A Cloud-Native Network Function (CNF) is a software-implementation of a function, or application, traditionally performed on a physical device, but which runs inside
Linux containers
OS-level virtualization is an operating system (OS) paradigm in which the kernel allows the existence of multiple isolated user space instances, called ''containers'' ( LXC, Solaris containers, Docker, Podman), ''zones'' (Solaris containers), '' ...
(typically orchestrated by
Kubernetes).
The features that differ CNFs from VNFs (Virtualized Network Functions), one of the components of
Network Function Virtualization Network functions virtualization (NFV) is a network architecture concept that leverages the IT virtualization technologies to virtualize entire classes of network node functions into building blocks that may connect, or chain together, to create and ...
, is the approach in their orchestration.
In ETSI NFV standards, the Cloud-Native Network Functions are a particular type of Virtualized Network Functions and are orchestrated as VNFs, i.e. using the ETSI NFV MANO architecture and technology-agnostic descriptors (e.g. TOSCA, YANG). In that case, the upper layers of the ETSI NFV MANO architecture (i.e. the NFVO and VNFM) cooperate with a Container Infrastructure Service Management (CISM) function that is typically implemented using cloud-native orchestration solutions (e.g. Kubernetes).
The characteristics of Cloud-Native Functions are:
* Containerized
microservices that communicate with each-other via standardized
RESTful APIs
* Small performance footprint, with the ability to scale
horizontally
* Independence of
guest operating system, since CNFs operate as containers
* Lifecycle manageable by
Kubernetes, using container images registries such as OCI
Docker, and OS container runtime.
Relation to Network Function Virtualization
These characteristics address many of the common issues found with the first generation of
VNFs, by incorporating many of the innovations deployed commonly in the internet infrastructure. These include auto-scaling,
supporting a
continuous delivery
Continuous delivery (CD) is a software engineering approach in which teams produce software in short cycles, ensuring that the software can be reliably released at any time and, following a pipeline through a "production-like environment", withou ...
/
DevOps deployment model, and efficiency gains by sharing common services across platforms. Through
service discovery
Service discovery is the process of automatically detecting devices and services on a computer network. This reduces the need for manual configuration by users and administrators. A service discovery protocol (SDP) is a network protocol that hel ...
and orchestration, a system based on CNFs will be more resilient to node failure.
A specification of criteria to classify and characterize Cloud Native VNF implementations can be found in ETSI GS NFV-EVE 011.
Cloud Native Computing Foundation
The
Linux Foundation
The Linux Foundation (LF) is a non-profit technology consortium founded in 2000 as a merger between Open Source Development Labs and the Free Standards Group to standardize Linux, support its growth, and promote its commercial adoption. Additi ...
backed
Cloud Native Computing Foundation
The Cloud Native Computing Foundation (CNCF) is a Linux Foundation project that was founded in 2015 to help advance container technology and align the tech industry around its evolution.
It was announced alongside Kubernetes 1.0, an open sourc ...
project is actively supporting companies in contributing to open-source projects like
Kubernetes or
Prometheus, upon which Cloud Native Network Functions can be based on. The CNCF project also created a CNF Testbed, in order to facilitate a common test-ground for various cloud-native network functions.
[{{Cite news, last=cncf, date=2019-02-25, title=CNCF Launches Cloud Native Network Functions (CNF) Testbed, url=https://www.cncf.io/announcement/2019/02/25/cncf-launches-cloud-native-network-functions-cnf-testbed/, access-date=2020-07-22, website=Cloud Native Computing Foundation, language=en-US]
References
11. Cloud Native Computing Foundation, (http//www.cncf.io)
Cloud infrastructure
Network topology
Virtualization software