This section goes through some of the most typical special situations that the users can face when performing measurements with Qosium. Hints and solution proposals are given on how to proceed.

1. Dealing with a Failure #

Failing to get sensible measurement results is not a reason to feel ashamed. We do it too, on a rather regular basis. While we have worked hard to make Qosium as easy and intuitive to use, the concept of passive network measurement remains a challenging topic.

In practice, this means that eventually, you’ll run across an error notification, or the received measurement results are not as expected. When this happens, the most important step is to take a deep breath and orient yourself into problem-solving mode. The solution might be just around the corner, but hasty actions can lead you further away from it.

To start with, Qosium has some inbuilt intelligence for detecting incorrect parameterization. However, some parameterization errors are still not (yet) detected. For example, selecting wrong interfaces is something that Qosium does not recognize as an error. Thus, it helps a lot if you are well familiar with the use of Qosium, and, in general, the philosophy of passive measurements.

If something peculiar is happening in the measurement, start by considering the following:

  • What do I exactly want to measure?
  • Does Qosium even support my needs?
  • Have I built my measurement setup accordingly?
  • Have I parameterized Qosium accordingly?
  • Is it possible that the, in my opinion peculiar, results are, in fact, real?

Errors of measurement setup can often be detected by observing the measurement results. In particular, if the statistic Sent Info Not Found shows continuous non-zero values, it often is a sign of false parameterization. Also, duplicated packets can cause problems to the QoS calculation of Qosium. That is not necessarily related to false parameterization but to what you want to measure and how.

If it seems likely that Qosium is to blame, try first to disconnect the measurement controller and connect back. That reconstructs the whole measurement context and can help if something went wrong in the measurement process itself. Measurement controller restart can help in some rare cases, but Qosium Probe restart is hardly ever needed, but, of course, can be tried too. Reinstalling Qosium is not recommended since it can help only in some very rare license-related issues.

Try also studying both the log output of Scope and the console output of Probe. They can lead you to the source of the problem.

Next, we go through some common special situations. If you don’t find relief to your problem in this section, contact Kaitotek’s support.

2. Startup Problems #

2.1. Missing wpcap.dll (Windows) #

2.2. Qosium Probe Does Not Start #

2.3. License Activation Issue #

3. Common Special Situations #

3.1. Negative Delay Values #

3.2. QoS Results Disappear #

3.3. No QoS Results #

3.4. Giving Commands Results in Timeout #

3.5. Correct Packet Filter but No Packets #

3.6. Pcap Drops Packets #

3.7. Excessive Qosium Control Traffic #

3.8. New Interface Not Appearing #

3.9. Missing Interface #

3.10. Mouse Issue with GNSS in Windows #

4. Inconsistent Statistics #

4.1. The Statistic Sent Info Not Found Grows #

4.2. The Statistic Duplicate Packet Count Grows #

4.3. High Packet Losses #

Further Reading

Glossary >

Virtual LAN

A LAN seqment which has no physical hardware, but instead is carried over network.

Maximum Transmission Unitm

This determines the largest packet size that can be communicated in a single network-layer transaction.

Network Interface Card

A piece of hardware which offers a device a networking interface.