IP/Optical convergence has been looked at as a critical piece of network providers’ IP network modernization strategy
The enterprise network was once the hive of business activity with the goal of providing workers with quick, low-latency access to business applications. The residential network would then take the bandwidth burden during residential “peak hour” to allow for streaming, gaming and other non-business activities.
But the market has shifted dramatically, with traffic flows moving toward the home to support remote work, gaming, e-learning and more. Meanwhile, enterprises accelerated their digital transformation and moved quickly to embrace Virtualized Network Functions (VNFs) and cloud applications, including Software-Defined Wide Area Network (SD-WAN), to reduce costs.
Network providers have done an admirable job keeping up with this shift, but it is clear that residential networks are now taking the majority of the bandwidth burden, while the enterprise network has seen a considerable drop-in activity.
As a result, network providers are currently evaluating how to streamline these enterprise and residential networks to achieve a more cost‑efficient, resilient and unified offering. As part of that, IP/Optical convergence has been looked at as a critical piece of their IP network modernization strategy. Research developed by Heavy Reading and Ciena found that as many as 87% of providers are looking at this convergence as important or critical for their next-gen networks1.
The edge is driving a concerted convergence push
A key challenge of traditional access, aggregation and metro networks is their static design. Residential and Enterprise networks were often built as entirely separate networks because they were designed to support different service types and Service Level Agreements (SLAs). Traffic in both networks would flow through their respective access and aggregation portions and then onto the metro core. At some point the two types of traffic would converge with much of the combined traffic ultimately destined for the internet and cloud providers. This traditional approach to network architecture makes it challenging to provide consistent services between residential and enterprise customers and allows bandwidth to become stranded as traffic patterns change. It becomes very difficult to create new services or to deploy applications closer to end users. Legacy networks continue to prove themselves too rigid to support next-generation distributed services and applications. Without adequate network automation and hardware programmability, the network can take hours, to days, to weeks to respond to changes.
IP/Optical convergence is a way to address these challenges, reduce network hardware and lower costs for the network provider. Convergence at its most basic is the streamlining and simplification of networking layers that include optical (Layer 0) up to an including IP (Layer 3). In a converged architecture, it is possible for the principles of Adaptive IP to be utilized so that one network element can now do the work of what would have taken two or three network elements in a legacy architecture.
From a hardware perspective, continued innovations in Digital Signal Processing (DSP) and the miniaturization of electro-optics are enabling the integration of coherent optics in router platforms through compact coherent pluggables. Data transport across distance is achieved via photonic line systems, delivering the right flexibility and cost for the specific use case in the network. And in this new world where the network needs to be more programmable and automated than ever before, integrated intelligence in these platforms is important to simplify service turn-up and operations.
Service providers are investigating IP/Optical convergence now more than ever, however, no two networks are created equal. Every operator comes with their own unique history, configurations, topology and operational requirements. It is this reality that makes a one-size-fits all approach for convergence nearly impossible.
How to get started on the convergence transformation
The biggest challenge service providers face in moving to a converged IP/Optical end-state architecture is the operational complexity and technical debt of their current network. Very few network providers have the luxury of a clean-slate network environment — but it’s a hurdle that can be navigated.
Providers can consider four key activities to start to progress towards a converged IP/Optical network:
- Optimize the network through software, using a centralized multi-layer domain control to optimize service quality, capacity and network resources across IP and Optical layers. While Multi-layer IP and optical layer controller deployments are relatively nascent, deployment is expected to accelerate over the next year. According to the Heavy Reading research, 39% of respondents expected a multi-layer controller deployment by the end of this year, with that number exploding to 88% by end-2022.
- Introduce new, more cost-efficient coherent optic technology, including pluggables, in existing transport equipment or on new ‘coherent-designed’ routers as they are deployed in the network.
- Deploy a suitable photonic line system as the network is upgraded, which requires selecting one open and flexible enough to scale to new sites and is right-sized to suit the needs of both today and tomorrow; and
- Continue with the architecture changes as the business cases justify transforming the various parts of the network such as access, aggregation and metro.
How network providers proceed to execute these activities is based upon their unique requirements. Sometimes we see competitive pressure driving a rapid transformation towards converged IP/Optical leveraging all four activities. Other times we see partial evolutions. But there is no ‘one-size-fits-all’ approach to convergence.
Modernizing the network in this way may seem daunting, but it’s necessary. In the new networking environment, software control, automation and analytics are no longer nice-to-haves; these elements are needed to enable successful network transformation. Software convergence involves multivendor, multi-layer management and resource optimization through a unified interface that enables planning, fault correlation, service resiliency and capacity optimization.
The world has moved on from the old networking architectures quickly and in many cases permanently. Ultimately, the network providers looking at a streamlining of their networking layers are likely to mitigate revenue declines while enabling a consistent, seamless user experience regardless of location.
[1] Source: Heavy Reading, “IP and Optical Convergence Survey”, May 2021, n = 220
