Management and orchestration (MANO) is an essential part of the ETSI network functions virtualization (NFV) architecture. But taking the MANO concept from a diagram to implementation is not easy. Here is what is needed to change that situation:
What is MANO?
MANO challenge #1: onboarding VNFs
One of the key takeaways from the above definition is the lifecycle management of virtualized network functions (VNFs). As a result, an essential characteristic of orchestrators is the ease with which they can onboard new VNFs. Onboarding consists of:
- Catalog. The first step is adding the VNF to the orchestrator’s catalog, including the VNF descriptor (VNFD). The VNFD provides information about the requirements of the VNF in terms of virtual CPU cores, memory, storage, and its capabilities regarding networking and elasticity.
- Initialization. The next step is that the orchestrator must be given information about what is required to instantiate and network the VNF. This could be done through a standard protocol such as CloudInit, or it may require scripting through the virtual console of the VNF.
- Lifecycle Management. After instantiating a VNF, the orchestrator must be able to monitor its health and apply scaling operations when applicable and recovery operations when required.
Making MANO easy requires that the above procedures can be performed by a telco operator through configuration, without the involvement of the supplier of the orchestrator, and without requiring programmatic changes to the orchestrator.
MANO challenge #2: real-world operations
NFV is now moving from the RFx and lab stage to field deployments. Doing so means addressing a number of operational questions. Carrier-class orchestrators must have the following characteristics:
- Scalability. They must be able to support thousands of services, VNFs, and servers. This means being constructed using web-scale techniques of horizontal scalability.
- Security. The orchestrator must support multi-tenancy to separate operations on different services on behalf of different customers.
- Upgradability. VNFs will change over time, and an orchestrator must be able to gracefully migrate between versions of a given VNF.
MANO challenge #3: integration with other systems
Automation is an essential goal for modern management systems, and this is especially true for NFV orchestrators. The following characteristics are required to facilitate automation:
- APIs. Orchestrators need to talk northbound to OSS/BSS systems, and southbound to controllers. Modern APIs and protocols such as representational state transfer (REST) ease the integration of an orchestrator with these external systems.
- Documented. The APIs should be documented in standard formats such as XML Schema Definition (XSD) and YANG to ease the job of integration.
- Componentized. In addition to the orchestration function proper, the MANO architecture also includes a VNF manager (VNFM) function. In general, a generic VNFM can handle the great bulk of VNFs. However, an orchestrator should also include an interface to support an external VNFM when required.
Real world experience helps
Experience is how we avoid mistakes. Sadly, mistakes are a primary way we gain experience. One of the big benefits of having been at the MANO game longer than most is that we have learned the hard lessons of deployment and have applied those lessons to our orchestrator. As a result, we have made the path to NFV much easier for our customers and partners.