Monday, December 19, 2022

Blueprint: Building wholesale networks with OTN

by Chris Janson, Product Marketing Manager, Optical Networking

As we ring in the new year, the transformation of business digitalization continues. We see enterprises increasingly dependent upon networks of highly connected devices and systems to control everything from customer transactions to just-in-time manufacturing. About a year ago, IDC outlined its predictions for 2022 digital transformation. In their report, they foresaw 50% of organizations had transformation plans in place by the end of 2022, and a year later, 90% of organizations would be prioritizing investments in digital tools that augment physical facilities. 

These things come as no surprise to those watching enterprises and their use of technology. Large retailers like Amazon continue to invest in regional warehouses with highly automated inventory control systems. Governments continue to roll out digital systems to control things like municipal parking lots and tax payments. Driving this adoption is the desire to provide better service at lower cost, taking advantage of enabling technologies such as IoT devices and handheld computing power in nearly everyone’s hands (i.e., your smartphone). The result is far-flung entities and their digitalized operations have one thing in common: the need for highly reliable and secure network connectivity. 

Implications for network connectivity

A common thread through any enterprise’s digitalized architecture is the need to connect independent devices and compute or storage capacity. This network aggregates mobile and IoT wireless devices onto an IP-optical wireline network. Modern cellular architecture offers high capacity, low latency, and very resilient performance which must be matched by the backbone network. At layer 3, IP-MPLS routing offers a powerful ability to steer traffic flows exactly where needed and while router capacity continues to grow in pace with demand, there will be a need to perform multiplexing and switching at lower network layers, in the physical backbone network. 

This backbone network needs to be capable of scale and capacity growth matched to the needs of the enterprise. Thirst for capacity has been expanding exponentially for years, demanding that IP-optical networks expand correspondingly. This need for scale has been met through higher capacity routing as well as higher capacity DWDM optical transport systems. Fiber capacities now commonly exceed 400Gbps per wavelength, with some systems now exceeding 1Tbps per wavelength. 

Line capacity is but one performance metric. Service providers must also consider the need for service flexibility, assurance, and security. Flexibility delivers various service protocols and speeds needed by each customer while ensuring performance at defined service level agreement tiers. At the same time, the service must be highly resilient to outages. The service also needs to be secure from theft and intrusion. Some large enterprises will insist that their traffic is logically, if not physically, separated from other user’s traffic. Encryption needs to be provided at the transport layer, which is safe from harvest now, and decrypt later attack in the presence of a practical quantum computer. 

Opportunity for service providers: retail or wholesale

These elements form simple requirements that a service provider needs to meet to enjoy a sizable market share in providing differentiated services to various enterprise customers. For the typical communication service provider (CSP), the question becomes: should they operate as a retail provider or partner with another provider as a wholesale provider? 

For reasons from regulation to the practicalities of customer support, a CSP may decide to set up as a wholesale service provider, working with a retailer to provide last-mile connectivity and customer support for local enterprise markets. This is a very practical solution that can help the CSP capture revenue which otherwise may be lost. Optical transport technology makes this business arrangement very practical to deploy and operate. 

OTN makes it practical

Optical Transport Networking, standardized in ITU-T G.709, provides a set of tools that service providers can deploy to help their wholesale business operate seamlessly. An Optical Transport Network (OTN) is ideally suited to provide an end-to-end solution for various service requirements that demand security, scalability, low latency and high availability. OTN improves network efficiency and utilization and can carry any traffic type including legacy services. The enhancement includes components common to DWDM systems – transponders, optical mux/demux modules, amplifiers – but OTN adds switching and grooming capabilities at layer 1. Multilayer optimization is achieved by using an optimal mix of electrical grooming and photonic transport for increased scalability and flexibility.

OTN incorporates coherent electro-optics to optimize reach and capacity over large metro, regional and long-haul networks as well as to scale solutions in the core. At the network edge, OTN solutions need to be compact, versatile and extend services all the way to customer premise sites to provide carrier-grade service demarcation with end-to-end service assurance. Modern OTN networks provide advanced control plane options for carrier-grade restoration and protection and are managed by advanced network automation and management tools.

In delivering a high-value, SLA-aware solution, OTN offers powerful yet practical tools for premium wholesale and business services with flexibility, security and guaranteed performance. The business services can span from network edge through metro aggregation and core for end-to-end connectivity. OTN delivers efficient aggregation and multiplexing of services that avoids cascading and complexity while supporting any topology mesh with fast service rollout. OTN services are flexible, with client interface and protocol versatility, using any-to-any service connectivity, and SLA-aware provisioning. OTN services are also reliable, with multi-failure restoration, secure through hard traffic isolation within the OTN payload, guaranteed latency and deterministic bandwidth. 

As one example, the use of OTN in a wholesale network allows the operator to slice capacity in any optical line among various user classes, each with its SLA. Traffic slices can be isolated appropriately from each other, using a combination of layer 2 switching for soft isolation and layer 1 OTN for hard isolation within the same optical data unit (ODU). An example of this is shown in figure 1, where various sub-rate services are soft-isolated within ODUFlex 1, while the entire ODUFlex 2 slice is hard-isolated from the rest of the ODU4. This way, the end user performance is ensured as determined by their respective SLAs. 

A service provider who deploys an end-to-end OTN solution is well-positioned to deliver the range of connectivity services demanded by modern enterprises. Whether operating directly with the enterprise, through a retail service provider, or a combination of both routes to market, OTN helps service providers optimize their market share and revenue.

About the author

In his current role with Nokia, Chris Janson follows trends in optical networking technology and their application to finance, healthcare, utilities, government and educational customers. Mr. Janson has been a speaker at many conferences including Interop 2014, Internet2 annual technology meetings, and a 2015 series of executive forums sponsored by CenturyLink and CIO magazine. 

He has also shared his work through many webinars, written publications, on-line videos and articles. Mr. Janson also serves on the boards of directors of the Rural Telecommunications Congress and the non-profit OpenCape Corporation. He holds an MBA from Boston University and Bachelor of Science in engineering from Wentworth Institute of Technology.