ETSI NFV Release 3: update on protocols and data model specification outcomes

2020 turned out to be an unexpected year, with the COVID19 pandemic adversely impacting the “normal” day-to-day lives of humans across the globe. However, even during this turn of events and unforeseen testing times, communication networks demonstrated their efficacy in keeping people and businesses connected. More concretely, Network Functions Virtualisation (NFV) proved its feasibility by enabling the operators to gracefully manage high demand for network connectivity.

NFV blog evolution new vision imageUndaunted by this situation, the technical experts at the ETSI ISG NFV continued to work tirelessly developing and delivering specifications that help get and keep “everyone/everything connected”. And the hard work paid off as ETSI ISG NFV delivered during the second half of 2020 new and updated "protocols and data model" (stage 3) specifications incorporating NFV Release 3 features.

The experts in the Solutions (SOL) working group completed stage 3 work on a subset of the NFV Release 3 features. One of the first features that was already finalised in 2019 was "Management of NFV-MANO" (FEAT11) with the release of ETSI GS NFV-SOL 009 V3.3.1. This document specifies a set of RESTful protocols and APIs that can be used to manage different aspects regarding configuration, performance, fault and logging of entities implementing specified NFV-MANO functional blocks. The defined APIs leveraged the same RESTful principles used for NFV-MANO APIs in Release 2, i.e., the ones used for managing VNF instances, NS instances and on-boarding VNF Packages, NSDs and other artefacts.

New outcomes on the development of NFV-MANO APIs continued in 2020 with the release of ETSI GS NFV-SOL 011 V3.3.1, which specifies NFV-MANO APIs related to management across "NFV-MANO administrative domains" (FEAT08). These APIs are produced by the NFVO and allow different administrative domains to communicate over the Or-Or reference point to help coordinate the management of NS instances deployed on their respective administrative domains. The Or-Or reference point is set in between NFVO instances placed on different administrative domains, as specified in ETSI GS NFV-IFA 030. For instance, the APIs of ETSI GS NFV-SOL 011 enable reusing an NS instance deployed on a domain A and nest it into another NS instance deployed on a domain B. Due to the functional similarities with existing capabilities offered by the NFVO to other systems such as OSS/BSS, most of the APIs are identical or based on those specified in ETSI GS NFV-SOL 005.

The release of new API specification documents was completed in 2020 by the ETSI GS NFV-SOL 012 V3.4.1 "NFV; Protocol and Data Models; RESTful protocols specification for the Policy Management Interface". As its title hints, the document specifies a new NFV-MANO API based on RESTful principles that can be used for setting up a "Policy management framework" (FEAT07). The API, produced by the NFV-MANO functional blocks, offers the much needed management capabilities by the network operators to be able to transfer, update, delete, activate, de-activate policies, and subscribe to and get notifications related to policy management. Note that the specification of the data models and formats of the policy content is not within the scope of this document. Information and data modelling work on policy content is under development as part of the Release 4.

Other Release 3 features did not require creating new specification documents for the APIs, as the existing documents associated to the internal or external reference points of NFV-MANO were already the appropriate placeholder for their specification. Thus, such features were implemented by extending the existing Release 2 specifications with the new functionality and capabilities resulting in the creation of Release 3 versions. The documents that evolved with new features were ETSI GS NFV-SOL 002 V3.3.1 on "RESTful protocols specification for the Ve-Vnfm Reference Point", ETSI GS NFV-SOL 003 V3.3.1 on "RESTful protocols specification for the Or-Vnfm Reference Point" and ETSI GS NFV-SOL 005 V3.3.1 on "RESTful protocols specification for the Os-Ma-nfvo Reference Point". Examples of features in this group included "VNF snapshotting" (FEAT15), "Host reservation" (FEAT04), "VNF software modification" (FEAT02), and "Management and connectivity of multi-site services" (FEAT10). Due to the large amount of specification items, some of these features were partially completed on a subset of workable functionality, and further work is currently ongoing for future revisions of the relevant specifications.

As in many cases during the development of Release 2, some of Release 3 features also required updating the specifications used for the "design phase" parts of NFV, namely VNF, NS and PNF descriptors and artefacts such as VNF Packages. For instance, ETSI GS NFV-SOL 001 V3.3.1 "NFV descriptors based on TOSCA specification" and ETSI GS NFV-SOL 006 V3.3.1 "NFV descriptors based on YANG specification", compared to its latest Release 2 version, added support for describing VNF capabilities related to "VNF software modifications" (FEAT02), "Management of Network Services and connectivity" (FEAT10), "VNF snapshotting" (FEAT15) and "Service availability level (SAL)" (FEAT16). "VNF snapshotting” feature was a particular case, for which a new document had to be created to specify the structure and format of the "VNF snapshot packages". The document was published in its first version as ETSI GS NFV-SOL 010 V3.3.1 "VNF Snapshot Package specification". Other documents that were evolved into Release 3 versions but did not require adding specific support for Release 3 features were ETSI GS NFV-SOL 004 V3.3.1 "VNF Package and PNFD Archive specification" and ETSI GS NFV-SOL 007 V3.3.1 "Network Service Descriptor File Structure Specification".

The Release 3 Description provides more details on the feature scope and the impacted documentation, including not only the stage 3 outputs, but also the stage 1 and stage 2 work outcomes.

Special thanks go out to all the Rapporteurs of the new and existing specifications and to all the companies that supported in the completion of this work in Release 3. The work delivered in 2020 represented a first step in delivering the eagerly anticipated specifications to support new Release 3 features and represented the culmination of the work ETSI NFV started in May 2016 with the opening of study work items for Release 3. However, the work is still not fully complete, and we are expecting the release of the remaining Release 3 features work during the first months of 2021.

Stay tuned for future updates, but above all, “stay safe and healthy”.

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