When it comes to the cloud, designing a network that supports all necessary applications, data and services can be a unique challenge that makes some architects wary. Because the business often doesn't own the underlying cloud components, options can feel limited. Yet, cloud networking technologies have advanced to the point where multiple choices now offer varying levels of network design depending on your needs.
In this introduction to cloud networking, we'll first define what a cloud network is. We'll then go on to discuss the three primary architecture options currently available. Lastly, we'll talk about how to select the cloud network architecture that best fits your business both today and in the future.
What is a cloud network?
The concept of cloud networks largely focuses on the ability for a cloud customer to design, configure and manage the underlying network in a private or public cloud. With a private cloud, architects have far more flexibility when it comes to the overall design because the cloud provider fully manages the underlying hardware and software on which the cloud is built.
For public clouds, customers can control and manage networking only in IaaS deployments. With SaaS and PaaS, the customer has no control over network functions as they're fully managed by the service provider. Thus, if you need to be able to configure aspects of your network in a public cloud, IaaS is your only option.
From a cloud customer perspective, many organizations opt to operate in a hybrid cloud architecture. That means some applications, data and services reside in corporate-owned and managed data centers, while others are moved to an IaaS provider infrastructure. For customers with this hybrid model, the ideal scenario would be to mimic the network IP space, policies and procedures they've already established in their own data centers. Replicating these same processes and settings into the cloud environment creates a much more uniform end-user and administration experience.
Some businesses are going an additional step further by using multiple cloud service providers (CSPs) in a multi-cloud architecture. Again, symmetry among clouds is key here from both an operational and cloud management perspective. For those companies moving toward multi-cloud, they must be able to manage routing, access lists, load balancing and other network functions, no matter which cloud they're in.
What cloud networking architecture options are available?
Businesses can evaluate three different cloud network architecture deployment methods, which are outlined below.
Built-in networking tools. The first method is to simply use the CSP's built-in networking tools provided as part of the base IaaS service. For example, if you're using the Amazon Virtual Private Cloud service, you get control over the basics, such as assigning private IP addresses of your choice, carving out the virtual network into various subnets, and creating and applying the security policies to each subnet. You also have control over the route table, internet gateways and supplemental network services, such as Dynamic Host Configuration Protocol and DNS. That said, using the built-in networking tools means you'll have to configure and manage the IaaS cloud independently of any other private or public cloud.
Virtual networking appliances. A second method is to use virtual networking appliances from a networking vendor to handle networking tasks, instead of the built-in tools offered by the cloud provider. Companies such as Cisco, Arista, Juniper and SonicWall offer several versions of their virtualized routers, firewalls and software-defined WAN appliances for sale on popular IaaS marketplaces.
Companies looking at a hybrid cloud may want to see if they can implement one or more third-party virtual appliances into the IaaS to more closely mimic network configurations already created in their private data centers. Doing so will greatly simplify initial configuration and ongoing management and maintenance.
Multi-cloud management platform. Finally, while businesses looking to build out a multi-cloud environment could try to use third-party network appliances in multiple CSPs, another option to simplify the management of multiple clouds from a configuration and policy perspective is to use a multi-cloud management platform.
These multi-cloud management tools are purpose-built to create a software overlay between private and public clouds, which masks any underlying differences in configuration management. While this option is far more complex than the other two options, it's an interesting alternative for those seeking to distribute a large network across many public cloud providers.
How do you choose a cloud network architecture?
Your ultimate choice of a cloud network architecture largely depends on short- and long-term needs. Companies currently seeking a hybrid architecture with a single primary provider may choose the built-in tools or third-party virtual network options. For those with highly distributed multi-cloud ambitions, a multi-cloud management platform may be more appropriate.
Another thing to consider is whether IaaS will truly be your organization's long-term strategy or if SaaS will be the eventual goal. According to a recent Gartner cloud service forecast, SaaS growth is expected to outpace both IaaS and PaaS. If that's the case, businesses may start rethinking their grand multi-cloud architecture ambitions in favor of a SaaS provider that requires no cloud networking at all.