INSIGHT: Delving deeper into network outages and SDN

"I’ll cut to the chase, SDN will not end all network outages."

There has been a lot in the press this week about network outages at NYSE, United Airlines and the WSJ.

Some of the articles and analysis have been good, but too many have been well, not so much.

Some of the articles touched on a) what could’ve caused the outage(s) and b) how SDN could’ve prevented them. So my thoughts…

What could’ve caused the downtime

It isn’t really a great idea to pontificate here. United says it was a router problem. That could mean everything or nothing.

I’ve run large corporate enterprise networks for over a decade and can tell you that most business-impacting outages at large and mature organisations are the result of multiple simultaneous and/or cascading issues - often a combination of technology, people and process.

Most likely that is the case for the recent outages, but I have no specific insight. That said, I’m nearly certain these networks were architected (and tested) for network resiliency. Likely a multitude of issues.

SDN could’ve fixed this…wait, what?

I’ll cut to the chase:

• SDN will not end all network outages.

• SDN is an architectural approach to networking. It has a lot of great and unique benefits compared to traditional approaches, including improved agility, management, reduced expenditure and the potential for market innovation.

• SDN also has drawbacks, and is not a panacea to fix all evils in networking. Furthermore, for those pontificating that manual changes caused the problem, lets not forget that SDN is way more than just automation and agility.

• Sure, SDN results in less manual changes, but you can get automation without SDN, and I would assume United/WSJ/NYSE was using automation (it is very difficult to operate any network at scale without it).

• Furthermore, as you move towards SDN, you’re ultimately running two architectures in the environment (since there’s very little greenfield).

Thus, during the transition, you actually have more stuff to contend with, which can make networks more complex.

Side Note: “SDN fixes everything” is now in the running for the next iteration of common SDN misconceptions (along with SDN = Open).

By Andrew Lerner - Research Analyst, Gartner