From enterprise behemoths to those desperately home-schooling, the appetite for cloud-based services shows no sign of faltering. Behind the scenes sit vendors like Nokia, which today unveiled its latest network operating system (NOS), which aims to simplify the process of automating and scaling data centre fabrics.
Nokia Service Router Linux (SR Linux) is a clean-sheet, hardware-agnostic operating system. At the heart of this is a more permissive approach to extensibility, with developers having full access to the underlying OS, as Nokia CTO for IP/Optical Networks Steve Vogelsang explained.
“Typically, inside a network operating system will be a base OS, like Linux. Typically, [Linux] is embedded deep inside the system. It’s not really exposed. And what you get access to is whatever set of APIs and interfaces the switch vendor has decided to expose,” he told El Reg.
This presents a problem for third parties looking to make their own distinct modifications, as they’re effectively chained to the vendor’s release cycle. Should they require a new feature, they’ve got to wait until a patch swims downstream from the vendor. In the same breath, there’s always the chance a vendor may opt to retire a feature, potentially breaking third-party code later down the line.
Nokia’s SR Linux takes a different apprach, exposing the underlying Linux operating system to customers. Applications are built using Nokia’s language-agnostic NetOps Toolkit, and can use the various networking APIs offered, while existing as a distinct and independent entity.
“Suppose you want to write your own routing protocol,” said Vogelsang. “That would be fully operationalized and managed within SR Linux.”
But because third-party applications are independent, it’s possible to manage them without impinging on overall operations. You can, for example, upgrade an application without having to make any sweeping system-wide modifications. Similarly, if the underlying SR Linux OS sees an upgrade, customers aren’t forced to re-compile their code.
“There have been some vendors that tried to enable agents — I think they were called — to run on the switch. And the difference is the way those agents worked. They were a bolt-on on the side and did not become a seamless part of the system.”
Sitting alongside that is Nokia FSP — an automation and operations toolkit for SR Linux, designed to assist in network simulation and planning, as well as deployment.
With the Kubernetes containerization platform at its core, techies can template network fabrics through an integral tool called the Digital Sandbox.
“This creates, in software, an exact replica of a network. We call it a digital twin, and it implements the same software that will run on the network switches themselves, with the exact same configuration for the network design, allowing you to verify the network design will meet the requirements.”
Nokia FSP then automatically generates all the information required for deployment, and on an ongoing basis, handles operations. “Any configuration changes becomes code-driven through FSP. The net of this is what allows a very small team to manage and operate a huge network through the power of software. It’s a software driven type of environment.”
IDC analyst Brad Casemore said: “Generally, Nokia has the right approach: a modular, containerized Linux NOS and a highly automated, open fabric, with telemetry capabilities for cloud-loop operations.”
Casemore added that Nokia would try "to differentiate on the strength of its IP-layer (Layer 3) routing stack", adding: "Data centre networks that support modern cloud applications at scale are built as L3 fabrics, and Nokia clearly felt that its experience and heritage in routing would prove valuable as data-centre switching becomes increasingly predicated on IP routing protocols for simplicity and scale.”
Already, Nokia has been road-testing SR Linux with Apple, which is using the software in its new Denmark data centre. Casemore pointed out that with this effort, the Finnish tech firm is not merely targeting the lucrative hyperscaler market, but also telcos (its traditional bread-and-butter), as well as smaller cloud providers.
“The largest hyperscalers increasingly develop their own network software or leverage open-source NOSes such as [Microsoft's open-switch software] SONiC,” he said. “Nokia might have an opportunity to play at the spine and super-spine layers of those networks.
El Reg notes that Nokia itself became a contributor to the community on chassis-based Software for Open Networking in the Cloud (SONiC) in May, while Dell created its own SONiC distro as well as supporting the software on its switches.
Of Nokia's SR Linux, the IDC's Casemore said the Finnish firm was "likely to see more traction initially with telco clouds, because they already have relationships with those customers and those customers are keen to modernize their data centre and edge environments,” he opined.
Casemore added that Nokia "might also make some headway with the Tier 2/3 clouds, but it’s a competitive space, inhabited not only by OEM competitors such as Cisco, Arista, and Juniper, but also bare-metal switches from white-box ODMs.” ®