The service providers leading the Open Networking Foundation (ONF) will publish open designs to address next-generation networking needs.
The ONF service providers - NTT Group, AT&T, Telefonica, Deutsche Telekom, Comcast, China Unicom, Turk Telekom and Google - are taking a hands-on approach to the design of their networks after becoming frustrated with what they perceive as foot-dragging by the systems vendors.
“All eight [operators] have come together to say in unison that they are going to work inside the ONF to craft explicit plans - blueprints - for the industry for how to deploy open-source-based solutions,” says Timon Sloane, vice president of marketing and ecosystem at the ONF.
The open-source organisation will develop ‘reference designs’ based on open-source components for the network edge. The reference designs will address developments such as 5G and multi-access edge and will be implemented using cloud, white box, network functions virtualisation (NFV) and software-defined networking (SDN) technologies.
By issuing the designs and committing to deploy them, the operators want to attract select systems vendors that will work with them to fulfil their networking needs.
Remit
The ONF is known for such open-source projects as the Central Office Rearchitected as a Datacenter (CORD) and the Open Networking Operating System (ONOS) SDN controller.
The ONF’s scope has broadened over the years, reflecting the evolving needs of its operator members. The organisation’s remit is to reinvent the network edge. “To apply the best of SDN, NFV and cloud technologies to enable not just raw connectivity but also the delivery of services and applications at the edge,” says Sloane.
The network edge spans from the central office to the cellular tower and includes the emerging edge cloud that extends the ‘edge’ to such developments as the connected car and drones.
The operators have been hopeful the whole vendor community would step up and start building solutions and embracing this approach but it is not happening at the speed operators want, demand and need
“The edge cloud is called a lot of different things right now: multi-access edge computing, fog computing, far edge and distributed cloud,” says Sloane. “It hasn’t solidified yet.”
One ONF open-source project is the Open and Disaggregated Transport Network (ODTN), led by NTT. “ODTN is edge related but not exclusively so,” says Sloane. “It is starting off with a data centre interconnect focus but you should think of it as CORD-to-WAN connectivity.”
The ONF’s operators spent months formulated the initiative, dubbed the Strategic Plan, after growing frustrated with a supply chain that has failed to deliver the open-source solutions they need. “The operators have been hopeful the whole vendor community would step up and start building solutions and embracing this approach but it is not happening at the speed operators want, demand and need,” says Sloane.
The ONF’s initiative signals to the industry that the operators are shifting their spending to open-source solutions and basing their procurement decisions on the reference designs they produce.
“It is a clear sign to the industry that things are shifting,” says Sloane. “The longer you sit on the sidelines and wait and see what happens, the more likely you are to lose your position in the industry.”
If operators adopt open-source software and use white boxes based on merchant silicon, how will systems vendors produce differentiated solutions?
“All this goes to show why this is disruptive and creating turbulence in the industry,” says Sloane.
Open-source design equates to industry collaboration to develop shared, non-differentiated infrastructure, he says. That means system vendors can focus their R&D tackling new issues such as running and automating networks, developing applications and solving challenges such as next-generation radio access and radio spectrum management.
“We want people to move with the mark,” says Sloane. “It is not just building a legacy business based on what used to be unique and expecting to build that into the future.”
Reference designs
The operators have identified five reference designs: fixed and mobile broadband, multi-access edge, leaf-and-spine architectures, 5G at the edge, and next-generation SDN.
The ONF has already done much work in fixed and mobile broadband with its residential and mobile CORD projects. Multi-access edge refers to developing one network to serve all types of customers simultaneously, using cloud techniques to shift networking resources dynamically as needed.
At first glance, it is unclear what the ONF can contribute to leaf-and-spine architectures. But the ONF is developing SDN-controlled switch fabric that can perform advanced packet processing, not just packet forwarding.
The ONF’s initiative signals to the industry that the operators are shifting their spending to open-source solutions and basing their procurement decisions on the reference designs they produce.
Sloane says that many virtualised tasks today are run on server blades using processors based on the x86 instruction set. But offloading packet processing tasks to programmable switch chips - referred to as networking fabric - can significantly benefit the price-performance achieved.
“We can leverage [the] P4 [programming language for data forwarding] and start to do things people never envisaged being done in a fabric,” says Sloane, adding that the organisation overseeing P4 is going to merge with the ONF.
The 5G reference design is one application where such a switch fabric will play a role. The ONF is working on implementing 5G network core functions and features such as network slicing, using the P4 language to run core tasks on intelligent fabric.
The ONF has already done work separating the radio access network (RAN) controller from radio frequency equipment and aims to use SDN to control a pool of resources and make intelligent decisions about the placement of subscribers, workloads and how the available radio spectrum can best be used.
The ONF’s fifth reference design addresses next-generation SDN and will use work that Google has developed and is contributing to the ONF.
The ONF manages the OpenFlow protocol, used to define the separation between the control and data forwarding planes. But the ONF is the first to admit that OpenFlow overlooked such issues as equipment configuration and operational issues.
The ONF is now engaged in a next-generation SDN initiative. “We are taking a step back and looking at the whole problem, to address all the pieces that didn’t get resolved in the past,” says Sloane.
Google has also contributed two interfaces that allow device management and the ONF has started its Stratum project that will develop an open-source solution for white boxes to expose these interfaces. This software residing on the white box has no control intelligence and does not make any packet-forwarding decisions. That will be done by the SDN controller that talks to the white box via these interfaces. Accordingly, the ONF is updating its ONOS controller to use these new interfaces.
From reference designs to deployment
The ONF has a clear process to transition its reference designs to solutions ready for network deployment.
The reference designs will be produced by the eight operators working with other ONF partners. “The reference design is to help others in the industry to understand where you might choose to swap in another open source piece or put in a commercial piece,” says Sloane.
This explains how the components are linked to the reference design (see diagram above). The ONF also includes the concept of the exemplar platform, the specific implementation of the reference design. “We have seen that there is tremendous value in having an open platform, something like Residential CORD,” says Sloane. “That really is what the exemplar platform is.”
The ONF says there will be one exemplar platform for each reference design but operators will be able to pick particular components for their implementations. The exemplar platform will inevitably also need to interface to a network management and orchestration platform such as the Linux Foundation’s Open Network Automation Platform (ONAP) or ETSI’s Open Source MANO (OSM).
The process of refining the reference design and honing the exemplar platform built using specific components is inevitably iterative but once completed, the operators will have a solution to test, trial and, ultimately, deploy.
The ONF says that since announcing the strategic plan a month ago, several new partners - as yet unannounced - have committed to join.
“The intention is to have the reference designs up and running before the end of the year,” says Sloane.