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.

i_round_blueThe 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

QoS (Quality of Service) Round Trip Sensor

i_square_cyanFor 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: QoS (qualité de service) 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

Consider the following remarks and requirements for this sensor:

Remark

Description

Performance impact

This sensor has a high performance impact. We recommend that you use no more than 200 of this sensor on each probe.

Remote probe

This sensor requires that you configure at least one classic remote probe in your PRTG Network Monitor setup and at least two classic 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.

Cluster probe

This sensor does not support cluster probes. You can only set it up on local probes or remote probes.

IPv4

This sensor only supports IPv4.

Knowledge Base

Hosted probe

i_podYou cannot add this sensor to the hosted probe of a PRTG Hosted Monitor instance. If you want to use this sensor, add it to a remote probe device.

Basic Sensor Settings

Basic Sensor Settings

Basic Sensor Settings

The sensor has the following default tags that are automatically predefined in the sensor's settings when you add the sensor:

  • qossensor

i_square_cyanFor more information about basic sensor settings, see section Sensor Settings.

Quality of Service Measurement

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).

i_round_blueIf 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.

i_square_cyanFor more information about the QoS Reflector, see the Knowledge Base: How can I monitor QoS round trips without using remote probes?

Target Probe

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.

i_round_redYou must make sure that firewalls or network address translation (NAT) rules allow UDP packets to reach the target probe. The probe automatically opens the Windows firewall on the target system. For more information, see the Knowledge Base: What connection settings are necessary for the QoS (Quality of Service) Round Trip sensor?

i_podIn 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.

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.

i_round_redUse a different port for each QoS (Quality of Service) Round Trip sensor to make sure that PRTG can assign packets correctly.

i_round_redThe 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.

i_round_blueWe 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.

i_round_blueWe 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.

i_round_blueWe recommend that you use the default value.

Sensor Display

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, PRTG displays the last value of the primary channel below the sensor's name. The available options depend on what channels are available for this sensor.

i_round_blueYou can set a different primary channel later by clicking b_channel_primary below a channel gauge on the sensor's Overview tab.

Graph Type

Define how this sensor shows different channels:

  • 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.
    i_round_redYou 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. PRTG stacks all channels with this unit 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 b_inherited_enabled under the corresponding setting name to disable the inheritance and to display its options.

i_square_cyanFor more information, see section Inheritance of Settings.

Channel List

i_round_blueWhich 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

i_round_blueThis 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

i_round_blueThis channel has a default limit:

  • Upper warning limit: 100

Packets Corrupted

The corrupted packets (%)

i_round_blueThis channel has a default limit:

  • Upper warning limit: 0

Packets Duplicated

The duplicated packets (%)

i_round_blueThis channel has a default limit:

  • Upper warning limit: 0

Packets Lost

The lost packets (%)

i_round_blueThis channel has a default limit:

  • Upper warning limit: 1

Packets Out Of Order

The out of order packets (%)

i_round_blueThis 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

i_square_blueKNOWLEDGE BASE

How can I monitor QoS round trips without using remote probes?

How does PRTG calculate the MOS score for QoS sensors?

What connection settings are necessary for the QoS (Quality of Service) Round Trip sensor?

What security features does PRTG include?

 

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