What Is Network Congestion?

Network congestion refers to the reduced quality of service that occurs due to overloaded network nodes or links.

What Is Network Congestion?

  • Network congestion when network nodes and links are overloaded with traffic. This problem usually makes the end users’ network slow. Congestion is often related to latency, throughput, and bandwidth. IT teams need to have a proper strategy to avoid, reduce, or temporarily eliminate network congestion.

  • There are five ways to identify network congestion:

    • Bandwidth: The most common cause of network congestion is bandwidth. Bandwidth refers to the ideal capacity of the network to transfer a certain amount of data from a source to a destination in a specific amount of time. A lack of bandwidth can lead to network outages.
    • Latency: Latency is the time taken to transmit, capture, transmit, and process data from source to destination. It refers to the speed of your network traffic measured in milliseconds. High latency can lead to a slower network. Latency numbers may vary based on the application and network connection usage.
    • Jitter: Jitter refers to the time delay while sending data packets to a destination from a source over a network. When traffic becomes unpredictable, it causes jitter and network congestion. Jitter can also impact the quality of audio and video quality on your network. Network equipment and devices try to adjust the changes caused by traffic patterns, which creates jitter and leads to congestion as a cascading effect.
    • Packet retransmission: Packet retransmission is required when the movement of data packets stops due to packet loss, packet damage, or more. In such cases, data packets are resent from source to destination, increasing network congestion.
    • Collisions: Packet collision occurs when two or more network nodes try to send data simultaneously. This leads to packet loss and requires resending of packets, which can negatively impact network performance. Collision is a back-off process where all the packets have to wait to clear the network congestion. It can be due to an inappropriate connection, poor cabling, and more.
  • The first step to troubleshoot network issues such as congestion is to understand and identify their root cause. There can be several causes of network congestion:

    • Unneeded traffic: The most common cause of network congestion is unneeded traffic. It may include streaming video content, advertisements, or junk VoIP phone calls that consume bandwidth. It’s important to identify unneeded traffic before it slows down your network.
    • Misconfigured traffic: Business traffic typically comes from multiple sources.
      • Unicast traffic to support video functions, voice calls, or data transfer
      • Broadcast traffic for network operations
      • Multicast traffic for real-time media streams
      All these can be business-critical traffic; however, you need to prioritize them to eliminate network congestion. Network devices treat this intermixed traffic equally, which can cause network issues and outages. Organizations can use Quality of Service (QoS) protocols to manage misconfigured traffic.
    • Business-critical traffic: In a business network, the network manager decides which type of network is business-critical to ensure the required bandwidth is reserved. The remaining bandwidth can be used for traffic coming from other sources.
    • Outdated or non-compatible hardware: Enterprises must look for outdated and non-compatible devices and try upgrading network capacity to speed up the enterprise's network demands. A hardware upgrade is critical to have an optimal layout. If hardware assets such as switches, routers, servers, cable connections can’t handle the data speeds the network requires, they can slow down the network and lead to network congestion.
    • Overused and too many devices: Overused devices can also contribute to network congestion. Pushing devices to their maximum capacity can often result in over-utilization. Excessive volumes of device usage can also cause network congestion as they can provide a surplus of requests for data.
    • Bandwidth hogs: A bandwidth hog is the over-usage of data on a particular device. The difference between average data usage and a hog's usage depends on the user or device. It’s important to monitor bandwidth in real-time to detect a bandwidth hog.

    • Traffic and bandwidth monitoring: The first step to resolve network congestion is to identify issues such as over-utilization of devices, insufficient bandwidth, and more. Monitoring networks also provide sufficient insights to identify problematic areas. You can also use network performance monitoring tools to identify such issues quickly. Once you get insights into your network performance and how data traffic flows, you can upgrade your devices, bandwidth, or network hardware to maximize the benefit.

    • Segmenting and prioritizing: Segmenting your network into small subnets increases efficiency by letting you prioritize traffic. This also helps you accurately monitor network traffic. Segmenting networks can reduce data traffic, producing a more viable network. Prioritization refers to the capacity to minimize traffic. Critical network traffic areas need more attention than others.
  • Several network performance monitoring tools can detect bandwidth hogs and monitor network traffic to help ensure there is no congestion. These tools help to:

    • Monitor and analyze network traffic patterns down to the interface level and help IT teams identify endpoints, protocols, and applications that consume more bandwidth.
    • Create reports to analyze and monitor network bandwidth more precisely. These tools convert raw numbers into easy-to-interpret charts, tables, and utilization reports to better understand how the network is being used.
    • Get instant alerts, so you can quickly act if traffic increases or decreases and efficiently remediate the problem.
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