Manual Measurements

Using Qosium is typically either manual measuring or automatic monitoring. Measuring can be, for example, field tests for wireless network performance, troubleshooting network problems, or benchmarking a device or a service in laboratory conditions.

Toolbox

The selection of Qosium-components is based on the need. When performing manual measurements, you typically need only Qosium Scope in addition to the always-present measurement agents, Qosium Probes. Qosium Scope is a real-time analyzer for managing Qosium measurements. You can use Scope to activate and control Qosium Probes over a network connection. The essential features of Scope are measurement parameterization, running measurements, results collection, and results visualization. Qosium Scope is an excellent tool for manual QoS and QoE measurements. In limited environments, you can use Qosium Scope Lite. The measurements can be carried out anywhere without an Internet connection.

In more comprehensive measurement setups, it might be helpful to use a separate results system like Qosium Storage, but it is typically only needed when executing automatic monitoring.

As Qosium is a passive measurement system, the measurement target often is real service/application traffic. Sometimes, however, it might be necessary to use artificial traffic streams in measurement campaigns. In these cases, Qosium can be used semi-actively: the traffic to be measured is actively generated with an external traffic generator, while Qosium is used passively to measure its QoS over the interesting network path. Qosium’s measurement is accurate, which is not the case with many traffic generators.

Measurement Scenarios

The placement of Qosium Probes defines the basis for the measurement. QoS measurement is targeted in the network path between the Probes. You can also measure in a single point, but the available results will be considerably limited.

The example below presents one of the most straightforward measurement scenarios. Qosium Probes are installed in the communicating end devices, so the setup is an end-to-end measurement. This setup yields accurate QoS statistics on how the measured application experiences the whole network path. The measured traffic can range from a single flow to all the traffic between the measurement points.

Qosium Probe takes care of almost all of the measurement-related calculations. As a passive agent, Qosium Probe needs to sit on nodes from which measurement results are wanted to be collected, i.e., the measurement points. Qosium Probe is typically being run as a system service hidden in the background. The visible part of the measurement is Qosium Scope, which you use to control the measurement. It can lie on the same device as Qosium Probe or elsewhere.

The measurement setup can also be more complex. Instead of a single measurement, there can be multiple ongoing measurements at different network parts. In addition, the setup does not need to be end-to-end, but the measurement can be targeted to a specific part of the network, like, for instance, the wireless access part. A single Probe can handle multiple simultaneous measurements, so you only need one Probe per device.

Qosium needs no support from the measured traffic: it can be any IPv4 or IPv6-based or even pure Ethernet traffic. No requirements are set for the network either. Instead, the links between the network nodes can be of any wired or wireless technology.

Qosium Probe can be installed on almost all desktop and server machines, lightweight end devices, and many embedded devices. We continuously extend Qosium to new platforms and operating systems according to demand.

The document section talks more about Qosium Probe.

Measurement Control

The measurements are managed by using Qosium Scope. It is a comprehensive analyzer software for manual measurements. With Scope, all features of Qosium measurements are at your fingertips.

Qosium Scope comes with an extensive set of parameters to configure measurements. However, parameterizing a typical measurement is straightforward. It’s only a few settings you need to touch in most cases. All the parameters and visualization settings can be, naturally, saved, making it easy to return to an earlier measurement.

Qosium Probes come with a registration feature, which helps identify devices available for measurements. Use Qosium Scope to get a list of the available measurement points in the network. You can connect the desired Probes from the list for the upcoming measurement. The list also reveals coarse network problems when Probes are missing. However, this feature is perhaps, the most useful when the IP addresses of network devices are dynamic. With the unique identifier, a network node can be identified despite the changing IP address.

Result Analysis

By using Qosium Scope, the measurement results are typically analyzed in real-time, but it also allows post-analysis of earlier results. Measurement results can be visualized in multiple ways. Meters, graphs, bars, and numerical formats, it’s up to you how you want to take a look at results and which results. Visualized results are averaged over the desired time period. From average results, you can drill into packet results where QoS results for every single packet are shown. Because all the Qosium components share the same results format, you can use Qosium Scope to study results recorded by other measurement controllers (Qosium Scopemon and Qosium Scope Lite) and analyze also results downloaded from Qosium Storage.

Graphs let you see how results have developed over time. Meters, on the other hand, allow you to see the current situation. Results like delay, jitter, traffic load, packet loss, and over 20 other measures are measured and visualized always to both directions. In all the visualization options, it is easy to select what statistics you want to show.

Changing between different visualization types and creating your dashboard views is easy. You can select the measures for visualization freely and name the dashboards as you wish.

QoS heatmap is perhaps the most elegant feature of Qosium Scope. If Qosium Probe has location information during a measurement, Qosium Scope allows visualizing any measure (for example, delay) on a map, even in real-time. Qosium Scope makes it possible to find out the coverage area of a wireless network, not in terms of signal strength but in terms of the actual quality experienced by end-users. This is especially useful in drive tests.

It is possible to also bring your own overlay images to Qosium Scope’s map. The image can be, for example, a building layout for indoor wireless measurements. Satellite positioning doesn’t work well indoors, but location information can also be given by clicking a mouse or by using some other positioning technique.

Heatmap visualization can be parameterized to satisfy your needs. This includes, for example, ruling color coding, defining drawing precision, and selecting map style.

In addition to QoS results, Qosium Probes extract overall network traffic to traffic flows. Flow analysis in Qosium Scope shows which network devices talk with whom through the node Qosium Probe is running. It is also a simple way to recognize if interesting or even suspicious applications are traversing the Probe node.

The document section talks more about Qosium Scope.

Storing Results

All measurement results can be saved to files, which can later be loaded back to Scope. The results are in CSVComma-Separated Values
Originally CSV was only about values that were separated by commas, but nowadays the separation mark can also be something else like a semicolon. format, enabling them to be taken easily to other analysis tools. The results can also be sent to an external results system, such as Qosium Storage, in real-time when available in the measurement setup.

Qosium can also take packet captures from the traffic being measured. This is an optional feature, which can be left out entirely from a build if desired. A Pcap file is generated, which can be taken, for example, to Wireshark for accurate protocol analysis. Packet capture is taken at layer-2, ensuring that MAC layer protocol headers are also included.