lifecycle management of a VNF instance
  • NS Catalog is the catalog of the usable Network Services
  • NFV Instances holds all details about Network Services instances and related VNF Instances.
  • NFVI Resources is a repository of NFVI resources utilized for the purpose of establishing NFV services

Reference Points

MANO has multiple reference points that are shown as interconnection points between the functional blocks as shown i.e. Or-Vi, NF-Vi, Or-Vnfm etc. The Reference Point is an architectural concept that defines and exposes an external view of a functional block.


At the Internet Engineering Task Force (IETF) meeting in March 2014, NFV MANO announced a series of adopted interfaces for the MANO architecture, as well as said improvements were continual. An important next step for NFV MANO is to include SDN Controller into the architecture.

B4N NFV Services are designed to be fully compliant with MANO framework.

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