This article explores how intent modeling can serve as a programming language for launching services with agility.
In Tom Nolle’s blog article titled What NFV Needs is “Deep Orchestration”!, he identifies the need for a modernized Business Support System and Operations Support System (BSS/OSS) to improve operations efficiency and service agility by extending service-level automation uniformly downward into the network resources, including the virtual network functions and the NFV infrastructure.
Service orchestration is the automation of processes to fulfill orders for life cycle managed information and communications technology services. Traditionally, this process automation problem has been solved through business process modeling and work flow management, which includes a great deal of system integration to glue together heterogeneous software components that do not naturally work together. The focus of process modeling is on “how” to achieve the desired result, not on “what” that result is. The “what” is the intent; the content of the order captures the intent.
To achieve agility in launching services, we must be able to model services in a manner that allows a service provider to redefine the service to suit the current business need. This modeling must be done by product managers and business analysts, experts in the service provider’s business. Any involvement of software developers and system integrators will necessarily require programming at a level of abstraction that is far below the concepts that are natural to the service provider’s business. The software development life cycle is very costly and risky, because the abstractions are so mismatched with the business. When service modeling directly results in its realization in a completely automated executable runtime without involving other humans in any software development activities, this becomes Programming for Non-programmers.
The key is Going Meta. The “what” metadata is the intent modeling. The “how” metadata is the corresponding fulfillment and provisioning behavior (service-level automation). If the “what” and “how” can be designed as a language that can be expressed in modular packages, which are reusable by assembling higher level intent based on lower level components, this would provide an approach that would facilitate the service agility users are looking for. Bundling services together and utilizing lower level services as resources that support a higher level service are familiar techniques, which would be familiar to users who are designing services. When users express themselves using this language, they are in fact programming, but because the language is made up entirely of abstractions that are familiar and natural to the business, it does not feel burdensome. General purpose programming languages like Java feel burdensome, because the abstractions are for a low level computational machine, not a high level business-oriented machine for service-level automation of human intent.
Our challenge in developing a modernized BSS/OSS is to invent this language for intent modeling for services. An IETF draft titled YANG Data Models for Intent-based NEtwork MOdel attempts to define a flavor of intent modeling for network resources. An IETF draft titled Intent Common Information Model attempts to define a flavor of intent modeling that is very general, but it is far removed from any executable runtime that can implement it, because it is so imprecise (not machine executable). ETSI NFV MANO defines an approach that captures intent as descriptors for network services as network functions and their connections. However, these abstractions are not expressive enough to extend upward into the service layer, across the entire spectrum of network technologies (physical and virtualized), and into the “how” for automation, to enable the composition of resources into services and the utilization of services as resources to support higher level services that can be commercialized. More thought is needed to design a good language for this purpose and a virtual machine that is capable of executing the code that is produced from it.