Understanding NQA

Constructing a test instance

NQA requires two test ends: an NQA client and an NQA server (also called the source and destination, respectively). The NQA client initiates NQA tests, which you can configure through the command line or the network management system (NMS). NQA then places the test instances into test queues for scheduling.

Starting a test instance

The user can choose to start an NQA test instance immediately, at a specified time, or after a delay. The test instance waits the specified amount of time and then generates a test packet in accordance with the test type. If the size of the test packet is smaller than the minimum size required by the protocol, the test packet is padded to the minimum size.

Processing a test instance

In an NQA test instance, the operating status of the protocol is determined based on the response packets. The client adds a timestamp to the test packet according to the local system time before sending the packet to the server. After receiving the test packet, the server sends a response packet to the client. The client receives the response packet and again adds a timestamp according to the current local system time. The client then calculates the round-trip time (RTT) of the test packet based on the two timestamps.

In a jitter test instance, both the client and server add a timestamp to the sent and received packets according to the local system time. This allows the client to calculate the jitter.

You can view the test results to learn about the operating status and service quality of the network.