CORD Connecting as ONOS Expands
Mobile CORD and Enterprise CORD
CORD uses the same SDN approach developed for data centers but adapts it for the CO environment, where there can be tens of thousands of connections, some residential, some mobile backhaul and some enterprise, Parulkar notes.
To generalize the CORD architecture developed for residential FTTH, ONOS has added access racks specific to mobile and enterprise services. For the mobile CORD, it is using Cavium Inc. (Nasdaq: CAVM)'s baseband unit, and will support disaggregated and virtualized Evolved Packet Core (EPC) and Radio Access Networks (RANs), he said.
Many operators are looking to virtualized RAN and EPC, especially as they look to scale their networks to support the Internet of Things and 5G mobile.
At this point, Enterprise CORD uses standard Metro Ethernet hardware, as merchant silicon is not yet available, though it is in development, Parulkar notes. Enterprise CORD will enable programmable wide area networks managed by SDN technology, plus other features as well. The idea is to bring to the WAN the kind of virtualization SDN brought to local area networks and give enterprises the ability to turn up their own services in an on-demand way.
"That will make enterprises happy and let service providers hang onto their enterprise customers," Parulkar says.
Everything as a service
CORD uses the ONOS SDN control plane, but ONOS also has developed its own NFV orchestration, which it calls XOS, which stands for Everything-as-a-Service operating system.
XOS creates a layer of abstraction that greatly simplifies the management of the virtual machines and containers on which virtualized network functions run, Parulkar says. Given that the number of virtual machines (VMs) or containers needed to support VNFs will be in the thousands, it is increasingly impossible to manage at that level of granularity, he notes.
"We have introduced the concept of a service, which is a higher level of abstraction, and below that abstraction we hide all of that complexity relating to managing VMs or containers or scaling up a service" he says.
In ONOS's view, XOS is where policies related to resources, scaling and customers reside.
In this approach, the virtualized optical line terminals, subscriber gateways, content delivery network elements and routers used to create Residential CORD are each considered a service and within that there may be one VM or tens of VMs, he explains. The controller for each service keeps track of all of the management needed, as well as any scaling that is required. Infrastructures such as Docker Inc. and OpenStack also fit into the same architecture and become a service that is managed by XOS.
So while ONOS is managing all the networking and network control apps, and OpenStack and Docker are being used for virtualization, XOS "sits on top and supports the paradigm of VNF-as-a-service, and then interfaces to the OSS and BSS," Parulkar explains.
Back on the ONOS side, Snow points to 50-plus members, deployments on five continents and a growing base of contributions to the open source project. ON.Lab's contribution percentage is down to 44% and continues to shrink, he notes. The next largest contributor is Huawei Technologies Co. Ltd. .
— Carol Wilson, Editor-at-Large, Light Reading