Category: OpenFlow

David Le Goff sent me several great SDN-related questions. Here’s the first one:

What is your take on the performance issue with software-based equipment when dealing with general purpose CPU only? Do you see this challenge as a hard stop to SDN business?

Short answer (as always) is it depends. However, I think most people approach this issue the wrong way.

This post is probably a bit premature, but I’m positive your CIO will get a visit from a vendor offering clean-slate OpenFlow/SDN-based data center fabrics in not so distant future. At that moment, one of the first questions you should ask is “how well does your new wonderland integrate with my existing network?” or more specifically “which L2 and L3 protocols do you support?”

Every time I write about a simple use case that could benefit from OpenFlow, I invariably get a comment along the lines of “you can do that with NETCONF”. Repeated often enough, such comments might make an outside observer believe you don’t need OpenFlow for Software Defined Networking (SDN), which is simply not true. Here are at least three fundamental reasons why that’s the case.

A few days after Brocade unveiled its SDN/OpenFlow strategy, Katie Bromley organized a phone call with Keith Stewart who kindly explained to me some of the background behind their current OpenFlow support. Apart from the fact that it runs on the 100GE adapters, the most interesting part is their twist on the hybrid OpenFlow deployment.

As expected, Cisco launched its programmable networks strategy (Cisco Open Networking Environment – ONE) at Cisco Live US ... and as we all hoped, it was more than just OpenFlow support on Nexus 3000. It was also totally different from the usual we support OpenFlow on our gear me-too announcements we’ve seen in the last few months.

A few days ago Big Switch announced they’ll support overlay networks in their upcoming software release. After a brief “told you so” moment (because virtual networks in physical devices don’t scale all that well) I started wondering whether they simply gave up and decided to become a Nicira copycat, so I was more than keen to have a brief chat with Kyle Forster (graciously offered by Isabelle Guis).

Last autumn Todd Hoff (the author of the fantastic High Scalability blog) asked me to write a short article explaining the scalability challenges SDN and OpenFlow in particular might be facing. It took me “a while”, but I finally got it done – the OpenFlow/SDN Is Not a Silver Bullet for Network Scalability article was published last Monday.

We knew Brocade has OpenFlow support in its devices for at least a year; now it’s official: OpenFlow is supported on its MLX-series routers. But wait, there’s more: that’s just the first step in Brocade’s long-term SDN strategy, according to their press release. Let’s take a deeper look at that strategy.

Google unveiled some details of its new internal network at Open Networking Summit in April and predictably the industry press and OpenFlow pundits exploded with the “this is the end of the networking as we know it” glee. Unfortunately I haven’t seen a single serious technical analysis of what it is they’re actually doing and how different their new network is from what we have today.

The blogosphere has been full of OpenFlow-related articles recently (no wonder - there was Open Networking Summit in Santa Clara), so here's a special OpenFlow edition of interesting links

Let's start with my good friend Greg Ferro. I'm so glad to see him returning back from a sabbatical at OpenFlow Kool-Aid lake. His latest articles are a must-read: OpenFlow might lower CapEx while SDN will increase OpEx and OpenFlow doesn’t undermine Vendors even though it changes everything. We're perfectly aligned, which will make our discussions way less interesting, but I'm glad I'm not the only conservative in the town.

Matt Stone sent me a great set of questions about the emerging Data Center technologies (the headline is also his, not mine) together with an interesting observation “it seems as though there is a lot of reinventing the wheel going on”. Sure is – read Doug Gourlay’s OpenFlow article for a skeptical insider view. Here's a lovely tidbit:

So every few years the networking industry invents some new term whose primary purpose is to galvanize the thinking of IT purchasers, give them a new rallying cry to generate budget, hopefully drive some refresh of the installed base so us vendor folks can make our quarter bookings targets.

But I’m digressing, let’s focus on Matt’s questions. Here are the first few.

HP has recently released OpenFlow support on a few more switches and some people think it’s a big deal. It just might be if you’re a researcher with limited grant budget (which seems to be one of the major OpenFlow use cases today); for everyone else, it’s a meh. Lacking a commercial-grade OpenFlow controller supported by HP (or at least tested with HP switches), OpenFlow on HP switches remains a shiny new toy.

When I was writing about the NEC+IBM OpenFlow trials, I figured out a perfect use case for OpenFlow-controlled network forwarding: SMB data centers that need less than a few hundred physical servers – be it bare-metal servers or hypervisor hosts (hat tip to Brad Hedlund for nudging me in the right direction a while ago)

A reader of my blog sent me this question:

I am a Telecommunication Engineer currently preparing for the CCIE exam. Do you think that in a near future it will be worth to be a CCIE, due to the recent developments like Nicira? What will be the future of Cisco IOS, and protocols like OSPF or BGP? I am totally disoriented about my career.

Well, although I wholeheartedly agree with recent post from Derick Winkworth, the sky is not falling (yet):

After all the laws-of-physics-are-changing hype it must have been anticlimactic for a lot of people to realize what Nicira is doing (although I’ve been telling you that for months). Not surprisingly, there were the usual complaints and twitterbursts: