Deutsche Telekom taps Adtran for software-defined broadband access upgrade

Deutsche Telekom is making a move towards a disaggregated network for both its fiber and legacy networks by teaming up with Adtran. Over the past two years, Adtran has worked with Deutsche Telekom on the service provider's Access 4.0 program, which includes the use of Adtran's software-defined networking (SDN) tools and its software-defined optical line terminal (OLT) terminal systems.

The move to more cost effective and flexible disaggregated networks has been underway for four or five years now, and Deutsche Telekom's Access 4.0 program is proof that it's getting down to the brass tacks.

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Along the same lines, Adtran announced on Monday that it's working with Orange's software-defined networking (SDN) access renewal and evolution strategy (ARES) program. While Orange and Deutsche Telekom are using different program names, the goal, and some of the gear, is the same.

"Deutsche Telekom is using some of the same components we're going to be using in the Orange agreement, including our OLT and our Mosaic Cloud Platform, and that is the combo that really is important for this," said Adtran Chief Product Officer Dan Whalen. "There are going to be commercial commitments around the current (DT) GPON deployment, as well as their future Access 4.0 deployments that will support both GPON and XGS-PON. All of this will work in this open disaggregated solution."

Other vendors in the Access 4.0 ecosystem, which includes chip makers, virtual routing companies and white box vendors, includeBarefoot Networks, Intel, Edgecore Networks, Radisys, RtBrick and Broadcom.

Currently, Deutsche Telekom has about 33 million homes passed with VDSL today, and only about 1.6 million homes passed with fiber-to-the-home. Deutsche Telekom will start Access 4.0 deployments on GPON "followed fast by XGS-PON," according to Whalen. The cloud-based XGS-PON will allow DT to scale services to 10 Gbps.

"We're already doing demonstrations with them (DT) on the technology," Whalen said. "We're fast down the path of trials and we have another physical demonstration with them next week. We expect to be in a good place for deploying (GPON) with live customers in the first quarter of 2021 on their Access 4.0 infrastructure.

"We do think there's going to be multiple options for them to deploy.There's definitely GPON, there's XGS PON, there's G.fast and all those are options that we support. You could see them leaning towards leveraging the (Mosaic) cloud orchestration platform that we built to support them across the various technologies and trying to make sure that they conform to common management platforms that they use."

With DT's current low-fiber penetration, as well as its affiliations across Europe, the Access 4.0 program has a lot of headroom going forward. The first stage of the Access 4.0 rollout will be targeted at residential, enterprise and backhaul services on DT's fiber access network in Germany. DT is Adtran's largest customer in Europe.

A key pillar of Access 4.0 is the Open Networking Foundation's SDN Enabled Broadband Access (SEBA) platform. SEBA describes how to assemble a collection of open source components to build a virtualized PON network to deliver residential broadband and mobile backhaul. SEBA uses a disaggregated white-box approach for building next generation access networks by using open source. 

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With SEBA, functionality that traditionally ran on chassis-based OLTs and on BNG routers is run in the cloud while the hardware is a collection of white-box OLTs, switches and servers. SEBA blends together the collection of open source hardware and software into a comprehensive platform that exposes northbound FCAPS interfaces, making it easier to integrate a SEBA POD with an operator’s OSS/BSS system.

Access 4.0 also includes ONF’s Virtual OLT Hardware Abstraction (VOLTHA) open source software project, which is a component of SEBA, that abstracts a PON network to make it manageable as if it were a standard OpenFlow switch.

Along with Turk Telecom, DT was one of the original backers for the SEBA reference design. The SEBA reference design is a lightweight version of R-CORD (Residential Central Office Re-architected as a Datacenter.)

While BT, Openreach, AT&T, and Turk Telecom have kicked the tires on SEBA, DT appears to be the first Tier 1 provider that is close to a deployment. AT&T, which contributed VOLTA into the ONF three years ago, Turk Telecom and Telefonica are in trials with the VOLTHA adapter.

"We're working with a number of people that are interested in it, but nobody's using it the same way that Deutsche Telekom is planning to use it," Whalen said of SEBA. "There's been a couple different iterations of the VOLTHA product, and I think DT will probably be the first Tier 1 deployment of what I would refer to as the second version of the VOLTHA adapter."