Automation of Network Services for the Future Internet

Introduction

According to the Internet world stats described in (Hootsuite & We Are Social, 2021), the number of Internet accesses has reached almost 5 billion during the last decades. This massive growth of accesses and Internet applications has brought an increasing unstoppable demand for bandwidth among consumers, fostered even more by the irruption of new technologies such as Internet of Things (IoT), enhanced mobile broadband, or 5G, which ambitions to augment even more the number of industrial applications to make use of the available infrastructure with more stringent requirements.

Many Service Providers (SPs) had to explore different alternatives to satisfy the (fast-changing) customer expectations and create new business opportunities beyond the “traditional” connectivity. At the same time, they need to offer competitive prices and maintain the robustness required to withstand possible Network failures. All this while the Average Revenue Per User (ARPU) remains “quasi” stable (if not decreasing) since the customer base has remained constant in most of the market segments and the new income has been derived to the over-the-top applications. Thus, to remain viable in a highly competitive market, the deployment of convergent IP networks with programmable interfaces for the automation of day-to-day tasks in the network and the ability to develop new network services in a short time has been considered an essential target for Service Providers.

In order to trigger the 'network of the future' and move the whole industry to a new era, the emerging technologies that are considered as the building blocks by SPs are Software-defined networking (SDN) in combination with Network Function Virtualization (NFV) and Machine Learning technologies. The “promise” of these technologies is to allow SPs to program their networks with the agility of the IT industry instead of the old-school slow pace of the telecom industry. However, nowadays, no SP has entirely changed how the transport network (the infrastructure that moves the bulk of the traffic) is operated. Nevertheless, according to Research and Markets (2020), SDN has been one of the fastest-growing markets in the Communications industry, reaching 13.7 million in 2020.

SDN, as described by ONF in (ONF TR-502, 2014) and IRTF in RFC 7426 (Haleplidis et al., 2015), relies upon a modular architecture, focused on the capabilities offered by a computation logic (a.k.a., SDN controller) to separate the control plane from the data plane. The SDN controller is the key element to interact with equipment and systems (Operational Support Systems (OSS) and Business Support Systems (BSS)) through data-driven programmatic Network Application Programming Interfaces (APIs). The definition/usage of these network APIs is the base of the whole network automation approach mainly for the following reasons:

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  The less human intervention for the day-to-day tasks and the reduction of management touchpoints due to single network control points.

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  The controller can run offline tasks to make network resources optimization continuously; this can derive in faster and on-demand provisioning.

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  The standardized interfaces usage reduces the vendor dependency, without completely removing it, and thus allows to customize features as applications.

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  The controller can make advanced traffic steering policies and sophisticated service-aware management.

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  Each API can be considered as an application; these applications can share network information to make advanced decisions.

To facilitate the automation of service delivery procedures in multi-vendor networking environments and make these network APIs reusable, Standard Definition Organizations (SDOs) like the IETF and industry for a such as OpenConfig have defined a set of protocols (NETCONF, gNMI, BGP-LS, etc.) and vendor-agnostic data models. In combination, they can be used to cover the planning and operation needs of a carrier. However, there is a continuous need to standardize new service types or cover new functionalities, which has led to the publication of several standards and specifications by SDOs and Industry fora, such as ONF, IETF, OpenConfig, or the Metro Ethernet Forum (MEF). Thus, some initiatives are based on a gradual adoption of standards and/or the evolution of legacy network architectures to take advantage of more agile and automatic deployments.