What Is Cloud Networking?

Cloud networking is the practice of hosting and managing network resources in or through the cloud rather than on physical hardware at a single site. Cloud networking places functions such as connectivity, routing, security, and management in a cloud provider’s infrastructure, where software defines and controls the network instead of dedicated on-site appliances. Providers such as Amazon Web Services (AWS), Microsoft Azure, and Google Cloud deliver these resources on demand over the internet or private links.

This article defines cloud networking, explains how it works through virtual networks and software-defined networking, sets out its benefits, lists the common services that deliver it, and compares cloud networking with on-premises networking. Each section states one part of the topic and connects it to the network resources and management hosted in the cloud at the center of the definition. The result is a complete account of what cloud networking is, how it functions, and where it differs from traditional on-site networks.

What Is Cloud Networking?

Cloud networking is the hosting and management of network resources, such as connectivity, routing, and security, in a cloud provider’s infrastructure rather than on local hardware. Cloud networking moves the control and delivery of a network into the cloud, where software configures virtual networks that run on the provider’s physical equipment. The defining traits of cloud networking are listed below:

• Hosted resources place routing, firewalls, and load balancing in the cloud instead of on-site appliances.
• Software-defined control configures the network through software rather than manual hardware setup.
• On-demand provisioning creates and removes network resources through a portal or an application programming interface.
• Internet or private delivery connects users and sites to the cloud network over the internet or dedicated links.

Cloud networking builds on the broader model of computing delivered over the internet, defined in the overview of cloud computing. The virtual networks it creates carry traffic using the addressing described in the overview of an IP address.

How Does Cloud Networking Work?

Cloud networking works by defining virtual networks in software, controlled through software-defined networking, that run on a cloud provider’s physical infrastructure. Cloud networking separates the network’s control logic from the underlying hardware, so administrators configure connectivity through software rather than by wiring devices. The mechanisms behind cloud networking are listed below:

• Virtual networks isolate each customer’s resources in a logically separate network on shared hardware.
• Software-defined networking (SDN) separates the control plane from the data plane so software directs traffic.
• Cloud-managed devices let administrators configure routers, switches, and firewalls from a central console.
• Application programming interfaces automate the creation and change of network resources through code.

A virtual network in the cloud uses the same addressing and protocol suite as a physical network, described in the overview of TCP/IP. Software-defined networking gives the cloud its central control, configuring the paths data follows across the network through software.

What Is a Virtual Private Cloud (VPC)?

A virtual private cloud (VPC) is an isolated virtual network within a cloud provider’s infrastructure, where a customer defines IP ranges, subnets, and routing for their own resources. A virtual private cloud gives one organization a private, logically separated section of the provider’s network, configured as if it were a dedicated data center. The traits of a virtual private cloud are listed below:

• Logical isolation separates each customer’s network from every other tenant on shared hardware.
• Customer-defined addressing lets the organization choose IP ranges and divide them into subnets.
• Route tables control how traffic moves between subnets and out to the internet or private links.
• Security groups filter traffic to and from resources, acting as virtual firewalls.

A virtual private cloud divides its address space into subnets using the same logic as a physical network, based on the addressing in an IP address. AWS calls this service Amazon VPC, while Microsoft Azure calls its equivalent an Azure Virtual Network (VNet).

What Are the Benefits of Cloud Networking?

Cloud networking provides scalability, central management, reduced hardware, and faster provisioning compared with networks built on dedicated on-site equipment. Cloud networking shifts capacity and control to the provider, so an organization adjusts its network without buying and installing physical devices. The benefits of cloud networking are listed below:

• Scalability adds or removes capacity on demand without purchasing new hardware.
• Central management configures sites and resources from one console rather than device by device.
• Reduced hardware lowers the count of on-site appliances an organization owns and maintains.
• Faster provisioning creates networks and changes in minutes through software and automation.

Cloud networking trades capital spending on equipment for on-demand resources billed by use, the same economic shift behind cloud computing. Central management through software replaces the manual configuration of physical devices at each site.

What Are Common Cloud Networking Services?

Common cloud networking services include Amazon VPC, Azure Virtual Network, load balancers, cloud firewalls, and SD-WAN, each delivering one network function through the cloud. A cloud networking service replaces a category of on-site equipment with a managed, software-defined equivalent. The common cloud networking services are listed below:

• Amazon VPC and Azure Virtual Network provide isolated virtual networks for a customer’s cloud resources.
• Cloud load balancers distribute incoming traffic across multiple servers to spread the workload.
• Cloud firewalls and security groups filter traffic to protect resources without physical appliances.
• Software-defined wide area networking (SD-WAN) connects branch sites over the internet under central software control.
• Direct connections, such as AWS Direct Connect and Azure ExpressRoute, link a data center to the cloud over a private link.

Software-defined wide area networking connects an organization’s branch sites through the cloud, applying the central control of how networks work across distant locations. A content delivery network is a related cloud service that caches content near users, explained in the overview of a CDN.

How Does Cloud Networking Differ From On-Premises Networking?

Cloud networking hosts network resources in a provider’s infrastructure and configures them through software, while on-premises networking runs network resources on hardware the organization owns and maintains on site. Cloud networking shifts ownership, control, and cost to a subscription model, whereas on-premises networking keeps them within the organization. The differences are listed below:

• Cloud networking hosts resources in the provider’s data centers, billed by use.
• On-premises networking runs resources on equipment the organization buys and houses.
• Cloud networking scales on demand and configures through software and automation.
• On-premises networking scales by purchasing hardware and configuring each device manually.

Cloud networking and on-premises networking often combine in a hybrid model, where an organization keeps some resources on site and connects them to cloud resources through a private link. The choice depends on cost, control, and the need to scale capacity quickly.

Is Cloud Networking Secure?

Cloud networking secures resources through network isolation, security groups, encryption, and a shared responsibility model that divides duties between the provider and the customer. Cloud networking applies the same security principles as a physical network, implemented in software, with the provider securing the infrastructure and the customer securing their configuration. The security controls in cloud networking are listed below:

• Network isolation separates each customer’s virtual network so tenants cannot reach one another’s traffic.
• Security groups and firewalls filter inbound and outbound traffic at the resource level.
• Encryption protects data in transit over private links and the internet.
• The shared responsibility model assigns infrastructure security to the provider and configuration security to the customer.

The shared responsibility model means a customer must configure security groups and access rules correctly, since the provider secures only the underlying infrastructure. Filtering traffic by port is one such control, using the network ports that identify each service.

What Are the Deployment Models of Cloud Networking?

Cloud networking is deployed in public, private, and hybrid models, which differ in who owns the infrastructure and how the network connects to it. A deployment model defines where the cloud network runs and how an organization reaches it, from fully shared infrastructure to a combination of cloud and on-site resources. The deployment models of cloud networking are listed below:

• Public cloud networking runs on a provider’s shared infrastructure, such as AWS, Azure, or Google Cloud.
• Private cloud networking dedicates infrastructure to one organization, hosted on site or by a provider.
• Hybrid cloud networking connects on-premises resources to public cloud resources over a private link.
• Multi-cloud networking links resources across more than one public cloud provider under common management.

A hybrid model connects an organization’s own equipment to public cloud resources, often through a private link such as AWS Direct Connect or Azure ExpressRoute. These models extend the broader deployment choices described in the overview of cloud computing, applied to the network layer.

Key Takeaways

• Cloud networking hosts network resources and management in a cloud provider’s infrastructure.
• It works through virtual networks, software-defined networking, and cloud-managed devices.
• A virtual private cloud (VPC) is an isolated virtual network a customer configures in the cloud.
• Benefits include scalability, central management, reduced hardware, and faster provisioning.
• Common services include Amazon VPC, Azure Virtual Network, cloud load balancers, and SD-WAN.
• Cloud networking differs from on-premises networking in location, ownership, scaling, and cost.

Last Thoughts on Cloud Networking

Cloud networking hosts and manages network resources in a cloud provider’s infrastructure rather than on local hardware, using virtual networks and software-defined networking for central control. A virtual private cloud gives each customer an isolated, configurable network, while services such as Amazon VPC, Azure Virtual Network, load balancers, and SD-WAN deliver specific functions on demand.

Cloud networking provides scalability, central management, and reduced hardware, differing from on-premises networking in location, ownership, scaling, and cost. Readers can continue with the overview of cloud computing, the guide to a CDN, the overview of TCP/IP, or the guide to how networks work.