Nicira is a startup that freshly existed in stealth, but has already managed to gain an impressive customer base and quite a bit of funding thanks to its new angle on virtualization. Stanford‘s Martin Casado and Nick McKeown, together with Scott Shenker from the University of California, took virtualization to the next level by co-founding Nicira, and offering up a network-on-demand to enterprises that need  to address customer usage spikes.

The company is introducing the concept of the cloud to the networking layer. It offers an alternative to buying costly IT gear in order to handle demand overflows, and instead enables clients to offload traffic during peak-times to its own data centers. Cloud host Rackspace is one of the biggest names on Nicira’s user list today, along with carrier AT&T, eBay and others.

Wikibon analyst Stu Miniman believes that in the long run, this new tech will appeal more to cloud companies rather than enterprises, and that – while Nicira has the potential of turning out as a disrupting force in the networking world – it’s not ready to take on Cisco just yet.

“Network virtualization is the biggest change to networking in 25 years,” said Stephen Mullaney, chief executive of Nicira. “NVP provides the final pivotal piece to cloud computing, the most transformational change to IT in a generation. And the largest most forward-thinking cloud providers are laser-focused on operations and economics, the two benefits Nicira delivers.”

This pitch seems to have done its magic on some of the higher-profile VCs in the tech industry. In the same announcement, Nicira revealed its product the startup announced that it has raised $50 million from Andreessen Horowitz, Lightspeed Venture Partners, NEA and a couple of independent investors – which is none too shabby for a seed funding round.

Nicira is not the only one that has been disrupting the traditional network recently. IBM unveiled an OpenFlow-based product in collaboration with NEC a couple weeks ago.