When Public Cloud Isn’t Public

One of the key misnomers in cloud technology today is the idea of “public cloud”.  In our work with clients, and especially when discussing Infrastructure as a Service providers such as Amazon Web Services, we invariably have to walk some potential clients off the “public cloud” ledge.  Companies such as AWS are immediately labeled “public” simply because the public can access it.

In fact, we recently worked with a client that asked if AWS could meet the NIST definition of “private cloud.”  The answer is emphatically yes.  NIST defines private cloud as:

[C]loud infrastructure is provisioned for exclusive use by a single organization comprising multiple consumers (e.g., business units). It may be owned, managed, and operated by the organization, a third party, or some combination of them, and it may exist on or off premises.
– NIST Publication 800-145, The NIST Definition of Cloud Computing, at pg. 3.

It is a simple two-sentence definition, so let us look at what is there and why AWS can qualify as a private cloud.  Quite simply, the use of the AWS Virtual Private Cloud provides the exclusivity that is required for private cloud status.  Per the AWS web site, VPC:

…lets you provision a logically isolated section of the Amazon Web Services (AWS) Cloud where you can launch AWS resources in a virtual network that you define. You have complete control over your virtual networking environment, including selection of your own IP address range, creation of subnets, and configuration of route tables and network gateways.

The client, of course, does not directly own the physical AWS hardware but the logical isolation afforded by the use of VPC allows the deployed AWS infrastructure to be exclusive to the client.

The second sentence’s key component is that the term “combination”.  In the case of the Federal Government, the combination is key.  As we encourage all of our clients to do, they should own their own account, meaning the Government owns the AWS infrastructure (above the hypervisor), manages that infrastructure, and operates the infrastructure.  If it chooses, a third party provider, such as JHC, can also handle the management and operation – the “third-party” NIST identifies.

At the end of the day, cloud knowledge continues to filter down, and we are always happy to provide as much of it as we can.  I hope that we will quickly dispel the misnomer of AWS and others as public clouds simply because the public can use the infrastructure.  Once deployed correctly, AWS and others transition directly into private clouds.

Matt Jordan is the Cloud Services Manager for JHC Technology. He can be reached at mjordan(at)jhctechology.com, @matt_jhc, or connect with him on LinkedIn.