Jitter monitoring with PRTG:
Say goodbye to delays!

  • PRTG monitors quality of service
  • PRTG monitors jitter and other values
  • Customizable, fast-acting alarm
  • React quickly to prevent malfunctions
  • Cisco monitoring included

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  • Unlimited version of PRTG for 30 days
  • After 30 days, PRTG reverts to a free version
  • Or, you can upgrade to a paid license anytime

Congestion on the line: A single packet is enough


Many companies swear by VoIP (Voice over Internet Protocol). But if a problem occurs during the transmission of data packets, then the protocol is in danger of malfunctioning. One single delayed data packet can cause noticeable delays and transmission errors. These deviations, known as "jitter,” can be promptly detected and continuously monitored by PRTG. With PRTG, you can react quickly – and therefore prevent interruptions and malfunctions from arising.

Some sensors to help you get started with jitter monitoring



iWhat is a sensor?

In PRTG, “Sensors” are the basic monitoring elements. One sensor usually monitors one measured value in your network, e.g. the traffic of a switch port, the CPU load of a server, the free space of a disk drive. On average you need about 5-10 sensors per device or one sensor per switch port.

View video (3:26 min.)

QoS Round Trip Sensor

QoS Round Trip Sensor

PRTG’s QoS Roundtrip Sensor monitors the quality of your network connection. This sensor measures (or calculates) and displays jitter, latency, packet loss, and MOS (mean opinion score). The jitter value presents the minimum, maximum, and average deviations in milliseconds.

QoS One Way Sensor

QoS One Way Sensor

The QoS One Way Sensor monitors the quality of the connection between two PRTG probes. The jitter value (minimum, maximum, average) is also displayed by this sensor.

Cisco IP SLA Sensor

Cisco IP SLA Sensor

Cisco devices (e.g. routers and switches) cause jitter to rise. The Cisco IP SLA Sensor uses SNMP to monitor the Cisco IP Service Level Agreement (SLA). This sensor is perfect for reading and displaying the jitter value. Cisco IP SLA monitoring is included with PRTG at no extra charge! 

Ping Jitter Sensor

Ping Jitter Sensor

The Ping Jitter Sensor calculates jitter for a series of ping signals. With ping monitoring, you can check the availability of all your network devices.


i Ping is a command-line utility, available on virtually any operating system with network connectivity, that acts as a test to see if a networked device is reachable. The ping command sends a request over the network to a specific device. A successful ping results in a response from the computer that was pinged back to the originating computer. Read more ...

A sneak peek at VoIP monitoring with PRTG


The advantages of using PRTG to measure jitter


Stable VoIP

Stable VoIP

In companies that use VoIP, employees are unable to work unless the network is stable. Provide for optimal network stability by monitoring your VoIP with PRTG. By doing so, you’ll make sure your coworkers are able to work efficiently and without interruption.

No extra charges

No extra charges

PRTG is all-inclusive. Choose a license and get access to all PRTG sensors, as well as the alarm, dashboard, and support features. The above-mentioned Cisco IP SLA Sensor is also included at no extra charge. Start out with the free trial version to get a feel for PRTG with no strings attached.

Fast-acting alarm

Fast-acting alarm

PRTG stands out from other monitoring tools in that all its values are customizable. It immediately notifies you in the event of a problem, so you can react quickly – before noticeable interruptions or crashes arise. Thanks to PRTG, you’ll lift a huge weight off the shoulders of your support team, for fewer and fewer of your coworkers will have incidents to report.

PRTG simplifies your day

Our monitoring software works for you and promptly notifies you of potential issues.
It frees you to concentrate on your day-to-day tasks with peace of mind.


PRTG saves time

With PRTG, you get one central monitoring tool for your servers and entire network. Enjoy a quick overview of your whole infrastructure via our dashboard and app.

PRTG saves worry

Customizing PRTG is a breeze. Getting started or switching from another network monitoring tool is easy thanks to the PRTG auto-discovery and pre-configured device templates.

PRTG saves money

80% of our customers report substantial or even exceptional cost savings in the area of network monitoring. The experience shows that the costs for licenses have paid for themselves within a matter of weeks.


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trust our software. Every day.

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  • Unlimited version of PRTG for 30 days
  • After 30 days, PRTG reverts to a free version
  • Or, you can upgrade to a paid license anytime

4 key factors for optimizing quality of service


Monitor latency

Monitor latency

How much time does a data packet need for its "trip” from the sender to the receiver? This time is referred to as latency. According to ITU-T, the agency responsible for telecommunications standards, latencies of up to 125 milliseconds are acceptable. PRTG’s recommendation: Set a threshold for 100 milliseconds. You’ll immediately receive an alert if this value is exceeded, allowing you to act quickly before noticeable interruptions or crashes arise.

Monitor jitter

Monitor jitter

Jitter is used to measure the deviation from your average latency. PRTG suggests this value be a little less than 20 milliseconds, which is also lower than the amount recommended by the standard. And the following applies here too: the sooner you learn of these deviations, the faster you can do something about them.

Monitor packet loss

Monitor packet loss

Packet loss is often responsible for problems with VoIP. Packets can get lost, or arrive as duplicates or in the wrong order. PRTG shows all three variations. We recommend setting your loss rate threshold at 0%, for just one lost packet can cause an error message or lead to a malfunction.

Calculate mean opinion score (MOS)

Calculate mean opinion score (MOS)

MOS is used to express the quality of a call. This score is based on jitter, latency, and other parameters. As a compilation of values, MOS offers a quick overview of the status of your VoIP.

Practical tip: “Hey Stephan, do you have any tips for VoIP monitoring?”

“To simulate a telephone that uses the same network as your real IP telephone, simply set up our QoS Reflector Script on a Raspberry Pi and connect the latter to the desired point on the network. By doing so, you can guarantee that you are measuring the right network path with our QoS Round Trip Sensor. This is important because VoIP traffic is usually treated with priority.”

Stephan Linke, technical support at Paessler AG

The short and sweet of it:
All you need to know about jitter


What is jitter?

Data packets are transmitted at a certain speed. A sender sends packets to a receiver in millisecond intervals. Jitter occurs when this interval gets off track, leading to deviations or irregularities in runtime. The term "jitter” means fluctuation, oscillation, or a variation in frequency. 

What happens if jitter is too high?

If data packets reach a receiver at irregular intervals, then loopholes emerge. As a result, data can no longer be circulated on a continual basis. While this may not be a big deal for web or email applications, it can cause interruptions in phone and video calls for companies who use VoIP. You’re also likely to encounter glitches at home when running real-time applications such as videos or computer games.

What causes jitter?

One example of how jitter can spike is when a data line is heavily strained, causing bottlenecks to appear in intermediate devices. In such a case, your available bandwidth is usually not sufficient (make a bandwidth test). High jitter can also be caused by data congestion in switches and routers. PRTG promptly alerts you if your hardware is overstrained, so you can intervene quickly – before your system malfunctions.


iBandwidth is measured as the amount of data that can be transferred from one point to another within a network in a specific amount of time. Typically, bandwidth is expressed as a bitrate and measured in bits per second (bps). It refers to the transmission capacity of a connection and is an important factor when determining the quality and speed of a network.   Read more ...


How do I eliminate jitter?

If jitter is high, then you may want to increase your bandwidth. Usually, however, this comes at an additional charge. As an alternative, you can give higher priority to VoIP than to other data packets, such as emails.

How is jitter calculated?

Jitter is calculated mathematically and in a standardized fashion. The IETF has outlined its jitter calculation method in RFC 3550. PRTG uses this protocol to calculate jitter.

How can I perform a jitter test?

Use the above-mentioned PRTG sensors to determine your jitter value. These preconfigured sensors are extremely quick and easy to use. You won’t need to do any trial runs to get started.

Does it make sense to perform a jitter test?

Individual jitter tests are relatively inconsequential, for they only enable you to see if deviations occur during a specific period of time. What’s important is continuous monitoring, as this is the best way to recognize recurring patterns and get to the root of problems.



You want to know more about other network-related monitoring topics?

Here you find everything about...

PRTG as network traffic analyzer

PRTG the network activity monitor

PRTG as network diagnostics tool

Network security monitoring with PRTG

Over 95% of our customers recommend PRTG


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The aim was to tune the network monitoring software closer to the needs of the administrators.
The result of the survey: over 95% of the participants would recommend PRTG - or already had.

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PRTG: The swiss army knife for sys admins

Adapt PRTG individually and dynamically to your needs relying on a strong API:

  • HTTP API: Access monitoring data and manipulate monitoring objects using HTTP requests
  • Custom Sensors: Create your own sensors for customized monitoring
  • Custom Notifications: Create your own notifications to send alarms to external systems
  • New REST API Sensor: Monitor almost everything that provides XML or JSON


Other jitter-related topics

VoIP Monitoring

PRTG monitors VoIP call quality and performs VoIP latency tests. PRTG alerts you quickly so you can stop problems in their tracks. Learn more about using PRTG as VoIP monitoring software here.

Bandwidth Monitoring

How stable is your bandwidth? Find out why your system is slow, and where there is room for improvement. PRTG uses SNMP, packet sniffing, and NetFlow, jFlow, sFlow to monitor bandwidth.

More on bandwidth monitoring

QoS Monitoring

As described above, optimal quality of service is the basis for high-performance VoIP calls. Find additional information on quality of service and QoS monitoring with PRTG here

Packet Capture

PRTG analyzes data packets in real time and displays the data packet loss rate. In the event a critical value is exceeded, you’ll automatically receive an alert.

More on packet capture

German quality engineering




Free Download
  • Unlimited version of PRTG for 30 days
  • After 30 days, PRTG reverts to a free version
  • Or, you can upgrade to a paid license anytime

Most administrators want to test a tool for free before deciding to make an investment.

The many advantages of PRTG:

1. Free trial version: Take the time to explore PRTG so you can determine if it satisfies your needs and meets your expectations. Once the trial is over, it’s easy to upgrade your already configured version of PRTG, which means you’re much less likely to make an incorrect purchase.

2. One tool, one overview: Administrators often use a variety of monitoring solutions for their network or for the individual components of their infrastructure. But using several different tools every time you want to create an overview costs time and energy. PRTG is an “all-in-one” solution. Our dashboard and app provide a comprehensive overview, whenever you want it.

3. Quick customer support: Got a question? Stuck on a problem and need a hand? PRTG is backed by a dedicated development and support team. We do our utmost to answer every customer inquiry within 24 hours (on business days). Browse all our support topics here.

Configure your PRTG today. The trial version is free of charge. Save time, worry, and money with our monitoring tool designed for your network and entire infrastructure.



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