As consumers of networking services automate their homes, businesses and manufacturing processes in the evolution of Industry 4.0 and Society 5.0, they will require customisable digital services — i.e. carrier-grade cloud-based services — that are available on-demand from their network service providers. To match these evolving demand dynamics, network operators will need to conduct their own digital transformation. Network automation is a must.
The increasing connectivity and complexity of these networks will require network automation to cost-effectively scale operations and meet evolving demands for service quality, reliability and agility. But, what does that look like?
To achieve the agility and economics of web-scale IT technologies, network operators are adopting a DevOps culture, re-architecting central offices as data centers and introducing carrier-grade cloud-based service models. To deliver cloud-based services that can meet carrier-grade performance and reliability standards, they must maximise IT and IP synergies. Only in this way can they truly become digital service providers.
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A massively scalable, highly programmable network fabric is key — network automation
This digital transformation will require a smart network fabric that is massively scalable and highly programmable, which cloud-based services can provide. Network service providers will need to disaggregate and virtualise network functions for increased service velocity, while reducing hardware dependencies by using commodity IT platforms —without losing the inherent security and integrity of purpose-built network appliances.
To achieve this perfect union of IP and IT, network operators must overcome the operational barriers that historically divide these domains. They must harmonise disjointed service policies, resolve a mismatch of interworking protocols and integrate islands of automation to achieve carrier-grade cloud-based services. The ultimate goal is to deliver virtualised services using thousands of network slices over a unified transport underlay network.
The impact of the carrier-grade service cloud
The matching of diverse application needs with end-to-end service delivery guarantees must occur automatically, creating network automation.
This requires orchestrating and inter¬connecting physical and virtualised network functions that are distributed over hundreds of regional and centralised data centers, which collectively form the carrier-grade service cloud. It also includes automatically engineering the necessary data path connectivity in the appropriate network slices for each service.
What is required is to create network automation is an intelligent network functions interconnect fabric that can dynamically deploy distributed telco resources across the wide area network (WAN) to support the overlay slices for carrier-grade cloud-based services. The fabric will need to leverage proven technologies and best practices to solve this issue.
Acquiring topology information: the role of multiprotocol border gateway protocol, SLA and segment routing
To acquire topology information from the virtualised service overlay (e.g., IP/Ethernet VPNs), as well as the IP/Multiprotocol Label Switching (MPLS) transport underlay, a unified routing control plane is required, such as Multiprotocol Border Gateway Protocol (MP-BGP). BGP offers tremendous scale and versatility and is the principle routing protocol used on the Internet.
Overlay service characteristics are captured in policy abstractions that map overlay service level agreement (SLA) policies on appropriately engineered network slices in the underlying WAN. For instance, the SLA requirements for a network function interconnection might be expressed as abstract policy colors, such as low latency, high availability and guaranteed throughput. The process of mapping network functions interconnections is done by a path-computation element, which is effectively a software defined network (SDN) controller that engineers optimal inter-domain segment routes across the WAN using Segment Routing (SR). Pre-defined segment routing templates match the abstract SLA policy colors to specify the various delivery constraints.
Segment routing is an extremely scalable source-based routing technology for engineering dynamic service tunnels. It features fast restoration options that meet deterministic bandwidth, latency and path diversity constraints. SR implicitly supports load-balancing of traffic over all available links that meet the route policy. Additionally, it supports various data path implementations including MPLS and User Datagram Protocols for seamless, end-to-end connectivity between distributed edge and core data centers across the WAN, making it integral for carrier-grade cloud-based service models.
Due to node or link failures, maintenance activities or network congestion, certain traffic engineering characteristics of the underlying IP transport network may potentially impact the SLA conformance of an overlay service. For SLA assurance, the SDN controller will therefore collect real-time traffic engineering metrics, conduct periodical latency measurements of SR service tunnels, and dynamically resize or re-optimizes segment routing paths as needed. If network service functions or workloads are moved between data centers in cloud-based services, the SDN controller will automatically receive MP-BGP updates and adjust underlay transport connectivity as needed.
Automation: a network necessity
Where we go from here: the implications of this new, intelligent approach to interconnecting network functions
This new intelligent approach to interconnecting network functions establishes a dynamic, seamless and automated connectivity model that makes networks highly consumable for carrier-grade cloud-based services. It also helps connectivity service providers on their digital transformation journey — turning their networks into agile, scalable and highly efficient digital service clouds by overcoming the operational barriers and interworking issues between data centers and the wide area network.
The transformative changes of the digital era of cloud, the Internet of Things (IoT) and 5G technology have a profound impact on how networks are designed, operated and consumed. The evolving needs of Industry 4.0 and Society 5.0 will dramatically extend the focus and scope of consumer, enterprise and industry applications, as well as drive orders of magnitude higher capacity, connectivity and efficiency demands through the use of carrier-grade cloud-based services.
Arnold Jansen is a Senior Product Marketing Manager, Nokia
