How ACL Digital Reimagined Fiber-to-the-Home Architecture for a Tier-1 Telecom Operator
Overview
A leading global telecommunications equipment provider sought to apply Software-Defined Networking principles to fiber access networks, breaking away from rigid, proprietary Optical Line Terminal hardware that had long tied operators to specific vendors. The end objective was to deliver a fully automated, software-defined fiber provisioning platform for one of India’s largest telecommunications operators. ACL Digital was engaged to design and build a decoupled, cloud-native optical access architecture that replaces legacy hardware with programmable white-box terminals and open-source software frameworks, enabling rapid, automated residential fiber provisioning at scale.
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Challenges
Vendor lock-in and hardware rigidity
Traditional Fiber-to-the-Home architectures relied on heavy, proprietary Optical Line Terminal chassis boxes that locked operators into specific vendors and limited operational flexibility
Slow feature rollout
Tightly coupled control and data planes meant that introducing a single new consumer feature or firmware update routinely took several months or longer, significantly limiting market agility
Manual provisioning bottlenecks
Legacy provisioning processes required significant manual intervention, slowing down residential fiber deployments and increasing operational costs
Integration complexity
The new platform needed to integrate seamlessly with an existing, large-scale legacy Network Management System already in production at the operator level
Solution
ACL Digital developed a decoupled, software-defined optical access architecture built entirely on open-source telecommunications frameworks:
- Control and data plane separation: The tightly coupled OLT hardware architecture was decoupled, with complex control plane components abstracted out of the physical box and moved into a centralized software controller, enabling white-box hardware to replace proprietary legacy terminals.
- Voltha integration: The team leveraged Voltha (Virtual OLT Hardware Abstraction), an open-source framework that abstracts the complexities of physical OLT hardware and presents the entire access setup as a standard OpenFlow-programmable switch to the SDN controller.
- ONOS SDN controller: The architecture deployed ONOS (Open Network Operating System) as the core SDN controller, purpose-built by the telecom industry for carrier-grade optical and wide-area access networks to dynamically push provisioning profiles and configurations through the Voltha abstraction layer.
- Microservices orchestration layer: A custom microservices-based orchestration layer was built to integrate directly with the operator’s legacy Network Management System, automatically ingesting residential fiber orders and translating them into configuration commands delivered to the physical white-box terminal without manual intervention.
- CORD architecture implementation: The solution successfully achieved the industry-recognized CORD (Central Office Re-architected as a Datacenter) paradigm, converting a legacy telecom central office into an agile, cloud-native data center environment.
Outcomes
- Faster feature deployment: Feature rollout timelines were reduced from several months to days, giving the operator significantly greater market agility
- Eliminated vendor lock-in: Transitioning to white-box hardware and open-source software removed dependence on proprietary vendors, substantially reducing both capital and operational expenditures
- Fully automated provisioning: Residential fiber connections are now provisioned automatically from order initiation to home terminal activation, with zero manual intervention
- CORD paradigm achieved: ACL Digital successfully transformed a legacy, hardware-heavy central office into a flexible, cloud-native environment, a strong competitive differentiator when engaging Tier-1 telecom operators globally
- Reusable expertise: Hands-on experience with Voltha, ONOS, and open-source optical access frameworks makes ACL Digital a credible partner for any operator seeking to modernize fiber access infrastructure
