Being able to offer high-quality network connectivity is often a major selling point for data center facilities. This means that minimizing latency has to be a top priority for all data center managers. Here is a quick guide to what you need to know.

Understanding latency and why it matters

Latency refers to the time it takes for data to travel from its source to its destination across a network. It is typically measured in milliseconds (ms). As latency increases, the responsiveness of applications and services decreases (and vice versa).

In the business world, there is often a direct link between minimizing latency and maximizing profitability. This is because latency essentially forces employees to be idle while they are waiting for the app or service to deliver a response. While each instance of latency can have a small impact, the accumulated effect can be significant.

Latency can also lead to customer dissatisfaction. For example, many businesses now use online customer relationship management (CRM) platforms. If these experience latency, then customer service takes longer. The impact of this is exacerbated if the CRM platforms are integrated with other apps that also experience latency (e.g. VoIP services).

Common causes of latency in data centers

There are many different types of latency in data centers with many different causes. That said, there are five that stand out. Here is an overview of them.

Network congestion: Network congestion occurs when the data traffic exceeds the network’s capacity to handle it efficiently. During peak usage times, the volume of data packets being transmitted can overwhelm the network infrastructure, causing delays.

Propagation delay: Propagation delay is the time it takes for a data packet to travel from the source to the destination. This delay is influenced by the physical distance between the two points between which the data needs to travel.

Routing and switching delays: Every time a data packet passes through a router or switch, it incurs a delay due to processing time. Routers and switches must examine the packet, determine its destination, and decide the best path to forward it. These delays add up, especially if packets must traverse multiple hops to reach their destination.

Server processing time: Once a data packet reaches its destination server, additional delays can occur due to the time taken by the server to process the request. Factors contributing to server processing delays include the server’s workload, the efficiency of the server’s hardware, and the complexity of the data request. High server processing time can lead to bottlenecks, further increasing the latency experienced by users.

Protocol overhead: While essential for reliable communication, network protocols do introduce overhead in the form of additional data. For example, protocols will typically add headers and control information that ensure data integrity and correct sequencing.

Network optimization strategies to minimize latency in data centers

Just as there are different factors that lead to latency, so there are different strategies to mitigate it. Here are five of the main ones.

Traffic shaping

Traffic shaping, also known as packet shaping, is a technique used to control the flow and volume of network traffic. By regulating data transmission rates, traffic shaping ensures that critical applications receive the necessary bandwidth while preventing network congestion.

It involves setting policies that prioritize certain types of traffic, such as real-time communications or business-critical applications, over less time-sensitive data.

Caching

Caching involves storing frequently accessed data in a temporary storage location, such as a memory cache or a dedicated caching server, closer to the end-user.

This reduces the need to retrieve data from the original source each time it is requested, significantly lowering the data retrieval time.

It is possible to implement caching at various levels. These include client-side (browser cache), server-side, and distributed caching systems.

Content delivery networks (CDNs)

CDNs consist of a network of distributed servers that cache content closer to the end-users. In some cases, these servers may be at the very periphery of the network (edge computing).

When a user requests content, it is served from the nearest CDN node. This reduces the distance the data must travel and thus reduces latency.

Optimized routing protocols

Implementing advanced routing protocols such as Border Gateway Protocol (BGP) optimization or Software-Defined Networking (SDN) can enhance data packet routing efficiency. These protocols dynamically adjust routing paths based on current network conditions, such as congestion or failures, ensuring data takes the most efficient route.

Quality of service (QoS)

QoS is a set of techniques used to manage network resources and ensure the performance of specific types of traffic. By assigning different priority levels to different types of traffic, QoS ensures that high-priority applications, such as VoIP or video conferencing, receive the bandwidth they need without being affected by lower-priority traffic.