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SEBA/VOLTHA: SDN-Enabled Broadband Access Projects – A Year in Review (Part 1)

Dec 17, 2021
Andrea Campanella
Andrea Campanella About the author

This is part one of a two part blog about the ONF’s SDN-Enabled Broadband Access (SEBA) and Virtual OLT Hardware Abstraction (VOLTHA) projects, which have been successfully deployed commercially for broadband access by Tier 1 operators. This blog offers an overview of the current status of SEBA and VOLTHA as we end of 2021; the second blog will provide visibility into community plans going forward.

ONF Broadband projects consist of SEBA - the reference design for building open disaggregated broadband solutions, and VOLTHA - an open source implementation of the most critical components of the SEBA design. Further background on these broadband projects can be viewed in this Wiki.

ONF’s SEBA project, with its open-source, highly innovative fully disaggregated and cloud native architecture, has had significant impact since its creation about 4 years ago, and now boasts two tier-1 operators, Deutsche Telekom and Türk Telekom in deployment with some of the critical components of the project - VOLTHA and ONOS. The ecosystem of aligned vendors has released SEBA/VOLTHA based commercial solutions with good success, and are actively engaging with operators around the globe. New production deployment at large operators of these solutions is expected in the near future.

Reference Design (SEBA)
The ONF Operator Partner-led reference design team (RDT) have released two detailed versions of the SEBA Reference designs (Rev 1.0 and Rev 2.0). The SEBA RD provides a description of the architecture, building blocks and interfaces, both northbound and southbound for the disaggregated broadband solutions. The APIs include service provisioning, device configuration, inventory, management and FCAPS. Currently the  RDT is focused on putting together a collaboration with the Broadband Forum alongside wt-477,413 and 434, focusing on the interfaces of the disaggregated OLT, with the aim of seamlessly integrating VOLTHA into CloudCO should operators have that requirement. Another area of focus are architecture considerations for SD-BNG.

Disaggregated OLT solution: VOLTHA and ONOS
VOLTHA, SEBA’s most commonly adopted component, is the first open source fully disaggregated, cloud native, broadband solution that has been deployed in production with Tier-1 Operators. With VOLTHA, ONF opened up the broadband hardware and software market, providing a unified OAM abstraction: vendor - and technology agnostic (GPON, XGSPON, EPON) handling of multi-service subscriber provisioning and device management tasks, such as service lifecycle, device lifecycle (including discovery, upgrade), system monitoring, alarms, troubleshooting, security, etc. VOLTHA supports multiple services e.g., high speed Internet access, video on demand, voice over IP, multicast, and a multitude of control protocols, EAPOL, DHCP, PPPoE, IGMP.

Integration of multiple operator workflows is provided by VOLTHA directly out of the box, specifically for AT&T, Deutsche Telekom and Türk Telekom, and since VOLTHA 2.9, Telecom Italia, each with their own unique requirements. All the features and requirements are met in a system that scales to the operator’s requirements (10,240 ONUs in a pod) and also meets setup performance requirements, taking less than 10 minutes from a disconnected OLT to establishing 1024 subscribers provisioned with flowing traffic. The system is also reliable and failure tolerant, when a component of the VOLTHA/ONOS control software fails there is no dataplane impact for the users and the system automatically recovers.

VOLTHA provides a fully compliant OMCI stack, based on the openOMCI standard, thus moving away from vendor dependent implementations, allowing best of breed selection of OLTs and ONUs, independently of one another.

Moreover, VOLTHA leverages a microservice architecture based on docker images on kubernetes, allowing for ease of deployment, upgrade, iterative development and bugfixes.

Finally, through an extensive certification program offered by the ONF, vendor hardware can be certified as compatible with VOLTHA, providing assurances to operators as they shortlist equipment for their network, both OLTs and ONUs.

SEBA/VOLTHA Accomplishments
VOLTHA and ONOS entered production deployments with two major Tier 1 operators, Deutsche Telekom and Türk Telekom.

The ONF operator-led reference design team (RDT) released v2.0 of the SEBA RD in March of this year.

VOLTHA v2.8 Long Term Support (LTS) was released in June 2021, committing to a support timeline of 18 months with test and bug fixes, giving confidence to operators in their production deployment expansion.

Through VOLTHA, a PON network upgrade path is offered to the operators. VOLTHA can be deployed on existing OLTs with adapters, while the network is getting upgraded to newer OLTs. Moreover technology agnostic VOLTHA northbound APIs allow the deployment of combo-PON OLTs and, depending on customer needs, leverage GPON or XGS-PON technology in the same box.

With VOLTHA, the broadband industry has low cost options, both from a CAPEX and an OPEX point of view. This helps support expansion into new markets and support the ever growing demand for fiber connectivity.

Through VOLTHA we have seen a tremendous expansion of the white box OLT market, with many vendors now offering such OLTs as part of their portfolio, lowering the cost of equipment and enhancing the quality at the same time.


To learn more about what’s coming next in 2022 and beyond, check out the next blog.

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ABOUT THE AUTHOR Andrea Campanella
Andrea CampanellaMember of Technical Staff
Andrea joined ONF in October 2015 as a Research Scholar Intern. Andrea received a Bachelor’s degree in Digital Communication and is majoring in Computer Science at the Public University of Milan, Italy, with a focus in computer networks and SDN technology. At ONF, Andrea is on the ONOS core development team focusing on southbound architecture, protocol integration and driver subsystems. Andrea is also part of the A-Team: the ambassador program steering team and is active in shaping the ONOS community. In his free time Andrea enjoys photography, hiking, sailing, biking, and playing basketball.