Industry Insights

Intent-based Networking and the WAN

According to Andrew Lerner of Gartner, “Intent-based networking is not a product, or a market. Instead, it is a piece of networking software that helps to plan, design and implement/operate networks that can improve network availability and agility.”

We have seen huge inroads in the development of the algorithms and overlays used in abstracting the network control plane away from the underlying data plane. These advancements in software defined networking (SDN) will prove to be the foundation for effective intent-based networking. When you look at recent generation 2 SD-WAN technologies, you begin to see the formation of this paradigm. Being able to direct application traffic via business priority rather then through the manipulation of traffic via metrics or other static and deterministic means is the definition of intent-based networking.

Most current networks utilize routing protocols to ensure connectivity to local and remote networks. On the interior they range from EIGRP to OSPF and almost all use BGP exclusively for remote and Internet connections. Routing protocols are designed to either determine shortest path to the destination network or using distance vector calculations with the common characteristic that all of the underlying data is network-centric. They ensure the ability to recover from physical issues on the network by re-routing via redundant paths.

In an article written for Forbes by Will Townsend of Moor Insights and Strategy, SDN is a collection of network objects such as routers, switches, and firewalls that are deployed and managed in an automated manner. It is when you marry intelligence with SDN that you arrive at the definition of intent-based networking.

So far we have seen, in the market, a good direction of LAN, Data Center, and WAN technologies that are rapidly evolving from simple SDN solutions towards true intent-based. However, none of these solutions, except the generation 2 SD-WAN products, have demonstrated the intelligence required for ensuring correct application delivery from end to end with all business drivers being considered.  Unlike general networking technologies, generation 2 SD-WAN understands data points from both the underlying network and the application itself.

I would like to postulate a new definition that builds upon those described by Mr. Lerner, and Mr. Townsend. Intent-based networking is a solution that allows for rapid and automatic provisioning of required systems with the capabilities of machine learning to constantly evolve the network based upon learning the characteristics and performance of applications and any deviations from the desired state and business policy.

A crucial piece of the intent-based landscape will the interoperability of these individual solutions that encompass the LAN, Data Center, and WAN. A common policy controller that deals with the sum of the network including from the LAN access switches, or home user through the internet ultimately across the WAN and Data Center networks to the end host. The most crucial pieces being the WAN and last mile.

Over the next 12 to 18 months we should begin to see some convergence on these fronts. Additional saturation of broadband and competition will also play a role. Having divergent communication from multiple broadband providers, including 4G and 5G will create a solution that’s been used in storage technology for the past decade. Only instead of JBOD (Just a Bunch of Disks), we will see the proliferation of JBOL (Just a Bunch of Links). We won’t care where the bandwidth comes from, or how it is routed, just that we have an adequate supply that maintains the characteristics necessary to meet our business intent.

So, where will this take us?  Routing technology has reached its limits in terms of ability to deliver the agility and adaptability that business requires. The addition of overlays on top of our existing Layer 3 topologies will allow for faster convergence, and dynamic path selection based upon more than just the latency, loss, and jitter measurements we have today is fundamental to ensuring business intent is met. When you look at product suites like Office 365, you might notice that email will function fine with some fluctuations in latency and some loss, but your Skype sessions won’t. The policy controller will be able to route the different types of traffic based upon application needs and the way the application performs over certain classes of links. It will send email via standard Internet, SQL traffic via your direct connect MPLS, and the voice via a 4G connection. All the traffic is destined for the same network, but the paths offer different performance and availability characteristics, and they will be selected based on how they best match the needs of the application in their current state.

Intent-based networking is the only path forward to next generation services that the customers will require.

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