Device Queue is the starting point within a Canvas, which is generated automatically when you create the Canvas node. It is essentially a table that stores the devices waiting for execution by a Qapp. The devices obtained by a Qapp and filtered via Filter Criteria will be passed to Device Queue at runtime. Therefore, whether a device can be loaded to the Device Queue node depends on the way that you set a Qapp to obtain devices at the Start node as well as the conditions that you have defined in the Filter Criteria.

A Qapp loops Device Queue row by row from top to bottom, and at each loop cycle, it reads devices in one row to retrieve data, analyze data and present analysis results. The Qapp will repeat the loop process until finishing all rows.

At this node, you can define the pattern to load input devices to the Device Queue:

Deviceloads devices in a single device pattern and each device is an independent individual in the Device Queue.

Neighbor Pairloads devices in pairs and each pair is a pair of neighbor devices. This Device Queue pattern is often used to compare the difference of a device and its neighbor, such as MTU and Duplex mismatch.

Pathloads devices in hop pattern. Each hop contains a device, the incoming interface and outgoing interface. If you select the Calculated Path option at the Start node, the Path option here is selected by default.

Tableload devices from a specified table and the pattern to build devices depends on the definition of the imported table. If you select the Table option at the Start node, the Table option here is selected by default. The specific table you can select is defined in the Global Table.


Defining a Device Queue Node

1.Click the Device Queue node on the Canvas tab.

2.Select the device input from the Device Input drop-down list. There are four options as follows:

Neighbor Pair

3.Extend the next node for the Device Queue node based on your needs. For how to extend nodes, see Extending a node for details.


Device (such as this, nbr, prev, and next, which can be extended depends on the settings you selected in step 2).


Next nodes: