How telcos are using opensource software to drive change

Opensource software is a growing part of the telecoms IT and network landscape, with major communications service providers (CSPs) using it to simplify how they implement cloud-native network and IT infrastructure. Yet there are notable differences in telcos’ opensource strategies. 

In the case of Orange “the journey on which we are engaged is to try to support the network vendor to become a software provider,” says Philippe Ensarguet, VP of Software Engineering. Orange would like vendors to support a horizontal operating model that leverages a common telco cloud stack.

“This horizontal approach, is something we have been shaping for two or three years with our partners, and it’s basically a question of the infrastructure we will use from our data center to the private cloud or public cloud, or even at the edge of our networks [to] run the network functions, across the spread of our networks,” he says.

“We are in 2025, and even if telco industry has a sliding window with delay regarding IT, it’s hard to believe we need to deploy an infrastructure for every network function we want to bring to production,” says Ensarguet. “With cloud-native and CNF [cloud-native network function] transformation, we could hope for having a better mutualization and sharing of infrastructures.”  One of the issues the company faced was ensuring that CNFs from multiple vendors would comply with its own private and public cloud infrastructure – an issue that TM Forum’s ODA Canvas addresses for OSS/BSS applications.

“At best there is one vertical tool to do the deployment and the operation; at worst you have almost [separate] tools to deploy and to monitor and operate every service you're buying,” explains Ensarguet. “We are spending a lot of energy implementing dedicated services to manage the specificities of vendors. It's not sustainable, it's not efficient, it's not productive. So, that is the reason why we push for a horizontal model, and we use opensource as a catalyst.”

The factory model

Orange launched its network integration factory in 2022, which is almost completely comprised of opensource components, to “test and validate technical chains, the performance of end-to-end services and to conduct tests with users,” says Ensarguet, drawing on what Orange has learnt from building and running its live test 5G standalone (SA) network, Pikeo. The aim is to apply common IT skills to design and operate applications and network functions, independently of which company supplies them.

Orange is also one of the founding members of Project Sylva, which aims to develop a cloud-native, scalable and energy-efficient telco cloud infrastructure that will support Open RAN, edge computing and AI-driven networks. The company has already implemented Sylva-based network functions and services on 1,600 servers across Europe and Africa, and Ensarguet expects this to rise to 2,000 dedicated servers within the next two years.

“We are building step by step,” he says. “It's super hard to change when you do not have a return on investment on existing infrastructure, but opensource is already very integrated in what we are doing in our networks at Orange, and it will be even more so in the future’.”

Rebalancing relationships

Deutsche Telekom is also seeking to simplify software integration and operation in increasingly complex end-to-end systems and sees opensource collaboration as an important lever for rebalancing the telco / supplier relationship. 

“I do believe that if we start to put all the big telco players together … it gives us as telcos some power in negotiations with other stakeholders in the industry,” says Laurent Donnay, CIO Platforms, Deutsche Telekom. 

“Look at other software vendors that are today selling and offering gateways or middleware,” he adds. “If all of a sudden, we have half of the telco industry that has defined a norm, we're then having different discussions with the software provider.”

Over the last year Deutsche Telekom has made its middleware code, which handles almost 500 million transactions, available in open source “so any other telco could use it, or take the code, increase it, improve it and bring it back”. The company also uses opensource code to build API gateways.

Managed opensource

Opensource software is also integral to Vodafone’s infrastructure software; around 80% or 90% of the code used for infrastructure such as container orchestration, web servers and API gateways, is opensource. 

“Often, it's a question of buying software [that is] managed opensource. Everything runs on Linux, so that's a big part of your infrastructure,” says Dr. Lester Thomas, Head of New Technologies and Innovation at Vodafone Group. 

When it comes to functional software, however, less than 10% of what Vodafone uses is based on opensource, according to Thomas.  

And even if Vodafone is likely to use more opensource code for business support system (BSS) components than it has in the past “our aim isn’t to replace our vendors”, explains Thomas. “I’m humbler than to think we could suddenly build something like a rating engine. That’s very specialist [and] we still see that as being a proprietary thing that you would buy.” 

This is the approach that TM Forum advocates. Indeed, Thomas points to TM Forum’s Open Digital Architecture (ODA) Canvas, to which Orange and Deutsche Telekom also contribute, as an example of how opensource software infrastructure can smooth out the integration and operational issues associated with using proprietary software components.

“Although the ODA Canvas manifesto does not state that the functional components are opensource, we said it runs on an opensource reference canvas infrastructure,” says Thomas.

The Canvas enables software providers to continue supplying what Thomas describes as “black box, proprietary commercial software component” as long as the components integrate and operate seamlessly with the infrastructure underpinning them. In addition, the Canvas can be used to manage non-ODA software applications such as CNFs.

Scale is everything

And as Thomas points out, major vendors are already prolific users of opensource software. Nokia and Red Hat, for example, are members of Project Sylva.  

“Go to any of the vendors today and say: ‘Show me your building materials, what’s underneath your product,’ and it’s all running on the same opensource code,” Thomas says. “So, let’s officially accept that, and let’s collaborate on having only one or a few sets of standards.” 

Omdia analyst James Crawshaw notes there is little incentive for suppliers to encourage extensive opensource development by their telco customers.

“The general pattern is that there is a lot of interest and excitement at the launch of new OS [opensource] projects, but telcos are unable to use them at scale in production networks without outside help,” Crawshaw explains. “Unfortunately, the vendor community usually has a strong interest in telcos continuing to buy their proprietary solutions rather than help them use opensource equivalents.” 

Omdia points out in a research note that one of the issues with opensource development is that “opensource software does not automatically come with a guarantee for support and may even contain bugs. Code stability is critical for telecom applications that demand 99.999% reliability.”

TM Forum has tackled this issue by making it possible for companies, and notably hyperscalers, to develop their own canvases based on the ODA Canvas, which is a reference implementation.

The ODA Canvas aims to simplifiy the integration and management of new cloud-native components from a range of suppliers OSS / BSS applications or cloud-native functions into telcos’ existing IT environments. 

Microsoft, for example, announced with TM Forum an open-source toolkit available in GitHub that makes it possible for telcos of all sizes to build ODA canvases on Microsoft Azure.

Another issue that CSPs face is the need to keep up with the latest iterations of software, which again a commercially supported version of the ODA Canvas is designed to enable.

Otherwise, “as they update their local copies of the software they will need to ensure this remains compatible with the network functions from different network vendors,” states Omdia. As a result, in-house opensource software development is typically beyond the reach of smaller operators that lack armies of developers.

Indeed Ensarguet believes that in-house opensource development makes most sense for telco groups that operate in multiple countries and are looking to standardize operations.

“At the end of the day, when you are a single-country operator the replication, the optimization, the capitalization is less a question as you roll out services.”