Measurement Results in Qosium

Qosium has four types of results: Average, flow, packet, and pcap results.

1. Overview #

Qosium produces various statistics that can be evaluated in real-time, e.g., with Qosium Scope. The results can also be printed into files for later analysis. The results files are in CSV format, allowing easy import to external statistical tools (e.g., Excel, MATLAB, and R). During measurement, the results can be injected directly to separate results servers, such as Kaitotek’s Qosium Storage or any software that implements the QMCP Listener interface. Further, if you have implemented the QMCP Controlling interface, you can control Qosium measurements and gather all the results directly in your software.

2. Result Types #

Qosium can produce four types of results:

  • Average results - Average results are averaged over Averaging Interval, which is a parameter you can define. The average results constitute the most important statistic set with over 50 specific statistics to be evaluated.
  • Packet results - In a two-point measurement, Packet results give accurate QoS statistics for every single measured data packet. They are useful, e.g., in solving flickering QoS problems. In a single-point measurement, these results provide packet basic information.
  • Flow results - Flow results give a straightforward view of who is communicating with who, how, and how much traffic there is flowing. Flows consuming high bandwidth are easily detected.
  • Pcap results - These results provide you with full packet captures of desired traffic in the popular Pcap format, allowing you further to analyze the details with protocol analyzers such as Wireshark. This is an optional feature.

Most of the Qosium’s statistics are unidirectional, so they are available for received (downlink) and sent (uplink) directions.

The units of the statistics might be different in different tools (e.g., Scope vs. Scope Lite) and views (e.g., numeric view vs. graphs). There can also be some differences in the statistics’ names depending on where it is used (e.g., real-time visualization vs. results file).

3. Average Results #

3.1. General Statistics #

This category includes general measurement-level statistics that are informative rather than directly related to the networking performance.

Name Description Unit
Control Packet Number The number of the control packet (an increasing counter) Count
Measurement Duration The duration of the measurement. Seconds
True Averaging Period The true (accurate) averaging period length. Why is there such a value when one has particularly specified, e.g., 1 s averaging interval? In a non-real-time operating system, it is challenging to achieve highly accurate timings if not operating the program in a way that consumes a lot of processor resources. And, while this is not the way Qosium is built, then the true averaging interval will mostly have a slightly different value from the set one. Seconds
Timestamp The timestamp at the time when the current results were calculated. This value is taken at the Primary Probe. Unix epoch

3.2. Single-Point General Statistics #

This category includes single-point general statistics that are Probe-specific.

Name Description Unit
Malformed packets The number of packets whose internal structure is not correct. Packets
Malformed packets, total The number of packets whose internal structure is not correct (total, measurement) Packets
Drops, NIC The number of interface’s dropped packets during the measurement. Many Pcap versions (e.g., WinPcap) do not support this yet. This is calculated on the Primary Probe side only. Packets
Drops, NIC, total The same as above, but the total value over the measurement. Packets
Drops, Pcap The number of Pcap’s dropped packets. NOTE: If this starts to increase, it typically means that the Pcap driver is not able to capture the packets as fast as there is traffic, meaning typically that the computer is running out of resources. This is calculated on the Primary Probe side only. Packets
Drops, Pcap, total The same as above, but the total value over the measurement. Packets
Location: Accuracy Accuracy of the current location. Meters
Location: Altitude Altitude of the current location. Meters
Location: Duration from last update The age of the last location update. This parameter is handy in checking that the positioning is working correctly. Seconds
Location: Heading Heading at the current location if the node is moving. Degrees
Location: Latitude Latitude coordinate of the current location. Degrees [-90°, 90°]
Location: Longitude Longitude coordinate of the current location. Degrees [-180°, 180°]
Location: Mode Operation mode of the positioning (Qosium specific):
Location: Speed Speed of at the current location if the node is moving: Meters / s
Short packets The number of packets that are too short for analysis. Packets
Short packets, total The number of packets that are too short for analysis (total, measurement). Packets

3.3. Physical Layer Statistics #

This category includes single-point Probe-specific statistics related to the physical layer properties, typically radio interface, including signal performance, cell information, etc. The availability of these statistics is dependent on the platform where Qosium Probe is running.

Name Description Unit
Base Station MAC address The current Base Station MAC address. String
Cell ID The cell ID of the current wireless network (e.g., in LTE). Number
Network type The type of the network (e.g., LTE, WLAN, 5G). Coded value
SINR The signal to noise and interference ratio at the interface. dB
Signal (RSRP) The signal strength (Reference Signal Received Power) at the network interface. dBm
Signal (RSRQ) The signal quality (Reference Signal Received Quality) at the network interface. dBm
Signal (RSSI) The signal strength (Received Signal Strength Indication) at the network interface. dB

3.4. Traffic Statistics #

Traffic information that the single-point measurement can provide includes load, packet sizes, etc. These statistics are available from both primary and secondary Probe.

Name Description Unit
Duplicates The observed duplicate packets (based on the packet identification method). Packets
Duplicates, total The observed duplicate packets as above, but summed over the measurement. Packets
Packet size Average packet size during the last averaging interval. Note: The packet size means the total size at the link layer, so there is the link-layer header (Ethernet, etc.) also included. Bytes
Protocol Dominating protocol number in the measured stream. Protocol number
Traffic, bits/s The traffic load in bits/s (offered load and throughput). Bits / s
Traffic, bytes The amount of transmitted/received data. Bytes
Traffic, bytes, total The amount of transmitted/received data summed over the measurement. Bytes
Traffic, packets The amount of transmitted/received packets. Packets
Traffic, packets, total The amount of transmitted/received packets summed over the measurement. Packets
Traffic, packets/s The traffic load calculated in pkts/s (offered load and throughput). Packets / s

3.5. QoS Statistics #

QoS statistics are mostly two-point statistics that are calculated for a flow over a network path. They describe the flow’s behavior over the network path and include important statistics like delay, packet loss, etc. Some of the QoS statistics can also be calculated in a single-point measurement for a restricted set of protocols (e.g., RTP and MPEG-2 TS).

All the QoS statistics Qosium produces are one-way statistics between the measurement points.
These statistics are available in a two-point measurement only.

Name Description Unit
Connection break count The number of connection breaks during the last averaging interval. Count
Connection break duration Connection break duration (time-domain) Seconds
Connection break length Connection break length (packet domain), often as mean loss burst size. Packets
Connection break length, total As previous, but averaged over the whole measurement. Packets
Connection break maximum duration The maximum connection break duration in the last averaging interval. Seconds
Delay Delay – one-way – as all the QoS statistics. Seconds
Delay threshold crossings The number of packets whose delay exceeded the set threshold. Packets
Delay threshold crossings, total The number of packets whose delay exceeded the set threshold (total, measurement). Packets
Delay, max The maximum observed sample delay during the last averaging interval Seconds
Delay, min The minimum observed sample delay during the last averaging interval Seconds
Delay samples The number of Delay samples, i.e., how many values have been used to calculate the QoS statistics Samples
Jitter The pure delay variation Seconds
Jitter threshold crossings The number of packets whose jitter exceeded the set threshold Packets
Jitter threshold crossings, total The number of packets whose jitter exceeded the set threshold (total, measurement) Packets
Jitter, max The maximum observed sample jitter during the last averaging interval Seconds
Jitter, MA Moving average jitter (similar as in RTP) Seconds
Lost Packets The number of lost packets included in the QoS calculation Packets
Lost Packets, total The number of lost packets included in the QoS calculation (total, measurement) Packets
Packet loss Packet ratio of packets which were lost in the measured network path. Percentage
Packet loss, total Packet loss ratio (total, measurement) Percentage
QoS samples The number of packets that were used to calculate the QoS statistics. Packets
Sent info not found This special statistic is, in a way negative packet loss, meaning that a packet was received but was not indicated as sent in the other end. As understood, this is not a normal situation, and it is often a sign of false-parameterization if you see continuously non-zero values here. Still, this can happen in extreme cases where the QMCP connection between Qosium Probe’s is suffering from terrible network quality. If the network somehow alters the packet stream between the measurement points, you will see non-zero values here. As a result, this statistic should be observed as an indicator of something weird that should be investigated. Packets
Sent info not found, total The summed value of the previous over the measurement. Packets
Successful packets The number of successfully transmitted packets included in the QoS calculation Packets
Successful packets, total The number of successfully transmitted packets included in the QoS calculation (total, measurement) Packets

3.6. QoE Statistics #

This category includes higher-level statistics refined typically from the QoS statistics. The Quality of Experience (QoE) is closer to the user’s observations than the pure QoS. These statistics are available only for certain applications.

While QoE refers to real user tests, the QoE statistics provided here are QoE approximations based on the measured QoS metrics and correlation with measurement data gathered with real user tests.
Name Description Unit
GQoSM QoE evaluation by using GQoSM algorithm MOS (1-5)
PSQA QoE evaluation by using PSQA algorithm MOS (1-5)

4. Packet Results #

4.1. Packet Statistics #

These are single-point statistics, giving general information on captured packets. Why not always evaluate full Pcap traces instead, since Qosium also provides them? First, taking Pcap traces from a remote point generates a control load roughly equal to the amount of measured traffic. Getting Qosium’s Packet statistics generates only a fraction of that. The same goes for the required storage space as well. Second, Qosium can be used in sensitive environments, where full packet capturing is not even allowed. In many cases, the general packet information is enough, and full captures are taken only when really needed.

Name Description Unit
Timestamp The packet capture time Microseconds
Direction Indicates whether the packet received or sent from the perspective of the measurement point.
Source Address The source address (Ethernet, IPv4, and IPv6 addresses currently supported) of the packet String
Destination Address The destination address (Ethernet, IPv4, and IPv6 addresses currently supported) of the packet String
Source Port The source port at the transport layer, when available
Destination Port The destination port at the transport layer, when available
ID The Identification number of the packet given by the chosen method
Protocol This indicates the protocol number above the network layer. If the network layer is absent, this indicates the protocol number above the link layer. Standard protocol numbering is used added with some of Qosium’s own definitions. Protocol number
Fragment offset The fragment offset of the packet, when fragmented at the IPv4 network layer 8-byte blocks
Size The total size of the packet Bytes

4.2. Packet QoS Statistics #

Name Description Unit
Timestamp The packet capture time at the sending end Microseconds
Direction Indicates whether the packet received or sent from the perspective of the primary measurement point.
Source Address The source address (Ethernet, IPv4, and IPv6 addresses currently supported) of the packet String
Destination Address The destination address (Ethernet, IPv4, and IPv6 addresses currently supported) of the packet String
Source Port The source port at the transport layer, when available
Destination Port The destination port at the transport layer, when available
ID The Identification number of the packet given by the chosen method
Protocol This indicates the protocol number above the network layer. If the network layer is absent, this indicates the protocol number above the link layer. Standard protocol numbering is used added with some of Qosium’s own definitions. Protocol number
Fragment offset The fragment offset of the packet, when fragmented at the IPv4 network layer 8-byte blocks
Size The total size of the packet Bytes
Delay The duration of time it took the packet to traverse from one measurement point to another. Microseconds
Jitter The absolute delay variation between consecutive packets Microseconds
Jitter (MA) Packet’s delay variation calculated as moving average (similarly as in RTP) Microseconds
Delivery information Indicates whether the packet was delivered correctly, lost, etc. This information might not be directly available in all visualization tools, but it is present, e.g., in the packet QoS results file.

5. Flow Results #

The flow results present captured traffic as conversations between source and destination hosts. What constitutes a conversation is determined by 3 - 5 identifiers:

  • Source address (and port, when available)
  • Destination address (and port, when available)
  • Protocol

When a packet is captured, these identifiers are compared to each existing flow’s identifiers. If none of the flows in the current flow results have the exact same identifiers, then a new flow is created instead. If no packets are detected in the given flow for the duration of the Flow timeout parameter, then Qosium determines that the flow has ended and it is removed.

Name Description Unit
Source address The source address (Ethernet, IPv4, and IPv6 addresses currently supported) string;
Source port The source port (transport layer). 0 is used if the transport layer does not have ports string;
Destination address The destination address (Ethernet, IPv4, and IPv6 addresses currently supported) Number;
Destination port The destination port (transport layer). 0 is used if the transport layer does not have ports Number;
Protocol This indicates the protocol number above the network layer. If the network layer is absent, this indicates the protocol number above the link layer. Standard protocol numbering is used added with some of Qosium’s own definitions. Protocol number
Flow start time The time when the flow was first registered. Microseconds
Flow end time The time when the flow was terminated. In results files, N/A is used if the flow had not ended at the end of the measurement. Microseconds
Flow age The age of the flow. Seconds
Sent traffic The amount of sent traffic, reported in different ways in different places. For example, Qosium Scope reports this in real time as bits/s, but in results files, this is the total amount of data (bytes). Bytes
Received traffic The same as previous but for received direction Bytes
Inactivity Indicates the duration, how long the flow has been idle (no packets detected). Seconds

6. Pcap Results #

Qosium can capture and save full packet captures as Pcap files. While Qosium itself doesn’t have a way to view these files’ contents, they can be opened with any packet analyzer tool that supports a well-known Pcap file format. For more information, see How to Take Packet Capture?.