Packet Loss

Packet loss has always been a contentious topic in the networking industry. It remains a critical consideration in the design and implementation of networks, primarily due to its direct impact on network efficiency and overall performance. Even a single faulty device or a misconfigured setting can lead to packet loss, significantly affecting the entire network’s performance.

Packet Loss in Networks

Packet loss refers to the scenario where a device sends a specific amount (or “packets”) of data over a network, and a considerable portion of this data is lost or “dropped” along the route. This implies that any data sent over the network does not fully reach the destination device. Network packet loss is a key issue that vendors are still striving to resolve and is something all network administrators must keep in mind when implementing network architectures or troubleshooting network issues.

Causes of Packet Loss

Understanding the reasons behind packet loss in a network is crucial for addressing these issues. Network packet loss primarily occurs due to one or a combination of the following reasons:

• Network Congestion: If your network experiences high traffic, routers may start dropping packets to keep up.
• Wireless Network Issues: Wireless networks and devices tend to have relatively high packet loss rates. If your network infrastructure involves many wireless devices, your packet loss rate may be higher than usual.
• Overloaded Network Devices: When network devices handle loads beyond their designed capacity, packet loss is one of the initial impacts observed. These devices cannot process the data volume and begin dropping packets at a rate that disrupts the entire network’s data flow.
• Improper Network Configuration: A misconfiguration in a switch can lead to network loops, causing broadcast storms that essentially cripple the network. During these storms, network devices start dropping packets due to overload.
• Potential Security Vulnerabilities: Sometimes, when network vulnerabilities are exploited, hackers may attempt to flood the network with a massive number of packets in a Distributed Denial of Service (DDoS) attack. Although this is rare, it’s best practice to check for vulnerabilities when experiencing high packet loss rates.

Impacts of Packet Loss

The most direct impact of network packet loss is an increase in network connection latency. Latency can be defined as the total time it takes for a packet to travel from the source device to the destination device and back. Unlike ping, which is just the time a device takes to reach another on the network, latency is a round-trip value.

When latency increases, the network quality relative to the affected devices drops sharply. This is self-explanatory; when the time required to send packets increases, the time to send the entire data also increases proportionally, affecting data transfer rates. In VoIP and video data transmission, the impact of packet loss is very pronounced, as these are real-time processes. High packet loss rates can cause significant issues. It can also be seen when transferring large files over the network, as latency multiplies across thousands of packets and slows down the transfer itself.

How to Detect/Check Packet Loss

Using reliable network packet loss testing tools to detect packet loss is crucial for identifying the root cause of the issue, especially in WAN and Wi-Fi networks. Issues like jitter due to network congestion, data transmission loss due to outdated device hardware, and delays in VoIP calls or video conferences are primary packet loss problems network administrators face daily. Testing network packet loss helps administrators determine whether the issue is due to packet loss or other network-related problems.

While packet loss can be detected through various network assessment tools like ping and network packet loss monitors, ping works by sending packets to a target device and looking for responses. In other words, packet drop can be detected by measuring the number of packets sent but not received. Failed responses lead to packet loss, and any packet loss exceeding 5% is worth investigating.

How to Fix Packet Loss Issues

When packet loss occurs, administrators need to follow these basic steps to fix the packet loss issue:

• Restart Device Hardware: The universal first line of network troubleshooting is to restart the device’s hardware. While it doesn’t solve all problems, it often works, especially when packet loss in the network is due to technical glitches or errors. After restarting the hardware devices, test the network for packet loss using a reliable packet loss testing tool.
• Replace Outdated Network Hardware: Outdated network hardware struggles to adapt to advanced computing technologies or handle massive network demands, leading to packet loss. Consider upgrading or replacing network switches, routers, and other hardware to enhance network performance and minimize packet loss issues.
• Update Device Software and Drivers: If only one device is facing issues, consider updating its software, device drivers, and firmware to ensure there are no bugs in the operating system causing network packet loss. This also applies to wireless access points and other network components.
• Optimize Network Traffic: Packet loss due to traffic overload can be addressed by optimizing network configurations. Utilize Quality of Service (QoS) settings and allocate appropriate bandwidth to prioritize critical traffic and applications, managing resources effectively.
• Use VPNs: The secure encryption used by VPNs helps reduce the impact of packet loss, especially if it occurs over the Internet. This further enhances network communication performance.

How to Reduce Packet Loss in Networks

While completely avoiding packet loss is practically impossible, here are some best practices to control packet loss rates in your network. Try and implement as many of these suggestions as possible:

• Check All Physical Network Connections and Ports: Ensure they are not visibly damaged and are in good condition.
• Audit All Network Device Configurations: Ensure they do not create any network loops, keeping packet loss due to loops low and avoiding potential bottlenecks.
• Use Comprehensive Network Monitoring Applications: Continuously monitor your devices to keep them well within performance limits.
• Limit the Number of Wireless Connections: Whenever possible, always use wired connections, which help reduce network latency and packet loss due to wireless networks.

Network Packet Loss Monitoring Tools

OpManager uses the Internet Control Message Protocol (ICMP) ping to measure network packet loss, including sending pings between hosts every second and calculating the number of requests lost. Accurate measurement of real-time and historical packet loss helps end-users ensure their network performance meets expectations.

Using network packet loss monitoring tools, administrators can perform:

• Availability Monitoring
• Error and Drop Monitoring
• Monitoring Configuration Changes
• Threshold-Based Intelligent Alerts
• Packet Loss Monitoring on WAN

Availability Monitoring

OpManager pings all monitored devices at defined intervals. If any device experiences significant packet loss, administrators are immediately notified via email or SMS, checking network availability.

Error and Drop Monitoring

All network devices drop packets based on their memory, which can affect performance. These issues are common in routers and switches. Excessive packet drops can indicate problems with the switch or devices interacting with it. Insufficient bandwidth allocation is also a cause of packet loss. Network errors can be diverse; they may result from DNS issues, TCP timeouts, or unresponsive servers. Switches or routers may misinterpret packets due to protocol mismatches during device configuration updates. Network packet loss monitoring tools help administrators monitor and reduce packet loss due to errors and drops.

Monitoring Configuration Changes

Managing all configuration changes on network devices using the Network Configuration Manager plugin helps administrators:

• Schedule Configuration Backups: Restore trusted configuration versions with a single click.
• Detect Changes in Real-Time: Understand the “who,” “what,” and “when” of configuration changes.
• Block Unauthorized Configuration Changes: Use approval workflows.
• Ensure Full Security and Compliance: For every configuration change.

Threshold-Based Intelligent Alerts

In OpManager, separate alerts for packet loss inform administrators when packet loss instances exist in the system and which device is responsible. These threshold-based alerts enable administrators to:

• Specify Thresholds: Receive notifications when packet loss reaches limits, allowing administrators to take appropriate steps to avoid them.
• Configure Incremental or Decremental Thresholds: For packet loss.
• Add More Intelligence to Threshold Configurations: Specify the number of violations allowed before triggering an alert, allowing administrators to implement bulk threshold configurations.
• Clear Alerts by Specifying Reset Values: Avoid false alarms.

Packet Loss Monitoring on WAN

Wide Area Networks (WANs) are prone to network congestion during heavy usage. When different traffic competes for limited shared resources, packets are inevitably dropped or delivered out of order, leading to packet loss. The process of using packet loss monitoring software to track key metrics to avoid packet loss in WAN communication is called network packet loss monitoring.

WAN monitoring features can be used as network packet loss monitors, enabling businesses to enjoy the benefits of shared WAN without compromising performance, including cost-effective bandwidth.

• Precisely Locate WAN Packet Loss Issues: It identifies disruptions between two network stations by performing traceroute operations to obtain necessary information about packet loss. This network packet loss monitoring tool helps administrators drill down and precisely locate the hop where the disruption occurs.
• Configure and Resolve Threshold Conflict Issues: Configure packet loss thresholds, and administrators can also use the tool to generate visual reports on threshold violations, making informed decisions to avoid network packet loss.