The growth of public cloud services boosts enterprise network traffic

Public cloud has become popular because it offers organizations flexibility, lower costs, and more rapid deployment. One ripple effect from its growth is a significant change in corporate network traffic patterns. Typically, most traffic, traveled East-West, inside the data center, but cloud alters that equation so more data moves North-South from inside to outside. As they embrace these services, corporations often need to upgrade their networks to ensure adequate response time.

Vendors, like Amazon Web Service, Microsoft, and Google Inc., are locked in an intense battle to emerge as the top public cloud provider. In response, they have been expanding their services and lowering pricing with the goal of attracting more customers.

Their plans have been very successful. Worldwide spending on public cloud services and infrastructure is expected to grow from $229 billion in 2019 to nearly $500 billion in 2023, a Compound Annual Growth Rate (CAGR) of 22.3%, according to market research firm International Data Corp.

A Lack of Focus

When examining these services, businesses often focus on the impact on their applications and data center staffing. With public cloud, organizations deliver software updates more quickly. In many cases, businesses also reduce their data center operations staff needs. While the business drivers are compelling, one area that is often overlooked is public cloud’s impact on the enterprise network, which is quite dramatic.

The perception that public cloud makes computing infrastructure invisible is a misconception. Whether organizations themselves deal with the computer infrastructure or someone else takes on the task, a corporate network still exists, and its performance impacts how users complete their work. In fact, networks are becoming business cornerstones. Increasingly, firms need to ensure that certain performance levels meet not only internal but also external governance requirements.

So, it is vital to recognize how public cloud changes network traffic patterns. In many cases, the current network bandwidth cannot adequately support an organization’s new needs. Changes in traffic patterns are not incremental; in many cases, they are exponential. Problems arise from a move to the public cloud if a business does not pay enough attention to the network infrastructure. Consequently, IT professionals need to plan accordingly.

Data Center Design Changes

What is happening? Data center design and enterprise network traffic remained largely static for years, so corporations have had set traffic patterns. Virtualization enabled companies to place large workloads on central servers. One ripple effect was server consolidation. Previously, corporations had to add a server every time a new application was deployed, resulting in data center sprawl: tens, hundreds and even thousands of servers strewn across large data center. These systems were expensive, complex, and hard to maintain. With virtualization, corporations ran more workloads on their servers and dramatically consolidate their hardware systems.

Hyperconverged hardware advanced that trend further. Here, vendors collapsed autonomous server, storage, virtualization, and network functions running on multiple devices into one box.

The end result of these changes was high growth in East-West traffic, for example, a server writing data to a storage system. In this case, little traffic moves out of the data center and onto the enterprise network as functions travel only short distances, maybe a few hundred feet. In many cases, as much as 70% of the traffic is in the data center and 30% funneled onto the network.

The advent of public cloud disrupts these patterns. Traffic no longer remains constrained and instead flows into and out of the data-center. Information entering the data center through the perimeter network is said to be southbound. Traffic exiting via the perimeter is northbound. With public cloud, traffic moves from a business’ data center out to the provider’s data center and back again. So, the traditional traffic mix is flipped.

Where the Rubber Meets the Road

A number of potential ripple effects follow. This change in architectural design may inadvertently trigger more congestion, network overloads, and poor response times. As a result, embracing the public cloud sounds appealing from the perspective of managing the components but sometimes creates unexpected performance and availability issues  Often, a business finds that a network upgrade is needed when it moves applications to the public cloud.

Public cloud deployments are growing because this approach offers organizations appealing features. When evaluating these services, businesses sometimes fail to understand their full impact and ignore how the corporate network changes. The dramatic shift in traffic from East-West to North-South can significantly diminish response times unless a business accounts for that potential problem when beginning rather than finishing its public cloud deployment.

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