Understanding Network Congestion: Causes and Fixes
Has your screen ever frozen during an important video conference? Alternatively, perhaps you're experiencing a long download time when attempting to download a large file. These annoying times are frequently caused by network congestion.
We're delving deeply into the field of congestion control in this article. We'll look at how network congestion prevents the Internet from overloading with our endless data requests, how various protocols like TCP and UDP manage it, and why it matters in the era of real-time gaming, streaming, and video conferences. You will find information on the following topics related to network congestion:
- What is network congestion?
- Why is congestion control important in networking?
- What are the main causes of network congestion?
- Can cyberattacks cause network congestion?
- How do you identify network congestion?
- What is jitter in networking?
- What are consequences of network core congestion?
- How do you fix network congestion and throttling?
- How do you test network congestion?
- Quality of Service (QoS)
- Which tools for monitoring and preventing network congestion can be used?
What is Network Congestion?
Network congestion is the decrease in quality of service (QOS) that results in annoying issues that impact performance, such as high levels of jitter, packet loss, delay, or the blocking of new connections. When a network is overwhelmed with more data packet traffic than it can handle, network congestion happens. Typically, congestion in a network is a temporary problem resulting from a sudden increase in traffic. When too many demands for data and communications are made simultaneously via a network with insufficient capacity, the result is a backlog of data flow. However, in some instances, a network experiences persistent congestion, which suggests an underlying issue. A crowded network may indicate a more serious problem with your system. IT teams must have a well-defined plan to prevent, minimize, or temporarily alleviate network congestion.
As a result, it's critical to have tools for proactively detecting network congestion, both within and outside of your own network, in place for network performance monitoring.
Why is Congestion Control Important in Networking?
Congestion Control is a method that regulates the flow of data packets into the network, allowing for more efficient use of a shared network infrastructure and preventing network congestion from reaching a critical state.
The figure below illustrates our preferred example for describing how to reduce internet congestion: water being pumped through a conduit.
Figure 1. Network Congestion Illustration
The end user will take far longer to fill their bath if the water flow isn't powerful enough. However, an excessive amount of water might strain the pipe and result in leaks. Similarly, the end user may not receive enough data to have a satisfactory quality of experience (QoE) if data is not pumped through the network quickly enough. For instance, a lot of data must be coming in to provide a crisp and clear image when viewing a movie in high definition.
The pipe may not be able to manage the volume if too much data is poured into it. It can result in packet loss or data leakage, which would irritate the user by repeatedly rebuffering the video. Thus, low QoE might result from transmitting data too quickly.
Although network congestion is often temporary, it may lead to troublesome network issues that can impact performance, including elevated levels of jitter, packet loss, and latency, as well as a reduction in throughput. An overcrowded network may indicate a more significant problem within your network infrastructure.
Congestion control must balance transmitting just the right amount of data with sending too much.
What are the Main Causes of Network Congestion?
Similar to traffic during peak hours, network catastrophes can occur. Accidents may swiftly cause network congestion, whether it's due to a malfunctioning connection, a router that isn't configured correctly, or a rogue device using up all the bandwidth. This section will discuss some of the frequent accidents that might lead to traffic jams and provide advice on how to prevent them.
What, then is the root cause of network congestion? Well, there are several reasons why that could occur. These are a few of the most typical reasons of network congestion:
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Heavy Traffic Volume: Network congestion results from high traffic volumes since networks have a certain amount of bandwidth available for data transmission. Congestion arises when data transmission across the network exceeds the available bandwidth capacity.
Imagine it as a roadway in the morning or afternoon. Traffic will slow down and eventually stop if there are too many cars on the road and not enough lanes to fit them all. In a similar vein, a network will slow down and become congested if there is an excessive amount of data attempting to pass through it and not enough capacity to manage it.
Numerous causes, including the growing popularity of data-intensive applications like file sharing, video streaming, and cloud-based services, can contribute to high traffic volumes. Congestion is more likely when more devices join a network and use its bandwidth.
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Antiquated Hardware: First of all, the greater speeds and bandwidths needed to serve new apps and services could be beyond the capabilities of older technology. This may lead to an obsolescent hardware bottleneck in the network, slowing down data flow and creating congestion.
Second, out-of-date technology does not have the capabilities required to efficiently prioritize and control network traffic. It might not support Quality of Service (QoS) rules, for instance, which let network managers give important traffic types priority over less important traffic kinds. When lower-priority traffic uses up bandwidth, it can result in congestion, which can cause delays and poor network performance for important applications like VoIP quality of service.
Thirdly, network congestion may be exacerbated by obsolete hardware, which may be more prone to mistakes and malfunctions. For instance, out-of-date firmware on a switch or router increases the likelihood of packet drops and other issues, which can lead to congestion by making devices retransmit lost data.
Lastly, antiquated devices do not have the security capabilities required to fend against online attacks. In certain instances, this may result in network congestion brought on by Denial of Service (DoS) assaults, which overwhelm antiquated technology by flooding the network with data.
All things considered, antiquated hardware may play a big role in network congestion. For this reason, it's critical to periodically assess and update network devices to make sure they can support the needs of contemporary services and applications.
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Insufficient Bandwidth: One of the most frequent reasons for network overload or congestion is inadequate bandwidth. Insufficient bandwidth indicates that the network's available capacity is insufficient to fulfill the demands of the devices and applications utilizing it.
Numerous variables, such as the number of connected devices, the kinds of apps being used, and the volume of data being carried, can affect how much bandwidth is needed for a given network. Congestion may arise if the demand for bandwidth outpaces the available capacity. For instance, downloading big files or streaming high-definition video by numerous users at once might quickly eat up all of the available bandwidth and lead to congestion. Packet loss, higher latency, and sluggish network performance are the outcomes.
Congestion in the network's upstream or downstream directions can result from inadequate bandwidth. For instance, a company may not be able to download or upload data fast enough to satisfy consumer requests if it has a poor internet connection. This may result in network congestion, which would slow down traffic and cause delays.
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Network Congestion: Network congestion may be mostly caused by problems with network setup. The settings and parameters that specify how devices and applications connect with one another via a network are referred to as network configuration.
Incorrect configuration of network equipment can result in a number of issues, including congestion. For instance, a router may not be able to forward packets rapidly enough, resulting in network congestion, if it is incorrectly configured and not employing the most efficient routing protocol.
When low-priority traffic consumes excessive bandwidth due to improperly designed network devices, it can result in congestion, which delays and reduces network performance for important applications.
Errors in setup lead to problems with network security, which exacerbates congestion. Denial of Service (DoS) attacks, for instance, can occur from a misconfigured firewall that is not preventing malicious traffic, flooding the network with traffic and causing congestion.
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Network Attacks: Network assaults, especially Distributed Denial of Service (DDoS) attacks, can be a significant contributor to network congestion. A denial-of-service attack (DDoS) involves the use of a large number of hacked devices, sometimes known as a "botnet," to flood a target network with data, overloading it and generating congestion.
Attack traffic from DDoS assaults frequently looks like legal traffic, making it challenging for network security devices to distinguish between the two. This makes them extremely challenging to protect against. A denial-of-service attack's massive data volume has the potential to overload a network's capacity, causing congestion and poor performance for genuine traffic.
Congestion may be caused by other kinds of network assaults, especially ones that involve sending a lot of traffic over a network. For instance, in a Ping flood assault, a target device is bombarded with many ICMP echo requests, which renders it unusable. Similar to this, a SYN flood attack includes bombarding a target device with a lot of SYN requests, which uses up its resources and creates congestion.
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Superfluous Traffic: Data packets or information that are sent over a network but do not advance the intended or productive use of the network are referred to as unnecessary traffic. Although every network has a maximum capacity for data, an excessive amount of pointless traffic can clog the network, resulting in poor performance and communication problems.
What does unnecessary network traffic do to slow down networks?
Network congestion can be caused by extraneous traffic in the following ways:
- Use of bandwidth: Extraneous traffic takes up valuable network capacity that may be better used for sending vital data. There is less room for crucial data when the available bandwidth is used up by unnecessary or excessive traffic, which causes transmission speeds and delays to increase.
- Resource exhaustion: The processing and memory capacities of network devices, such as switches and routers, are limited. These devices may run out of resources as a result of processing and managing the high load when needless traffic overloads the network. Consequently, network devices can find it difficult to meet the demand, which could result in congestion and poor performance.
- Increased collisions: Superfluous traffic can cause an increase in collisions in shared network settings, such as Ethernet networks. When several devices try to transmit data at the same time, a collision occurs, which causes data loss and retransmissions. Unnecessary traffic can increase accident rates, resulting in congestion and decreased network performance.
- Buffer overflow: When the receiving end is busy or unable to handle incoming data packets right away, network devices employ buffers to temporarily store them. Buffer overflow, on the other hand, can occur when these buffers are overloaded with needless traffic. Buffer overflows can result in congestion and decreased performance by dropping or delaying incoming packets.
- Routing inefficiencies: The effectiveness of routing methods and procedures can be impacted by superfluous traffic. Routers employ a variety of algorithms to choose the optimal data transmission channel. Nevertheless, routers may squander time and resources trying to analyze and send superfluous data, which might result in less-than-ideal routing choices. Network congestion and latency may worsen as a result of this inefficiency.
Can cyber attacks cause network congestion?
Yes. Cyber attacks, especially Distributed Denial of Service (DDoS) attacks, DoS (Denial of Service), viruses, and malware, can be a significant contributor to network congestion. A denial-of-service attack (DDoS) involves the use of a large number of hacked devices, sometimes known as a "botnet," to flood a target network with data, overloading it and generating congestion. These cyber attacks have the potential to overload the network with excessive traffic, impeding or rendering it impossible for authorized users to access the necessary resources.
How Do You Identify Network Congestion?
How can you tell whether network congestion is preventing your network from functioning properly? You should keep an eye out for the following primary signs of network congestion:
- Sluggish Internet Speeds: When there is network congestion, sluggish Internet speeds are the most noticeable sign. This may show up as sluggish file download speeds, buffering movies, or delayed browser loads.
- Packet Loss: Data packets may be dropped or lost under network congestion, which can result in data transmission failures and even program crashes.
- High Latency: When playing online games or participating in video conferences, network congestion can result in high latency, often known as lag.
- Connection Timeouts: When a network is overloaded, users may not be able to access certain apps or the network as a whole because connections may time out or fail to establish themselves.
- Poor voice or video quality: Congestion might result in blurry or choppy visuals and distorted or missing sound during voice or video connections.
- Unresponsive Applications: Applications that are not responding well on a crowded network might cause users to grow frustrated and lose productivity.
It's probable that congestion is affecting your network if any of these symptoms apply to you. In situations like these, it's advisable to diagnose the problem and attempt to reduce congestion in order to enhance network performance.
What is jitter in networking?
Data packets are transferred from your computer across the internet. They take a certain period of time and are often transmitted at regular intervals. Jitter occurs when these data packets are sent across your network connection with a temporal delay. Route modifications and network congestion are the main causes of this. In essence, jitter can have a detrimental effect on the quality of the audio and video the longer it takes for data packets to arrive. When you're using your computer for leisure, this could be annoying. When you're attempting to connect with the team or have a conference call in a work environment, it might be nearly intolerable. A successful voice-over-internet protocol (VoIP) call can be distinguished from a catastrophic, glitchy one by jitter.
What are the Impacts of Network Congestion?
In order to troubleshoot network congestion before it affects end users or becomes a larger issue that your IT team will have to deal with, it's critical to have a tool that can proactively detect network congestion and perform a network congestion test both inside and outside of your network. Some consequences of network congestion are as follows:
- Slower Data Transmission Speeds: Congestion on the network can lead to packet loss or delay, which slows down data transport and lengthens user wait times.
- Decreased Dependability: Data packets may be discarded or lost as a result of network congestion, which can raise error rates and reduce reliability.
- Decreased Productivity: Applications and services that are delayed or unresponsive due to network congestion can cause a decrease in productivity and a rise in user annoyance.
- Increased Security Risks: A congested network might make it more challenging to identify and address security issues, increasing the chance of cyberattacks on your system since legitimate network activity may become disguised.
- Cost Increases: Expenses associated with network congestion may include higher hardware prices, bandwidth upgrades, or lost time from network disruptions.
- Poor Audio and Video Quality: Users may find it challenging to properly converse or to consume material when there is network congestion, which can result in distorted or choppy audio and video.
- Degraded Performance: Network congestion may lead to sluggish performance, causing websites and programs to load slowly or become unresponsive. Users who depend on certain apps for their jobs may become frustrated when these apps take a long time to load, react, or even crash due to network congestion.
- Diminished Customer Satisfaction: Customers may experience frustration if they have difficulties accessing your website or using your services as a result of network congestion.
How Do You Fix Network Congestion?
Similar to heavy traffic on a freeway during rush hour, network congestion can result in annoying lags and slowdowns. Fear not, though; we've got some advice to help you get through the traffic jams and maintain the seamless operation of your network. Fortunately, you can solve the network congestion problems by taking the following steps:
- Increase Bandwidth: Increasing the amount of available bandwidth is one of the simplest ways to relieve network congestion. This entails expanding the bandwidth provided by your internet service provider or replacing the routers and switches on your network.
- Add Traffic Prioritization: By giving priority to vital applications and restricting the amount of bandwidth allotted to less crucial ones, you may optimize network traffic. Network device Quality of Service (QoS) settings can be used to accomplish this.
- Eliminate Superfluous Traffic: By eliminating superfluous traffic from the network, such as malware or spam, you can lessen network congestion. Firewalls and antivirus software are examples of network security tools that may be used to do this.
- Reconfigure Network Architecture: By dividing your network into several parts for various departments or applications, you may optimize the performance of your network. This may lessen traffic and enhance the functionality of the network as a whole.
- Use Network Monitoring: By giving you real-time access to network traffic, you may spot possible congestion areas and take steps to relieve them. Regularly monitor your network traffic for any unusual activity that could indicate congestion.
- Make Use of Load Balancing: To improve performance and lessen congestion, load balancing divides network traffic among several servers or connections. Specialized hardware or software for load balancing can be used to accomplish this.
How Do You Test Network Congestion?
A network stress test, also known as a network congestion test, is a technique used to evaluate how a network performs when there is a high load, increased traffic, or congestion. Evaluating the network's performance, locating any bottlenecks, and ascertaining how it responds to traffic volumes that may approach or surpass its capacity are the main goals of this kind of testing. The primary steps of network congestion testing are as follows:
- Design of Test Scenarios: Network administrators or testers create particular scenarios to mimic different kinds of network congestion. These scenarios might involve varying traffic volumes, fluctuating network loads, and the introduction of fictitious problems or anomalies.
- Software and Tools for Testing: Typically, network traffic generators and simulators, specialized hardware and software that produce network traffic, are used in network congestion experiments. These technologies are capable of simulating many forms of traffic, such as speech, video, data, and more.
- Generation of Loads: In order to simulate different load levels, the test tools create and inject traffic into the network. The aim is to generate scenarios of congestion that might arise during peak load, average usage, or extraordinary situations.
- Measurement and Monitoring: Throughout the test, a number of network performance parameters are tracked continually, such as throughput, latency, jitter, packet loss, and CPU and memory consumption on network devices. These measurements are useful for evaluating the network's performance during congestion.
- Assessing Network Behavior: Seeing how the network reacts to an increase in load is the main objective of a network congestion test. Testers evaluate variables such as the threshold for network performance degradation, the speed at which the network recovers from congestion, and the presence of performance problems with certain connections or components.
- Determining Bottlenecks: Tests for network congestion can identify bottlenecks in the system, which could be brought on by inadequate bandwidth, overworked network hardware, or other issues. For the purpose of capacity planning and performance improvement, locating these bottlenecks is essential.
- Stress Testing of Networks: in certain instances, tests for network congestion could entail pushing the network to its limits to see how it responds under harsh circumstances. This can assist in locating possible flaws in the infrastructure or architecture of the network.
- Analysis and Reporting: The outcomes of the network congestion test are examined and recorded when it is finished. The report could include suggestions on how to improve network performance, upgrade hardware, or alter the design of the network to deal with congestion problems.
In conclusion, testing for network congestion is an important procedure for evaluating network performance and spotting any problems before they result in a reduction in services or a disruption in the network. It assists businesses in understanding how their network behaves under various load scenarios and informing resource allocation and optimization decisions.
Quality of Service (QoS)
A network method called quality of service, or QoS is used to control quality and provide transmission priorities for data traffic. QoS guarantees that various forms of data traffic, including audio, video, and data, are provided with the proper service levels. Its main goals are to provide dedicated bandwidth, reduce latency, and manage jitter so that networks and organizations may prioritize data. It is essential for enhancing the functionality of service provider networks, wide area networks (WANs), and commercial applications.
Repetitive or non-essential traffic can further exacerbate congestion. When software upgrades or data backups are not planned for off-peak times, for example, they might use up a lot of network resources and slow down other important processes. Prioritizing important data and minimizing the effect of pointless traffic on network congestion may be achieved by effective traffic management, scheduling, and Quality of Service (QoS) policy implementation.
Which Tools for Monitoring and Preventing Network Congestion Can be Used?
One of the most important issues for an IT administrator to handle is network congestion. The best tools to control network congestion for small or large networks are listed below:
1. SolarWinds Bandwidth Analyzer Pack
Network congestion can have many distinct causes, and the finest systems provide insights into every essential component of your network. One of the most complete packages available for locating, examining, and resolving network congestion problems is the SolarWinds bandwidth analyzer bundle (BAP). With BAP, you may receive a comprehensive overview of network performance, including wireless and multi-vendor monitoring.
With its interactive graphs and displays, SolarWinds BAP has the user-friendly interface we've come to expect from the SolarWinds brand. BAP begins with network traffic monitoring, which includes SNMP, NetStream, J-Flow, and other data kinds, in order to address network congestion. By keeping an eye on data pathways, you may see bandwidth bottlenecks immediately and receive notifications based on set criteria. PerfStackTM analytics, a tool exclusive to SolarWinds, enables you to correlate traffic data to determine the underlying cause of congestion. BAP assists you in identifying trends for troubleshooting.
Figure 2. SolarWinds Bandwidth Analyzer Pack
2. SolarWinds NetFlow Traffic Analyzer
One of the components of the initial SolarWinds product is the second one on this list. With an emphasis on bandwidth utilization, the SolarWinds NetFlow Traffic Analyzer (NTA, included in the Network Bandwidth Analyzer Pack) can swiftly gather bandwidth data from your network devices and transform it into clear visuals. You may create traffic reports, check the quality of service (QoS) of your devices, and receive warnings when your bandwidth is low.
Similar to the bandwidth analyzer pack, SolarWinds NTA provides trend analytics through the use of the PerfStack function for network traffic monitoring. When it comes to keeping an eye on network congestion and spotting low bandwidth before it compromises end-user performance, NTA is an invaluable tool.
Figure 3. SolarWinds NetFlow Traffic Analyzer
3. Paessler PRTG Network Monitor
A reputable collection of network monitoring tools, such as real-time measurements for quickly identifying congestion, are offered by the PRTG Network Monitor. The PRTG Network Monitor's capacity to refresh network maps with real-time bandwidth data may be its most distinctive feature. Using the software's map creation function, you may construct a PRTG map of your network and then use it to visually and intuitively monitor devices on the map at all times. All of the main operating systems are compatible with PRTG Network Monitor.
Figure 4. Paessler PRTG Network Monitor
4. Auvik Network Management
You can keep an eye on your network traffic and asset management system on the same platform with Auvik network congestion monitoring. Devices that are capable of auto-discovery may be linked, and as soon as they are operational, you can start receiving real-time traffic information from discoverable devices. Compared to competing services, Auvik requires more manual troubleshooting; your team will still need to find connections by analyzing your own event logs.
Figure 5. Auvik Network Management
5. ManageEngine NetFlow Analyzer
Network traffic may be monitored using NetFlow Analyzer, and problems with network congestion can be resolved with ManageEngine tools. The ability of NetFlow Analyzer to shape traffic for applications only allows you to reroute traffic from crowded regions and stop suspicious packets from being sent, which is a significant advantage. NetFlow Analyzer assists you in creating easily readable performance reports for efficient troubleshooting in addition to traffic monitoring.
Figure 6. ManageEngine NetFlow Analyzer
6. Ipswitch WhatsUp Gold
Even though it's last on the list, WhatsUp Gold is still a complete network solution to network congestion with plenty of benefits. WhatsUp Gold is especially useful for monitoring traffic from applications and monitoring on-premises Windows devices. With alerting and report templates, you can identify and troubleshoot network performance bottlenecks with a user-friendly approach to network traffic management.
Figure 7. Ipswitch WhatsUp Gold