Basic NQA concepts
An NQA test group specifies test parameters including the test type, destination address, and destination
port. Each test group is uniquely identified by an administrator name and operation tag. You can
configure and schedule multiple NQA test groups to test different objects.
Test and probe
After the NQA test group starts, tests are performed at a specific interval. During each test, a specific
number of probe operations are performed. Both the test interval and the number of probe operations
per test are configurable. But only one probe operation is performed during one voice test.
In different test types, probe operation has the following different meanings:
During a TCP or DLSw test, one probe operation means setting up one connection.
During a UDP jitter or a voice test, one probe operation means continuously sending a specific
number of probe packets. The number of probe packets is configurable.
During an FTP, HTTP, DHCP, or DNS test, one probe operation means uploading or downloading
a file, obtaining a web page, obtaining an IP address through DHCP, or translating a domain
name to an IP address.
During an ICMP echo or UDP echo test, one probe operation means sending an ICMP echo request
or a UDP packet.
During an SNMP test, one probe operation means sending one SNMPv1 packet, one SNMPv2C
packet, and one SNMPv3 packet.
NQA client and server
A device with NQA test groups configured is an NQA client, and the NQA client initiates NQA tests. An
NQA server makes responses to probe packets destined to the specified destination address and port
Figure 5 Relationship between the NQA client and NQA server
Not all test types require the NQA server. Only the TCP, UDP echo, UDP jitter, or voice test requires both
the NQA client and server, as shown in
You can create multiple TCP or UDP listening services on the NQA server. Each listens to a specific
destination address and port number. Make sure the destination IP address and port number for a
listening service on the server are the same as those configured for the test group on the NQA client.
Each listening service must be unique on the NQA server.
NQA probe operation procedure
An NQA probe operation involves the following steps:
The NQA client constructs probe packets for the specified type of NQA test, and sends them to the
Upon receiving the probe packets, the peer sends back responses with timestamps.