5 Most Common MPLS Issues & How to Fix Them

From 2010 to 2017, MPLS (Multiprotocol Label Switching) was the go-to solution for enterprise networks. It offered reliability, security, and performance that businesses relied on for their critical operations. Since then, many organizations have moved to SD-WAN, attracted by its flexibility and cost-effectiveness. However, MPLS is far from obsolete. Many companies still use MPLS, primarily because of its robust security features or because their existing network gets the job done and they see no need to make a change.

That said, no technology is without its flaws. If you're sticking with MPLS, you’ve likely run into some hiccups along the way. These issues can range from minor inconveniences to major disruptions that affect your entire network.

This article is here to help. We’ll break down the five most common MPLS issues, why they happen, and how you can tackle them.

MPLS is a networking technology that helps efficiently route data between different locations. Instead of relying on traditional IP routing, which requires routers to analyze packet headers at every hop, MPLS uses labels to quickly direct data through pre-determined, high-speed paths. This makes it faster, more reliable, and ideal for businesses that need guaranteed performance for applications like VoIP, video conferencing, and cloud services.

It relies on key components like:

• Label Edge Routers (LERs): These routers add or remove labels as data enters or exits the MPLS network.
• Label Switch Routers (LSRs): They forward data based on labels, ensuring it takes the most efficient path.
• Label Distribution Protocol (LDP): This protocol helps routers share label information and establish efficient routes.

MPLS is widely used by enterprises that prioritize security, reliability, and Quality of Service (QoS). It allows businesses to create private, secure connections between offices, data centers, and remote locations with minimal latency and packet loss.

Even though MPLS offers great benefits, it's not immune to problems. Issues like network congestion, misconfigurations, and latency can impact performance, leading to slow applications, dropped connections, and frustrated users.

Understanding common MPLS issues is crucial because:

• Proactive Troubleshooting: Knowing what to look for helps you catch and fix problems before they escalate.
• Optimized Performance: Addressing issues early ensures your network delivers the speed and reliability your business needs.
• Cost Efficiency: Resolving MPLS issues quickly can prevent costly downtime and avoid unnecessary spending on additional bandwidth or infrastructure.

By identifying and tackling these issues head-on, you can ensure your MPLS network continues to support your business without unexpected surprises. Plus, knowing how to solve these problems can save your business from the costly investment of switching to a new SD-WAN solution.

Let’s be honest – troubleshooting MPLS issues can be a real headache. It’s like deciding to cook a fancy meal after a long day at work. Sure, you could spend hours chopping, prepping, and cooking, but wouldn’t it be easier to just order delivery and enjoy a great meal without the hassle?

At Obkio, we get it. If you don’t feel like diving deep into the endless causes of MPLS problems, manually mapping every network path to track issues, and troubleshooting them the hard way (ugh), we’ve got you covered. Obkio’s MPLS monitoring tool is like ordering your favourite takeout – super quick to deploy, easy to master, and gives you everything you need to keep your MPLS network running smoothly.

We designed Obkio with MPLS networks in mind, drawing from years of experience managing them ourselves. Here’s how Obkio makes MPLS monitoring a breeze:

• End-to-End Monitoring: Obkio continuously monitors every part of your MPLS network using synthetic traffic to ensure it's performing as expected.
• No Packet Capture Needed: Instead of complicated packet analysis, Obkio generates synthetic traffic with the correct DSCP code to match your Class of Service (CoS). This simplifies monitoring while avoiding security risks.
• Instant Alerts for DSCP Mismatches: If the DSCP code isn’t received as expected, Obkio's agents instantly detect and alert you, pinpointing exactly where the issue occurred.
• Proactive Insights: Obkio helps you stay ahead of problems, offering actionable data to fine-tune your network and ensure optimal performance.

So, if you’re feeling a little “lazy”, skip the manual troubleshooting and let Obkio do the heavy lifting. You’ll get the insights you need – without the hours of effort.

• 14-day free trial of all premium features
• Deploy in just 10 minutes
• Monitor performance in all key network locations
• Measure real-time network metrics
• Identify and troubleshoot live network problems

Network congestion is one of the most common MPLS issues that businesses face. It happens when there's more traffic than the network can handle, causing slow performance, packet loss, and frustrated users – kind of like a traffic jam during rush hour. When too many cars hit the road at once, everything slows down, and your smooth commute turns into a nightmare. The same thing happens with your MPLS network when traffic exceeds available bandwidth.

Several factors can contribute to MPLS congestion, including:

• Increased Bandwidth Demand: As businesses grow and adopt more cloud applications, video calls, and data-heavy tools, MPLS networks can struggle to keep up.
• Poor Traffic Prioritization: Without proper QoS (Quality of Service) settings, critical applications might get stuck in traffic with less important data.
• Oversubscription: Many service providers oversubscribe their networks, meaning they allocate more bandwidth than actually available, leading to congestion during peak hours.
• Unexpected Traffic Spikes: A sudden increase in usage – like a large file transfer or a company-wide video call – can overwhelm the network.

Network congestion detected in Obkio's Network Monitoring application

When congestion hits, your MPLS network might experience:

• High Latency: Slower response times that affect real-time applications like VoIP and video conferencing.
• Packet Loss: Critical data might never reach its destination, leading to poor performance and communication breakdowns.
• Jitter: Inconsistent data delivery, causing choppy audio and video.
• Downtime Risks: If congestion isn’t addressed, it can lead to complete service disruptions.

The good news? There are ways to prevent and manage MPLS congestion effectively:

1. Implement QoS Policies: Prioritize mission-critical traffic to ensure smooth performance for essential applications.
2. Monitor Traffic Trends: Use a network monitoring tool to track traffic patterns and identify potential bottlenecks before they become a problem. A tool like Obkio uses synthetic traffic so it can create a load on your network and identify network congestion before it affects real users
3. Upgrade Bandwidth When Needed: If your network is constantly congested, it might be time to consider scaling up your MPLS capacity.
4. Optimize Routing: Ensure traffic is efficiently distributed across the network to avoid overloading specific paths.
5. Identify Rogue Applications: Unnecessary or bandwidth-heavy apps running on the network can be managed or limited to free up resources.

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Quality of Service (QoS) is a key feature of MPLS networks that ensures critical applications – like VoIP calls and video conferencing – get the priority they need. But when QoS settings are misconfigured, it’s like having the wrong traffic signs on a busy highway – emergency vehicles might get stuck in traffic while casual commuters cruise through. This can lead to delays, poor performance, and unhappy users.

QoS is a core part of the MPLS promise, and if it’s not working as it should be, then your MPLS network has not done its job. QoS helps your network prioritize different types of traffic based on their importance. For example:

• Real-time applications (VoIP, video conferencing) require low latency and minimal jitter.
• Business-critical apps (CRM, ERP systems) need consistent bandwidth for smooth operation.
• General web traffic (browsing, emails) can tolerate occasional delays without major impact.

When QoS is working correctly, the right data gets the right priority. But if it’s misconfigured, your high-priority applications might suffer, leading to frustrating delays and poor user experience.

Some of the most common QoS mistakes include:

• Incorrect Traffic Classification: If traffic isn’t classified properly, critical applications might end up in the wrong queue, and experience lag and MPLS routing issues.
• Over-Provisioning Certain Classes: Giving too much priority to one type of traffic can starve other essential applications.
• Ignoring Bandwidth Limits: QoS can’t create bandwidth out of thin air – misconfigured settings may prioritize traffic but still hit bandwidth limitations.
• Mismatched QoS Policies Across Devices: If QoS settings aren’t consistent across your MPLS network, data might lose priority when moving between locations.

Avoiding QoS misconfigurations requires careful planning and regular monitoring. Here’s what you can do:

1. Audit Your QoS Policies Regularly: Review your settings to ensure they align with your current business needs and application requirements.
2. Use Network Monitoring Tools: Modern network monitoring tools, like Obkio, can help verify that your traffic is being prioritized correctly and spot any misconfigurations.
3. Standardize QoS Across the Network: Ensure all devices and locations follow the same QoS policies to avoid inconsistencies.
4. Test and Adjust: Continuously monitor network performance and adjust QoS settings based on real-world usage patterns.
5. Implement DSCP Monitoring: Use a proactive monitoring tool to validate DSCP tags and ensure packets are being classified correctly throughout the network.

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Differentiated Services Code Point (DSCP) is a key part of MPLS networks that helps prioritize traffic and ensure Quality of Service is maintained across the network. But when DSCP values don’t match across different network devices, it’s like a relay race where one runner drops the baton – critical traffic can lose its priority, leading to delays, packet loss, and poor performance for applications like VoIP and video conferencing.

DSCP is a field in the IP packet header that assigns a priority level to network traffic. It tells MPLS routers how to handle different types of traffic, ensuring high-priority applications get the attention they need. For example:

• VoIP calls: Require high priority for low latency and jitter.
• Business applications: Need consistent bandwidth for reliable performance.
• Bulk data transfers: Can tolerate delays without major impact.

When DSCP values are correctly set across the MPLS network, traffic flows smoothly. But when mismatches occur, traffic can end up being treated as a lower priority or even dropped entirely.

DSCP mismatches can happen due to several reasons, including:

• Inconsistent QoS Policies: Different devices along the network path may have conflicting QoS configurations.
• Misconfigured Routers or Switches: Some network devices may strip or incorrectly rewrite DSCP values.
• Carrier Interference: Your MPLS provider may not honour DSCP tags or may overwrite them with their own policies.
• Traffic Routing Changes: Changes in network paths can expose traffic to devices that aren't properly configured for DSCP handling.

To ensure consistent traffic prioritization across your MPLS network, consider the following best practices:

1. Monitor DSCP Values End-to-End: Use an MPLS monitoring tool to continuously check if DSCP values are preserved throughout the network.
2. Standardize QoS Policies: Ensure that all routers and switches across your network follow the same QoS settings to maintain consistency.
3. Work Closely with Your MPLS Provider: Confirm that your provider honours your DSCP markings and aligns policies accordingly.
4. Regular Audits and Testing: Periodically review and test DSCP settings to detect any mismatches before they impact performance.
5. Automated Alerts for Mismatches: Set up real-time alerts if DSCP values are not properly maintained, helping you quickly pinpoint and resolve issues.

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Packet loss and latency are two of the biggest challenges in any network, and MPLS is no exception. When packets go missing or take too long to reach their destination, it can seriously impact performance – especially for real-time applications like VoIP calls, video conferencing, and cloud-based services. Imagine you're on an important video call, and the audio keeps cutting out or lagging – that’s packet loss and latency at work.

MPLS networks are designed to optimize traffic flow by using label switching to route packets along predetermined paths. This can reduce congestion and improve delivery times compared to traditional IP routing. However, MPLS still faces challenges when:

• Network congestion overwhelms available bandwidth.
• QoS misconfigurations fail to prioritize critical traffic.
• Link failures force packets to take longer, less efficient routes.
• Carrier network issues introduce unpredictable delays.

When any of these factors come into play, packets may be delayed (latency) or dropped entirely (packet loss), leading to performance degradation.

Both packet loss and latency can have a major impact on business operations:

• VoIP Calls: Increased latency results in audio delays and echo, while packet loss causes choppy or missing audio.
• Video Streaming: High latency leads to buffering, and packet loss results in pixelation and frame drops.
• Cloud Applications: Delays in data delivery can affect productivity and the responsiveness of critical apps.
• File Transfers: Large file uploads or downloads may take longer or fail entirely if too many packets are lost.

The best way to address packet loss and latency is through proactive monitoring and optimization. Here’s how you can tackle these issues:

1. Deploy End-to-End Monitoring: Tools like Obkio continuously test your MPLS network using synthetic traffic, allowing you to spot latency spikes and packet loss as they happen.
2. Analyze Performance Trends: Regular monitoring helps identify patterns, so you can detect recurring congestion or misconfigurations.
3. Set Up Alerts for Critical Issues: Configure instant notifications when packet loss or latency exceeds acceptable thresholds, allowing you to take quick action.
4. Test QoS Policies: Ensuring that your traffic is prioritized correctly helps minimize latency for high-priority applications.
5. Collaborate with Your Provider: If persistent latency or packet loss occurs, having performance data from a monitoring tool can help you work with your MPLS provider to resolve issues faster.

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Link failures in MPLS networks can bring operations to a grinding halt, causing service disruptions, performance degradation, and even downtime. Whether it's a physical issue like a fibre cut or a logical failure due to misconfigurations, these problems can have a significant impact on business-critical applications.

Imagine you're working on an important project in the cloud, and suddenly, everything freezes. Your connection drops and productivity takes a hit – that's a link failure in action.

In an MPLS network, link failures occur when a connection between two network nodes is disrupted. This can happen at various points within the network, affecting data flow between branch offices, data centers, and cloud services.

When an MPLS link fails, traffic must be rerouted through alternate paths, which can increase latency, cause congestion, and impact overall performance. In worst-case scenarios, if redundancy isn't properly configured, traffic may not be able to reroute at all.

Link failures can stem from several factors, including:

• Physical Issues:

  • Fibre optic cable cuts
  • Hardware malfunctions (e.g., router or switch failure)
  • Power outages affecting networking equipment

• Logical Issues:

  • Misconfigured routing policies
  • Software bugs or firmware glitches
  • Human errors during network changes

• Carrier-Side Problems:

  • ISP outages or maintenance
  • BGP route changes impacting MPLS paths
  • Congestion leading to degraded performance

Regardless of the cause, link failures can lead to packet loss, increased latency, and interruptions in critical services like VoIP, video conferencing, and cloud-based applications.

Detecting link failures quickly is crucial to minimizing downtime and maintaining a seamless user experience. Here’s how you can stay on top of link issues:

1. Continuous Network Monitoring:

Use a proactive monitoring tool to continuously check your MPLS links for availability and performance.

2. Automated Alerts and Failover:

Set up real-time alerts to notify your team as soon as a link goes down so you can act immediately. Ensure proper failover mechanisms are in place to reroute traffic with minimal disruption.

3. Historical Performance Analysis:

Analyze historical data to identify recurring link failures and work with your MPLS provider to address underlying issues.

4. Testing Redundancy and Backup Links:

Regularly test your backup connections to ensure they can handle traffic if the primary link fails.

If you want to learn about 5 more common MPLS network issues and how to tackle them, check out our article: How to Monitor MPLS Networks.

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Staying on top of MPLS network issues doesn't have to be a headache. With the right approach and tools, you can quickly detect and resolve problems before they impact your business. Here’s a step-by-step guide to proactively monitoring and troubleshooting your MPLS network with Obkio’s Private Network & MPLS Network Monitoring Tool.

Getting started with Obkio is effortless. With a free 14-day trial and an intuitive onboarding wizard, you can deploy MPLS monitoring in just 10 minutes – no technical expertise required! Whether you're an IT pro or a beginner, Obkio makes it easy to monitor your network’s performance.

How to Deploy Obkio for MPLS Monitoring:

• Install Monitoring Agents: Deploy agents at each MPLS site to continuously monitor performance.
• Configure DSCP Templates: Easily set up monitoring for different Classes of Service (CoS) by duplicating and adjusting standard templates.
• Optimize with Ease: Obkio’s solution is built for MPLS, providing a straightforward setup that delivers instant value.

Once Obkio is set up, it starts generating synthetic traffic across your MPLS network, using the correct DSCP codes to match your CoS settings. This ensures accurate performance tracking without the complexity of packet capture.

Obkio continuously tracks key metrics to help you stay ahead of potential issues:

• Latency: Measures how long data takes to travel across the network.
• Packet Loss: Identifies dropped packets that could degrade performance.
• Jitter: Tracks fluctuations in packet delivery times, crucial for voice and video applications.
• Bandwidth Utilization: This helps you understand how much of your available bandwidth is being used.

QoS and DSCP settings are critical for MPLS performance. However, misconfigurations can cause serious issues, often going unnoticed until congestion occurs.

With Obkio, you can:

• Monitor DSCP propagation across your network.
• Detect mismatches between customer-tagged and MSP-tagged packets.
• Gain visibility into your network, even when your MSP provides limited insights.

The first step in resolving MPLS issues is identifying whether the problem lies within your internal network or your MSP’s infrastructure.

• Internal Issues: If the issue is within your network, Obkio provides detailed insights to help you troubleshoot misconfigurations, routing issues, and QoS settings.
• External Issues: If the problem lies with your MSP, Obkio equips you with concrete data and traceroute reports to escalate the issue effectively.

If you're facing MPLS performance problems, Obkio’s tools provide the necessary insights to resolve them efficiently:

• Validate QoS Settings: Ensure traffic is prioritized correctly.
• Check DSCP Tags: Confirm packets are tagged properly for accurate traffic handling.
• Analyze Traffic Queues: Identify congestion points in different CoS buckets.
• Engage Your MSP: Use reports and Obkio’s visual traceroutes to pinpoint external issues and speed up resolution with your service provider.

MPLS networks require ongoing monitoring to prevent recurring issues. Obkio’s proactive approach helps you stay ahead by:

• Sending real-time alerts when performance degrades.
• Providing automated reports to track trends and detect patterns over time.
• Offering a visual dashboard for quick insights into your network’s health.

With Obkio, you get full visibility into your MPLS network – ensuring your business stays online and optimized without the hassle.

Your MPLS network is the backbone of your business operations – powering everything from critical applications to seamless communication across locations. But here’s the thing: left unchecked, they can quietly introduce issues that disrupt productivity, frustrate users, and cost your business valuable time and money.

The good news? You don’t have to play the waiting game. By proactively monitoring and diagnosing MPLS performance with the right tool like Obkio, you’re not just solving problems; you’re preventing them. No more scrambling to troubleshoot when users complain. No more vague responses from your MSP. Just clear, actionable insights that keep your network in top shape – always.

So, why wait until the next outage? Take the first step now. Set up Obkio in minutes, gain total visibility, and take control of your MPLS performance before it takes control of you.

Start your free 14-day trial today and experience the difference.