Making Sense of the SDN Landscape

Understanding SDN, as a concept, is relatively simple. But understanding the SDN landscape can be difficult. Here are some of the major players in the SDN standards bodies landscape and why they’re significant.

The Open Networking Foundation:

The Open Networking Foundation (ONF) is in charge of the OpenFlow standard, which defines how the control layer and delivery layer are meant to function, and the protocols for how they interact. It enables remote controllers to correctly route packets through the network, separating control from forwarding – the technological foundation of SDN. OpenFlow allows for remote administration of packet forwarding tables, and can add, modify, and remove packet matching rules and actions.
ONF is a user-led organization that promotes the adoption of SDN. A number of switch and router vendors have announced to support or are shipping supported gear for OpenFlow, including Alcatel-Lucent, Big Switch Networks, Brocade Communication, Arista Networks, Cisco, Dell Force10, Extreme Networks, IBM, Juniper Networks, Larch Networks, HP, NEC, and MikroTik.

OpenDaylight Project:

OpenDaylight is a collaborative open source project hosted by The Linux Foundation. It’s a consortium of about 20 vendors. They’re looking at the SDN architecture to try to define an open source controller, as well as defining and formalizing APIs to the application layer. In short, OpenDaylight will deliver a common open source framework and platform for SDN across the industry. This is really important because it’s one of the areas that has to mature if we’re going to see broad-based adoption by enterprises and service providers.

IETF: Internet Engineering Task Force / I2RS: Interface to the Routing System

The IETF operates a number of working groups designed to improve networking features and interconnectivity. Not all of them are SDN-based, but many of them touch on issues found primarily in SDN networks.

Much of the emphasis in SDN so far has been in switch networks, (i.e., data centers) but there has been significant improvement in router networks, due in part to the I2RS, an IETF working group.

The I2RS defines the data model for the topology of the network in OSPF and IS-IS networks. Specifically, they define what fits the definition of a “router” in an SDN, and are developing APIs that allow routers to connect to one another so that the topology can be interpreted properly, allowing network engineers to read and program the network remotely.

They also develop a data model for routing information, basically representing all the routes in the routing table. You can read it, you can see what the correct paths are, and you can also insert new routes so that you override the routes that the IGP has computed. This is extremely important for programmability in the network, a key part of the SDN concept.

The management vendors are lagging behind in all this. As our CTO Cengiz Alaettinoglu stated in an article he wrote for Wired Innovation Insights: “We need to take best practices that work in today’s manually configured networks and apply them to tomorrow’s programmable networks. This will require new management technology that can stay in sync with dynamic SDN environments.”

Cengiz is leading the development of our Network Access Broker (NAB), which will verify if the network can handle the traffic demands of SDN applications without impacting other applications adversely. The NAB will understand how the topology is changing and what commitments have been made in the network, so that when new requests come in via the SDN controller, network professionals can understand whether or not those can be met.

And… we will be showcasing automated SDN provisioning via integration of our Route Explorer System with the OpenDaylight Controller at Cisco Live in San Francisco later this month. If you are attending the event, come to the Packet Design booth to see the demo.