Usage Scenario
An NQA test consists of multiple
probes. By default, if one or more probes are successful in an NQA
test, the test is considered a success. If all probes fail, the test
is considered a failure. The number of probes in an NQA test is based
on the network quality.
- If the network to be tested is a reliable network, the number
of probes can be set relatively small because the probe can be successful
after a small number of probe packets are sent.
- If the network to be tested is an unreliable network, the number
of probes can be set relatively large because the probe can be successful
only after a large number of probe packets are sent.
You can also detect the network quality based on statistics
obtained from multiple probes. For example,
- If the probe test is successful after a small number of probes
packets are sent, the network quality is good.
- If the probe test is successful after a large number of probes
packets are sent, the network quality is poor.
Before running the
probe-count command,
run the
test-type command to specify the type of a test instance, which may
be one of the following:
- ICMP
- DHCP
- HTTP
- UDP-tracert
- TCP
- UDP
- UDP-jitter
Configuration Impact
The functions of probe-count vary with different test types.
- ICMP and UDP tests: A probe packet is sent during one probe operation.
The probe-count command specifies the number of
packets to be sent in a test.
- DHCP and HTTP tests: A probe operation completes one corresponding
function. For example, applying for an IP address from the DHCP server
or requesting for accessing a web page of the HTTP server. The probe-count command is used to set the number of IP address
applications sent to the DHCP server or the number of requests for
accessing a web page sent to the HTTP server.
- UDP-tracert tests: A complete Tracert process implemented on a
destination node is known as a Tracert test, and an operation for
sending a probe packet with a specific TTL value is known as a probe
operation. The number of the sent probe packets with the specific
TTL value is specified by using the probe-count command.
- UDP-jitter tests: Multiple probe packets are sent during one probe
operation. The probe-count specifies the number
of probe operations. The number of probe packets sent during a single
probe operation is specified by using the jitter-packetnum command.
Precautions
The number of probes of a running
test instance cannot be changed.