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Network TAPs or Packet Brokers for Software-Defined Networks?

Written by Chris Bihary | 3/7/17 1:00 PM

Centralized, programmatic control of the network—this was the major promise software-defined networking (SDN) offered when it first emerged. We’re getting there, but if the last few years have shown us anything it’s that realizing lofty SDN goals is anything but easy.

Now might not be the time to implement an a prior data model with an SDN protocol like OpenFlow, but you can still lay the groundwork for SDN in 2017.

The only question is how.

If you’re looking at creating a visibility plane to achieve the centralized management of SDN, you might think of choosing between network TAPs and network packet brokers (NPBs). Why not both?

The Network TAP Base

At its core, the idea of centralized management in SDN simply means total visibility into all infrastructure and traffic without having to examine hundreds of individual links and devices. However, if you’ve recently looked into achieving this kind of SDN management, you’ve likely seen vendors arguing between network TAPs and packet brokers.

Don’t get sucked into the debate between network TAPs and NPBs—they each serve a specific purpose for SDN.

In your new SDN deployment, network TAPs will serve as the edge foundation of centralized management. You have links between routers and switches at the edge and multiple in-line security appliances chained to maintain your cybersecurity goals.

Network TAPs are critical for guaranteeing 100% visibility for these edge appliances today and it won’t change as you transition to software-defined networking. Using network TAPs to chain at the edge will be the ground level as you feed every bit, byte and packet® through to your central management solution.

Central Management with Network Packet Brokers

Once you’ve collected all traffic from in-line security appliances at the edge, you can route that traffic through a layer of network packet brokers (NPBs) to achieve centralized management.

Because NPBs can centralize network traffic from many links, network TAPs and edge appliances, you can share packets across many monitoring tools and out-of-band security appliances. But the key component that makes NPBs viable for SDN is their ability to filter, aggregate, regenerate, and load balance that traffic.

Other SDN solutions focus on bare metal switches and open protocols to automate these NPB functions, but many of these protocols are flawed and many companies aren’t ready for a wholesale shift to open networking. And if your visibility plane is compromised in any way, what’s the point of implementing SDN in the first place?

 In addition to guaranteeing the visibility necessary for centralized management, NPBs can also help you achieve the cost efficiency you expect from SDN. A recent eWeek survey found that cost efficiency is a polarizing factor when implementing SDN—it’s both the greatest benefit and the greatest challenge for the companies that have already made the shift.

Part of this challenge is that struggling companies haven’t found a way to best leverage their existing investments in routing and switching technologies. They’re just too eager to make sweeping changes. However, when you use network TAPs and NPBs together to achieve centralized management, you can make the most of existing 1G or 10G appliances even as you move to a 40G or 100G data center.

If you want to learn more about laying the groundwork for software-defined networking, download our free white paper, Architecting Data Centers for SDN and NFV.