The deal between Arista and VMware may turn out to be one of the pivotal developments in SDN, and one of the pivotal steps in the evolution of networking. Just how far it will take us is, at this point, not clear because there’s the usual mixture of issues, both tactical and strategic to consider. And, as my use of the word “may” in the first sentence shows, it’s still possible this will be a flash in the pan.
Everything that’s happening in enterprise networking and a lot of what’s happening in service provider networking is linked to data center evolution. A big part of that is the notion of multi-tenancy, but for the enterprise the most important driver is the continued use of virtual resources to leverage gains in physical server power and increased componentization of software. The point is that for a decade now, everything important in enterprise networking has been driven from the data center, and that means the data center is a point of focus for vendor power struggles.
IBM has been the historical giant in data center evolution, but for the whole of the time that the data center has been getting more important, IBM has been losing strategic influence. This can be attributed to an early withdrawal from networking (which took IBM out of the main event in connectivity), lagging virtualization and cloud positioning (IBM has struggled to be a “fast follower” there) and most recently a proposed withdrawal from x86 servers. IBM’s loss here put the critical data center space more up-for-grabs than would have been the case normally.
Cisco and VMware have been the two trying hardest to do the grabbing, with HP a close third. My surveys of enterprises has showed that it’s these three companies who are driving the bus in terms of both tactical and strategic evolution of the data center. Of the three, obviously, only Cisco really takes things from a pure network perspective, and interestingly Cisco has been the one gaining strategic influence the most. Cisco can be said to have established a physical ecosystem strategy for the data center, countering the logical ecosystem strategy espoused by VMware. The conflict between these approaches is at the heart of the Cisco/VMware falling out.
The challenge for VMware, though, is that virtual/logical networking won’t move real packets. You have to be able to actually connect stuff using copper and fiber, and even the early Nicira white papers always made it clear that there was a real switching network underneath the virtual software-based SDN they promoted. VMware was leaving Cisco’s camel’s nose free to enter the tent, and I think that’s where Arista comes in. Arista is both a physical network buffer against Cisco’s so-far success in the data center, and the representative of a position that Cisco doesn’t want to take—that networks are dependent on software even when they’re physical networks.
What all this means is that VMware and Arista will surely become the most significant challenge to Cisco’s continued gains in strategic influence. If we see Cisco’s numbers fall short this week, it will likely be in part because Cisco has been unable to push a pure-hardware vision for the data center against even the limited VMware/Arista partnership we’ve had up to now. Expect a full-court press from the pair in coming quarters.
The strategic question here relates to another of my blog points last week. The best approach for SDN is likely to be a hybrid of physical and logical networking, an overlay network constructed on a more malleable model of physical networking. The Street thinks that one of the goals of the expanded relationship between VMware and Arista is to create this explicit hybridization. That’s bad for Cisco because it would validate the software vision of Arista and the hybrid model of SDN that has (IMHO) always been the greatest threat to incumbents.
What VMware/Arista could do is take advantage of the fact that building cloud or virtual data centers tends to build application networks. In an enterprise, an application is kind of like a cloud tenant in that applications are deployed separately, often through their own ALM/DevOps processes. Because at the core the networks are application-specific, the network has the potential of gaining specific knowledge of application network policies without any additional steps. You can figure out what an application’s traffic is by using DPI to pull it from a vast formless flow, but if you’ve already deployed that application using specific tools on what could easily be application-specific subnets, you already know all that you need to know.
The partnership between application deployment and virtual networking, and the extension of that partnership down into the physical layer, is what’s important here. Because VMware has a handle on application deployment in a way Cisco does not, the alliance forces Cisco to think more aggressively about its ACI positioning. It also means that we could see other vendors who recognize that logical/physical network hybrids are likely the focus of the biggest marketing contest in the industry, to take their own shot at the space.
All of this is happening as the ONF is trying to push for accelerated deployment of SDN, and they may get their wish in that sense. However, there aren’t standards in place to create what the Arista/VMware hybrid can produce. Accelerating “SDN” in the broad sense may well change the focus of SDN to higher-layer functionality and away from diddling with device forwarding one entry at a time. That would be good for the industry if the change of focus can be accommodated quickly, but it would be bad if what happens is an ad hoc logical/physical dynamic created by competition. That would almost certainly reduce the chances the next generation of network devices would be truly interoperable, at least in the systemic sense.
That’s the biggest point here. What Arista/VMware may do is to create a whole new notion of what a network is, a notion that goes deeper into applications, software, deployment than all previous notions. That new notion could change the competitive landscape utterly, because it changes what everyone is competing for.