Zero touch network & Service Management (ZSM)

2022:  major strides marked on the network automation transformation journey

Nurit Sprecher, ISG ZSM Vice Chair

Another exciting year in the AI/ML-powered network automation transformation journey is beginning during which the ETSI ZSM (Zero-touch network and Service Management) group will build on the significant achievements of 2022 – in the context of published specifications/reports, cooperation with SDOs, POCs (Proof of Concept) and the strong momentum created in the industry.

Zero-touch network and service automation are essential to unleash the business potential of 5G and beyond. The ultimate automation target is a largely autonomous operation driven by high-level policies and rules, enabling self-configuration, self-monitoring, self-healing and self-optimization – without further human intervention. 

Automation is not only about technology; it also requires changes in the mindset of people. Trust is a major barrier to adoption and striving to build it requires a continuous learning process. As more automation processes are deployed and operate safely and efficiently, human trust will increase and the requirement for a level of supervision/intervention will diminish. Having native security (e.g. an adaptive secured framework, access control, trustworthiness, data protection) can help to establish confidence and instill trust as the automated processes deliver the intended business outcomes.

The threat surface in the ZSM environment is extensive, firstly due to the openness of the ZSM framework. The framework is modular, extensible and service-based and expands across multiple domains. Its interfaces are open and offer model-driven services. Protecting the interfaces and the management services within and across the domains is essential to ensure the trustworthiness of the ZSM framework. 

In addition, the ZSM services can be produced and consumed by new players coming from diverse industries (e.g. government, vehicle industry, energy, transport, etc.). Each player may require or support different trust levels according to its own deployment/execution environments, security policies and regulations. This variety demands flexible and adaptive security control.  

The ETSI ZSM end-to-end network slicing specification has been released.

Network slicing is expected to become a fundamental enabler for value generation: a $300 billion global revenue opportunity by 2025, according to the GSMA.
It has been designed to support a broad variety of use cases (including the unknown) with extreme requirements, providing tailored network capabilities for each individual service. But building a network that supports tens of thousands of individual slices – all of which can be created and set up, operated, scaled, assured to meet each slice’s service-level agreement (SLA), and torn down at a moment’s notice – presents several challenges.

The accelerated worldwide deployment of 5G networks poses a significant challenge to the way networks and services are created, orchestrated and managed. Full end-to-end automation becomes crucial for the delivery, dynamic adaptation and continuous assurance of the highly diverse services – each with its own broad range of requirements – while still ensuring economic sustainability. In addition, the network’s performance, coverage and capacity should be constantly assured to satisfy the requirements of the active services.

ETSI ZSM group now prepares for the next term of activity.

The ETSI ZSM group was formed with the goal to accelerate the definition of the end-to-end service management architecture, spanning both legacy and virtualized network infrastructure, to enable automatic execution of operational processes and tasks. The pivotal deployment of 5G and network slicing has triggered the need for a radical change in the way networks and services are managed and orchestrated. Full end-to-end automation of network and service management has become an urgent necessity for delivering services with agility and speed and ensuring the economic sustainability of the very diverse set of services offered by Digital Service Providers. The ultimate automation target is to enable largely autonomous networks which will be driven by high-level policies and rules (AKA intent); these networks will be capable of self-configuration, self-monitoring, self-healing and self-optimization without further human intervention. All this requires a new horizontal and vertical end-to-end architecture framework designed for closed-loop automation and optimized for data-driven machine learning and artificial intelligence algorithms.

A major milestone was reached during the summer of 2019 with the publication of GS ZSM 001 (ZSM Requirements), GS ZSM 002 (ZSM Reference Architecture) and GS ZSM 007 (ZSM Terminology).

The Telco industry is heading towards a very interesting phase. Open source (OS) deployments are looking very promising. On the one hand there is the delivery of more flexible, simpler and agile deployments. On the other hand, the success of the current business is based on high quality solutions based on standards. There is no doubt that the success of the Telco industry will not attain the high current level without standards. ETSI, 3GPP, GSMA, etc. have done a great job.

But it is also clear that the way standards are created is evolving and taking on board the best of the open source community methods. An important discussion is how can both camps learn from each other.

Deutsche Telekom hosted a Conference on this topic at DT Headquarters in Bonn, on 9 and 10 September. The conference took place ahead the ETSI ZSM#8 workshop. The supporting organizations were ETSI, Linux Foundation and Telecom TV. Open Source Networking (OSN) Days of Linux Foundation were also embedded into the conference.

The purpose of the event was to discuss the enhancement of the collaboration and cooperation between SDO and OS. ETSI and LFN are good representatives of both parts of the industry. TM Forum (TMF) was invited as well. 

The ZSM#7 meeting was hosted by Intel on 17-21 June, 2019, at their headquarters in the sunny city of Santa Clara, California.

The meeting was highly productive and significant progress was made. In a nutshell, we are now finalizing the work on the ZSM requirements and architecture. The final drafts for approval of these specifications will be available during July 2019 and publication is expected to take place in September. In addition, we advanced the work on the means of automation, end-to-end management and the orchestration of network slicing as well as on the ZSM landscape. We agreed on the skeleton of the end-to-end cross-domain service orchestration and automation specification. Noteworthy is the kickoff of a whole bunch of new work items dedicated to closed-loop automation.

As the end of the year is fast approaching, I’m taking this opportunity to look back at the progress of our work during 2018 and review what we accomplished during the year. Our excellent achievements and the momentum we managed to create in the industry certainly evoke both satisfaction and pride. 2018 was without doubt an amazing year!

The ZSM kickoff meeting took place on January 10-12, 2018, with 30 companies signed as ZSM members/participants. In that meeting we appointed our leadership, agreed on our objectives and approved the creation of five work items: ZSM requirements, ZSM architecture, end-to-end management and orchestration of network slicing, ZSM landscape and means of automation.  Since then we have grown to 65 members/participants (List) and have made tremendous progress in our work thanks to our weekly calls and the additional six face-to-face meetings. We benefited from the fact that ZSM experts come from different backgrounds (e.g. Telco, IT, Enterprise) and strove to bring these worlds together, utilizing the best that each can offer.

Together we managed to look at many business-oriented scenarios and the related automation challenges faced by operators and vertical industries, and succeeded in deriving architectural, functional and operational requirements for an automated end-to-end network with service management. We grouped related scenarios and are now in the final phase of consolidating the requirements.

In addition, we worked hard to develop a ZSM architectural framework (see Figure 1 below) which will enable a zero-touch automated network and service management in a multi-vendor environment. We introduced a set of architectural principles and requirements that guided the design of the architecture. The ZSM architecture is service-based, modular, flexible and extensible. It allows for the integration and composition of management services via an integration fabric. The ZSM framework supports the separation of management and automation into different areas of concern, i.e. network management domains and end-to-end cross-domain service management; both are responsible for fulfillment (orchestration and control) and assurance (data collection, analytics and intelligent automation) within their scopes. Decoupling network management domains from end-to-end cross-domain service management prevents monolithic systems, reduces complexity in the entire service and enables domain and end-to-end management to evolve independently. Every management domain implements a set of capabilities which are exposed via a set of interface end-points.

The architecture supports open interfaces as well as model-driven service and resource abstraction. The management services which are exposed by management domains, including the E2E service management domain, are described and specified. The architecture allows operational data to be kept separate from the management applications, enabling efficient access to data and cross-domain data exposure (e.g. topology, telemetry data) which can be leveraged by network and service intelligence capabilities (e.g. data-driven machine learning, artificial intelligence and other technologies for automation). The architecture is designed to enable closed-loop automation (connecting assurance and fulfillment processes) at the network and service-management levels where the automated decision-making mechanisms (e.g. self-optimization, automated service assurance) can be bounded by rules and policies.

Figure 1: ZSM Architectural Framework

The ZSM Forum @ Layer 123 SDN NFV World Congress 2018 sparked great interest. The importance of the ZSM work, its objectives and approach were once again supported during the highly successful and well-attended forum.

The third ETSI ZSM (Zero touch network and Service Management) forum was hosted by Layer123 at the well-attended SDN NFV World Congress 2018 that took place on October 8, 2018 in The Hague, Netherlands. This year the congress focused on three primary themes relating to ZSM: technology (e.g. cloud native NFV, SDN, security), automation (e.g. zero touch, artificial intelligence, programmable cloud) and business (e.g. 5G, service transformation, use cases).

Klaus Martiny (DT), the ZSM Chair, opened with welcome notes. Klaus reminded the audience that a year ago at the same congress he shared the plan for multiple companies to set up a new initiative, focusing on end-to-end service and network automation, that will address the complexity (in terms of network management) created by the technology evolution. Since then, ETSI was selected as the umbrella for the new initiative and the new Industry Specification Group (ISG) was formed in December 2017. The first meeting of the new ISG took place in January 2018. The ISG has made great progress with the work and is well positioned to facilitate collaboration with relevant open-source projects, standardization bodies and fora to help the industry move to an environment that leverages synergies and achieves alignment through convergence on a single end-to-end network and service management architecture. Cooperation and alignment across the industry are essential to promote the adoption of and alignment with the ZSM architecture and solutions as well as to achieve automated end-to-end network and service management. The ISG ZSM intends to hold an open dialogue with the related organizations and open-source projects so as to encourage mutual convergence. Klaus highlighted the importance of providing early implementations and Proofs of Concepts (PoCs) that can validate the specifications and inject input into the specification work. To this end, he invited the industry players to demonstrate PoCs.

Nurit Sprecher (Nokia), the ZSM Vice Chair, presented (see presentation in ZSM Open Area) the drivers and triggers for full end-to-end automation of network and service management, the rationale for the formation of the new ISG and its goals as well as the work program and status. Currently, the ZSM group includes 59 members/participants of whom 18 are operators.

Nurit also highlighted the important role of PoCs in demonstrating the viability of the ZSM implementations and she invited the different players to join the ZSM PoC projects. The ZSM PoCs are multi-party projects in which network/service providers, suppliers, universities, research centers, open-source projects, integrators and others can participate. The results and lessons learned from the PoCs will be channeled to the ZSM specification work. Nurit pointed to the first ZSM PoC, ServoCloud (see ZSM Wiki) that aims to demonstrate efficient lifecycle and element management automation at scale, and she invited the audience to examine the PoC which was presented during the congress. Nurit concluded that we have just embarked on an exciting journey towards the automation transformation that will help operators to meet user expectations for service agility and create new business opportunities.  Moreover, she emphasized that the ISG intends to drive a highly focused and agile industry effort involving key players spanning the breadth of the ecosystem. The ISG is open to both ETSI members and non-ETSI members. The different players in the value chain are welcome to join the ISG effort, contribute to the development of the specifications and demonstrate PoCs.

Diego Lopez (Telefonica), one of the founders of the ISG ZSM, presented the ZSM scenarios and key requirements which are based on the current content of ETSI Group Specification (GS) ZSM-001. The ZSM scenarios are used to derive the requirements for an automated end-to-end network and service management in general, and to drive the design and specification of the ZSM architecture and solutions. ZSM-001 identifies business-oriented scenarios and related automation challenges faced by operators and vertical industries. The scenarios’ analyses derive architectural, functional and operational requirements. Currently there are 31 scenarios and more than 90 requirements. The ISG is working towards grouping related scenarios and consolidating the requirements. The intention is to outline the key areas for automation and zero-touch operation with the scenario groups and to demonstrate the value and applicability of the ZSM architecture and the management services for supporting future-proof scenarios, such as 5G network-slicing management as well as incremental evolution towards end-to-end automation and zero-touch. The presentation is available in the ZSM Open Area.   

The ZSM interim#1 meeting was hosted by Ericsson on 9-12 July, 2018 at their headquarters in Kista, Sweden, in a meeting room which was named after Hilda, the wife of Ericsson’s founder. The meeting was a good opportunity for the ZSM team to discuss additional scenarios, advance the ZSM architecture work and demonstrate the first ZSM PoC.

As described in great-strides-made-by-technical-brainstorming-at-zsm-3, the ZSM architecture supports the separation of management and automation into different areas of concern, i.e. management domains. At the ZSM interim#1 meeting and in follow-up conference calls, agreement was reached on the high-level architecture inside a management domain (depicted in Figure 1 below). Each domain includes functional components (FCs) that perform specific task(s) and expose one or more management services via service interface(s). Some of the services are internal services and can only be consumed by authorized functional components inside the domain. Other services can be exposed and also consumed by authorized functional components outside the domain (including those contained in the E2E service management domain and the digital storefront). The management services within the management domain are assembled into logical groups, such as domain control services, domain orchestration services, domain intelligence services and domain assurance services. The architecture is designed to enable closed-loop automation (connecting assurance and fulfillment processes) where the automated decision-making mechanisms (e.g. self-optimization and automated service assurance) can be bounded by rules and policies.

The ZSM ISG reached a significant milestone, agreeing on the baseline for the ZSM architecture

The third ZSM meeting was hosted by Huawei on June 04-08, 2018, in the fascinating Chinese city of Shenzhen.

The meeting was particularly special because of the intensive and fruitful ad hoc technical brainstorming that took place during the week, enabling thorough consideration of the requirements, architectural principles and design. By the end of the meeting, the ZSM group had agreed on the baseline for a service-based, end-to-end management architecture (depicted in Figure 1 below). The architecture enables automation at scale and allows all operational processes and tasks – delivery, deployment, configuration, assurance, and optimization – to be executed automatically.

The architectural principles and requirements were agreed on with the aim of shaping the architectural baseline and guiding its further development during the standardization process. The architecture is modular, flexible and extensible. It allows deployments that can be adapted to different volumes of managed entities and/or to various scales of the geographic distribution of these entities. Modules can be independently deployed and scaled. The functional components of the architecture will also be designed for failure – so that management services can cope with failure of themselves and of the infrastructure without or only with modest service degradation.

Figure 1: ZSM Architecture

The second meeting of the ETSI Zero touch network and Service Management (ZSM) Industry Specification Group (ISG) was hosted by Nokia at its Båtvik Training Center in Kirkkonummi, Finland, on March 13-15, 2018.

Forty-nine experts participated in the meeting and more than one hundred contributions were submitted and discussed. The meeting started with key notes presented by Lauri Oksanen, VP Research and Technology at Nokia, on “the automation imperative” to transform economy and society and to create time.

Klaus Martiny, the ZSM ISG Chair, continued with his perspective, highlighting the steady growth of the ISG which has seen a 56% increase since the kickoff meeting. Fifty organizations have already joined the group (see the List of Members and Participants), underlining the importance of the ZSM work for future network and service automation. The fact that the ZSM experts come from different backgrounds (e.g. Telco, IT, Enterprise) is a positive development, since the ISG strives to bring these worlds together, utilizing the best that each can offer. However, this may create a slow start, since all the members need to speak a common language.