5. The number of virtual machines within an organization's network
"If you're not at a few hundred, you're probably early," Castelino says. He reiterates that if an organization is running hundreds of workloads, it might be worth taking a look at SDNs. Below that level, and with SDN's immaturity, it might be "way too early" to look at.
6. The organization's need for agility, flexibility and scalability within the network
See Nos. 4 and 1: If you have a business or IT environment that scales quickly and changes dynamically, you want SDN. But the eventual ease of operations will come with some initial work. The time it takes to get into SDN is not small today, Castelino notes -- it's still at the bleeding edge of the technology curve.
"Network engineering skills and capital resources are going to be key," he says. "It could be an expensive proposition so you need to ensure value on the other side."
7. The organization's need to simplify security measures and control access to applications
The benefit of SDN is that things get done the same way all the time, through policy, even though the environment is dynamic and always changing. Security and network access control in a dynamic environment can be a nightmare. It's important to get policy enforcement right in this regard not only to ease operation but to ensure information stays where it should.
8. The organization's access to personnel and capital resources
If an IT shop doesn't have network engineering expertise, or personnel is stretched thin, SDN is not the project to undertake, Castelino says.
"There will be lots of bumps in the road," he says. "It's going to be a lot of work and take time."
SDN deployments are done in parallel with the production environment, test, evaluated, validated and tested again before they are cut over to the production network. It takes time, people and money.
In summary, SDN holds a lot of promise. There are a lot of problems it can solve... but also a lot it can start if the environment is not conducive to the effort and undertaking to transition to an SDN-programmable and automated IT operation.
"The hype cycle can sometimes lead to an ugly bursting of the bubble," Castelino says. "SDN has its purpose. But if it is marketed as a panacea for everything under the sun, you'll see a lot of dramatic failures. It's not ready for everyone but some can get a lot of value out of it. You just need to go in with eyes open."
Read more about LAN and WAM in Network World's LAN & WAN section.