How To Fix Bandwidth Issues: Detect, Diagnose & Solve Your Network Congestion

Network bandwidth has always been a precious commodity and given our current circumstances with so many people working from home, many companies have not had the bandwidth they need in the right places. This blog will help you with some strategies on how to detect bandwidth issues, further diagnose those issues, and what actions you can take to relieve those bandwidth issues.

Detecting network bandwidth issues through congestion management.

Most issues related to network bandwidth will present as congestion, that is there is not enough bandwidth to satisfy the demands of the users and applications. Users will report that “some application” doesn’t work like it did yesterday. After you have confirmed the application is up, and the user reports are correct, where do you look next?Check the network:

1. Monitor the helpdesk cases raised in particular where users are reporting problems with applications across the network. Knowing whether this is from a branch, remote site or from home (will shorten troubleshooting), it is likely to indicate network congestion.
2. Monitor utilisation of network links and raise alerts when bandwidth becomes heavily utilised.
3. Make sure you monitor packet discards and errors.
4. And finally, monitor Quality of Service (QoS) parameters available in the network device; in particular, you are looking for where QoS caused packet loss.

The first step to detection is to get NMIS installed and let it start collecting data NOW. DOWNLOAD NMIS

Diagnosing Network Bandwidth Issues

What issues are being reported by users about the network or internet speed, is the application slow due to a slow internet connection or is it unusable? For example, is there a problem with voice over IP or video conferencing? Does it occur during file transfers? Are they connected with a wired connection va an ethernet cable or by Wi-Fi? Is bandwidth throttling being used? The more qualified information you get from your helpdesk, the faster you can get to work.By monitoring the network for issues related to congestion, you are ready to start further diagnosis to determine what is causing those issues and look for possible solutions to avoid the congestion firstly or control it secondly.

Depending on the tools available to you, you should have an idea of those causes. For example, putting aside transmission, format errors, or device health issues packet discards will generally be caused by QoS classes dropping packets, so the solution is to refine the QoS configuration to prevent the desired traffic from being discarded.

Depending on the application, the dropped packets will be causing retransmissions if they are using TCP, while voice and video symptoms are voice clipping or slow refreshing video or video and voice not keeping sync.

Depending on the wired connections or wireless devices and operating systems being used, you should be able to see key performance indicators for this, which will be collected by your monitoring system, like NMIS.  For example you could monitor for TCP retransmissions on servers, this would indicate issues with internet bandwidth performance or low bandwidth for those applications.

Using systems like Cisco IPSLA are a great way to monitor for changes in latency or variability in latency (Jitter).  NMIS can collect your IPSLA data, providing graphs as well as alerts when it detects issues.

Monitoring these metrics will guide where you need to look deeper, you might need to collect more detailed information from the devices to determine what the issues are, e.g. looking at command outputs for QoS or interface information to decide what changes are available to resolve the helpdesk reports.

If you identify the QoS Classes which are exceeding their configuration limits with resulting packet loss, you will need to consider changing the bandwidth allocations for those classes, increasing the available bandwidth for voice and video, for example.

HOW TO DIAGNOSE: Use NMIS and opConfig to collect data, which can then be analysed. 

OPA can help with the detection and diagnosis of congestion problems.

Actions to fix network bandwidth problems

Ultimately to fix a bandwidth issue, you should upgrade the overall capacity at the site. If you are not able to upgrade or need to buy time, then implementing QoS features to manage which traffic is less important to the business and have it shaped or dropped during times of congestion.

Contrary to popular belief, QoS does not create more throughput. It does create better “goodput,” with critical applications protected, and applications that are hogging bandwidth, controlled.

Two standard policy options for QoS are shape or police. Policing will ensure bandwidth is never exceeded and drop the offending traffic. Shaping will delay traffic to smooth out the traffic over time. Note that as shaping limits are exceeded, it may result in dropped traffic.

Talk to us about how our solutions can give you the insight you need to make data-based decisions. You’ll reduce helpdesk stress, own your infrastructure all while improving the user experience.

Frequently Asked Questions

What is the main issue related to network bandwidth?

The main issue related to network bandwidth is congestion, where there is not enough bandwidth to satisfy the demands of the users and applications.

This can result in slow or unusable applications, dropped packets, retransmissions, and issues with voice and video quality.

With so many people working from home, many companies have struggled to have the necessary bandwidth in the right places to support their employees.

To detect, diagnose, and fix network bandwidth issues, it is important to monitor network utilization, packet discards and errors, and Quality of Service (QoS) parameters.

How can I detect issues with my network bandwidth?

To detect bandwidth issues, you can monitor helpdesk cases raised by users reporting problems with applications across the network.

You can also monitor the utilization of network links and raise alerts when bandwidth becomes heavily utilized, monitor packet discards and errors and monitor Quality of Service (QoS) parameters available in the network device.

For a better, and more automated approach, installing NMIS and letting devices connected to it start collecting data can also help in detecting network bandwidth issues.

What is NMIS?

NMIS (Network Management Information System) is a comprehensive network management system that assists with fault, performance, and configuration management.

It provides performance graphs and threshold alerting, as well as customizable notification policies with different types of notification methods.

NMIS monitors the status and performance of an organization’s IT environment, identifies faults and assists in their rectification, and provides valuable information for IT departments to plan expenditures and IT changes.

It features a sophisticated business rules engine, automated health live baselining, configurable alert thresholds, policy-based actions, escalations, and planned outage management.

NMIS is customizable, scalable, and has pre-configured out-of-the-box solutions, and can be used by Telco and Internet Service Providers, enterprises, and governments.

It offers community support and has predictable and transparent pricing that scales with the user’s requirements.

How can I diagnose issues with my network bandwidth?

Diagnosing network bandwidth issues requires gathering qualified information from your helpdesk and monitoring the network for issues related to congestion.

Depending on the tools available to you, you can determine the causes of the issues.

For example, packet discards will generally be caused by QoS classes dropping packets, so refining the QoS configuration to prevent the desired traffic from being discarded can solve the issue.

Using systems like Cisco IPSLA can also help monitor for changes in latency or variability in latency (Jitter).

What is QoS?

QoS stands for Quality of Service. It is a set of techniques and mechanisms that aim to ensure that network traffic is prioritized according to certain criteria in order to meet the requirements of different applications and users.

QoS mechanisms are used to manage network congestion, reduce latency, and ensure that important applications receive the necessary bandwidth and resources.

QoS can be used to prioritize different types of traffic, such as voice and video, over other types of traffic, such as file transfers and email.

This is done by assigning different levels of priority to different types of traffic and using mechanisms such as traffic shaping and prioritization to ensure that higher-priority traffic is given preferential treatment.

QoS is particularly important in real-time applications such as voice and video conferencing, where delays or dropped packets can seriously affect the quality of the service.

QoS mechanisms can help to ensure that these types of applications receive the necessary resources and are not affected by other types of traffic on the network.

Overall, QoS is an important tool for network administrators to manage and prioritize network traffic, ensuring that important applications and services receive the necessary resources and perform as expected.

What are the steps to fix issues with network bandwidth?

Actions to fix network bandwidth problems include upgrading the overall capacity at the site or implementing QoS features to manage which traffic is less important to the business and have it shaped or dropped during times of congestion.

QoS does not create more throughput but creates better “goodput,” with critical applications protected, and applications that are hogging bandwidth controlled.

Two standard policy options for QoS are shape or police, with shaping delaying traffic to smooth out the traffic over time, and policing ensuring bandwidth utilization is never exceeded and drops the offending traffic.

It’s worth noting that while QoS can help control bandwidth usage, it does not create more throughput.

However, it does create better “goodput,” with critical applications protected and non-critical applications controlled.