To date, the majority of software-defined network (SDN) solutions have been focused on the data center. Recently, though, there has been an increase in the number of vendors that provide wide area network (WAN)-based SDN solutions. As is the case with the data center, the term is very broad and means everything from orchestration of services to programmability to network functions virtualization (NFV) to multi-pathing. Technically, since all of these are controlled by software, the term “software-defined networks” is accurate but the breadth of meaning does cause confusion with network managers.
I’ve had many network managers ask me what problem they should be focused on solving with an SDN. Just because SDNs can theoretically solve 101 problems, doesn’t mean any IT shop is going to try and solve all 101 all at once. Rather, a better way to get started is to think of the top 2-3 pain points and focus the SDN efforts there.
Part of my role with my media partner, Tech Target, is to develop surveys that look at the purchasing trends around network infrastructure. Recently we ran an SDN survey and instead of focusing only on data center SDNs, we did ask about WAN based SDNs.
One of the questions, “What capabilities are most important to you in an SDN/network virtualization solution for your WAN?” allowed respondents to choose their top three most important capabilities. Of the almost 200 respondents, the top choice was “automated network provisioning and bandwidth on demand” with 85% of the respondents choosing this. The second most-selected response was “Dynamically prioritize traffic types” (70%). See a point of commonality here? Both responses deal with automating management tasks associated with the WAN.
I understand why the industry has focused its efforts on the evolution of the data center. Virtualization has turned the data center upside down and network managers are left to deal with the impact. However, the WAN has undergone its own shift as cloud computing and mobility have caused the WAN to be overhauled in recent year. Also, the WAN typically has an order of magnitude or two less bandwidth than the data center. This means network managers have to constantly tweak and tune the network as things change. Making WAN changes can be difficult and risky as changes are typically done remotely since few branch offices have an actual person in it. Sure, if you’re lucky you might be able to get someone in the branch to tell you what lights are on a box or to turn a device off and then back on, but that’s the extent of remote support.
How does one make managing the WAN easier? Automate the management and provisioning tasks! If an application is using too much bandwidth and it’s killing the connection, instead of having to manually adjust the network, have an SDN solution do it automatically. This cuts down on help desk calls and improves user satisfaction. It also cuts down the human error factor, which is the single largest cause of downtime in the network today.
Interestingly, in the survey, the #3 response was “real time traffic monitoring” and #4 was “prioritize delivery of key applications”. While these aren’t directly related to automation, they are related to being able to understand what’s happening on the network and then being able to fix it. Other factors such as programming the network via APIs and even securing the network fall way down this list.
What’s this mean? Well it means the industry can talk about future things like programmability, but ultimately it appears network managers are still struggling with just getting applications to perform well over the WAN. Automation is becoming a bigger theme across IT and needs to be the key theme when it comes to WAN based SDNs.