PRTG Manual: QoS (Quality of Service) Round Trip Sensor
<%NUMBERING1%>.<%NUMBERING2%>.<%NUMBERING3%> PRTG Manual: QoS (Quality of Service) Round Trip Sensor
The QoS (Quality of Service) Round Trip sensor monitors parameters regarding the quality of a network connection between two probes.
The sensor sends a series of User Datagram Protocol (UDP) packets from the source probe to a target probe at the end of the connection line. Then, the target probe sends the packets back to the source probe.
QoS (Quality of Service) Round Trip Sensor
For a detailed list and descriptions of the channels that this sensor can show, see section Channel List.
Sensor in Other Languages
Dutch: QoS (Quality of Service) Heen en weer
French: Quality of Service (QoS) aller-retour
German: QoS (Quality of Service) Round Trip
Japanese: ラウンドトリップ QoS(Quality of Service)
Portuguese: Ida e volta QoS (qualidade de serviço)
Russian: Цикл тестирования качества обслуживания
Simplified Chinese: QoS (服务质量) 往返
Spanish: Ida y vuelta QoS (calidad de servicio)
Remarks
This sensor has a high performance impact. We recommend that you use no more than 200 of this sensor on each probe.
This sensor requires that you configure at least one remote probe in your PRTG Network Monitor setup and at least two remote probes in PRTG Hosted Monitor, or you must set up the PRTG QoS Reflector tool on the target system at the endpoint of the connection that you want to monitor.
This sensor does not support cluster probes. You can only set it up on local probes or remote probes.
If the name contains angle brackets (<>), PRTG replaces them with braces ({}) for security reasons. For more information, see the Knowledge Base: What security features does PRTG include?
This setting is for your information only. You cannot change it.
Tags
Enter one or more tags. Confirm each tag with the Spacebar key, a comma, or the Enter key. You can use tags to group objects and use tag-filtered views later on. Tags are not case-sensitive. Tags are automatically inherited.
It is not possible to enter tags with a leading plus (+) or minus (-) sign, nor tags with parentheses (()) or angle brackets (<>).
For performance reasons, it can take some minutes until you can filter for new tags that you added.
The sensor has the following default tags that are automatically predefined in the sensor's settings when you add the sensor:
qossensor
Priority
Select a priority for the sensor. This setting determines the position of the sensor in lists. The highest priority is at the top of a list. Choose from the lowest priority () to the highest priority ().
Quality of Service Measurement
Quality of Service Measurement
Setting
Description
Timeout (Sec.)
Enter a timeout in seconds for the request. Enter an integer. The maximum timeout value is 900 seconds (15 minutes).
If the reply takes longer than this value, the sensor cancels the request and shows a corresponding error message.
QoS Target
Define the type of target that receives the UDP packets:
Probe (default): Use a probe as the connection endpoint.
Custom target: Use the PRTG QoS Reflector as the connection endpoint.
This setting is only visible if you select Probe (default) above.
Define the target probe that receives the UDP packets. The dropdown list shows all local probes and remote probes in your setup.
If you want to run the sensor on the local probe, select a remote probe as the Target Probe. If no remote probe is available, install and connect a remote probe first. Alternatively, you can use the PRTG QoS Reflector.
If you want to run the sensor on a remote probe, select either a different remote probe or the local probe as the target. The sensor measures values for the network track between the parent probe and the target probe.
In PRTG Hosted Monitor, you can only select a different remote probe as the target probe. QoS measurements for connections to the hosted probe are not possible.
Target Host/IP Address
Define the IP address of the QoS target:
If you use the QoS Reflector, enter the address of the system on which the reflector script runs.
If you use a probe, enter the address of the probe to which the source probe connects.
If you do not use NAT rules, this is usually the IP address in parentheses next to the probe name under Target Probe.
Port
Define the source and target port for the UDP packets. Both the source probe and the target probe use this port. Enter an integer. The default port is 50000. PRTG supports the port numbers 1024-65536 for UDP packets.
Use a different port for each QoS (Quality of Service) Round Trip sensor to make sure that packets can be assigned correctly.
The port must be available on both the source system and the target system.
Number of Packets
Define the number of packets that the sensor sends with each scanning interval. Enter an integer. The default value is 1000. The minimum value is 10. The maximum value is 1000.
We recommend that you use the default value.
Packet Size (Bytes)
Define the size of the packets in bytes that the sensor sends. Enter an integer. The default value is 172. The minimum value is 172. The maximum value is 4500.
We recommend that you use the default value.
Packet Delay (ms)
Define the time in milliseconds (ms) that the sensor waits between two packets. Enter an integer. The default value is 20. The minimum value is 10. The maximum value is 1000.
We recommend that you use the default value.
Sensor Display
Sensor Display
Setting
Description
Primary Channel
Select a channel from the list to define it as the primary channel. In the device tree, the last value of the primary channel is always displayed below the sensor's name. The available options depend on what channels are available for this sensor.
You can set a different primary channel later by clicking below a channel gauge on the sensor's Overview tab.
Graph Type
Define how different channels are shown for this sensor:
Show channels independently (default): Show a graph for each channel.
Stack channels on top of each other: Stack channels on top of each other to create a multi-channel graph. This generates a graph that visualizes the different components of your total traffic. You cannot use this option in combination with manual Vertical Axis Scaling (available in the channel settings).
Stack Unit
This setting is only visible if you select Stack channels on top of each other above.
Select a unit from the list. All channels with this unit are stacked on top of each other. By default, you cannot exclude single channels from stacking if they use the selected unit. However, there is an advanced procedure to do so.
Inherited Settings
By default, all of these settings are inherited from objects that are higher in the hierarchy. We recommend that you change them centrally in the root group settings if necessary. To change a setting for this object only, click under the corresponding setting name to disable the inheritance and to display its options.
For more information, see section Root Group Settings, section Scanning Interval.
Schedules, Dependencies, and Maintenance Window
You cannot interrupt the inheritance for schedules, dependencies, and maintenance windows. The corresponding settings from the parent objects are always active. However, you can define additional schedules, dependencies, and maintenance windows. They are active at the same time as the parent objects' settings.
Schedules, Dependencies, and Maintenance Window
For more information, see section Root Group Settings, section Schedules, Dependencies, and Maintenance Window.
Access Rights
Access Rights
For more information, see section Root Group Settings, section Access Rights.
Channel List
Which channels the sensor actually shows might depend on the target device, the available components, and the sensor setup.
Channel
Description
Downtime
In the channel table on the Overview tab, this channel never shows any values. PRTG uses this channel in graphs and reports to show the amount of time in which the sensor was in the Down status
Jitter Average
The average jitter
Jitter Max
The maximum jitter
This channel is the primary channel by default.
Jitter Min
The minimum jitter
MOS
The MOS
Packet Delay Variation Average
The average packet delay variation
Packet Delay Variation Max
The maximum packet delay variation
Packet Delay Variation Min
The minimum packet delay variation
This channel has a default limit
Upper warning limit: 100
Packets Corrupted
The corrupted packets (%)
This channel has a default limit
Upper warning limit: 0
Packets Duplicated
The duplicated packets (%)
This channel has a default limit
Upper warning limit: 0
Packets Lost
The lost packets (%)
This channel has a default limit
Upper warning limit: 1
Packets Out Of Order
The out of order packets (%)
This channel has a default limit
Upper warning limit: 0
RTT (Average)
The average RTT
RTT (Maximum)
The maximum RTT
RTT (Minimum)
The minimum RTT
More
KNOWLEDGE BASE
How can I monitor QoS round trips without using remote probes?