1-11 
Delay jitter refers to the difference between the interval of receiving two packets consecutively and the 
interval of sending these two packets. The procedure of a UDP jitter test is as follows: 
z  The source sends packets at regular intervals to the destination port. 
z  The destination affixes a time stamp to each packet that it receives and then sends it back to the 
source. 
z  Upon receiving the packet, the source calculates the delay jitter, and the network status can be 
analyzed. 
Configuration prerequisites 
A UDP jitter test requires cooperation between the NQA server and the NQA client. Before the UDP jitter 
test, make sure that the UDP listening function is configured on the NQA server. For the configuration of 
the UDP listening function, see 
Configuring the NQA Server. 
Configuring a UDP jitter test 
Follow these steps to configure a UDP jitter test: 
To do…  Use the command…  Remarks 
Enter system view 
system-view
 
—
 
Enter NQA test group view 
nqa entry admin-name 
operation-tag 
—
 
Configure the test type as UDP 
jitter and enter test type view 
type udp-jitter 
Required 
Configure the destination 
address for a test operation 
destination ip ip-address 
Required 
By default, no destination IP 
address is configured for a test 
operation. 
The destination IP address 
must be consistent with that of 
the existing listening service on 
the NQA server. 
Configure the destination port 
for a test operation 
destination port port-number 
Required 
By default, no destination port 
number is configured for a test 
operation. 
The destination port must be 
consistent with that of the 
existing listening service on the 
NQA server. 
Specify the source port number 
for a request 
source port port-number 
Optional 
By default, no source port 
number is specified. 
Configure the size of a probe 
packet sent 
data-size size 
Optional 
100 bytes by default. 
Configure the filler string of a 
probe packet sent 
data-fill string
 
Optional 
By default, the filler string of a 
probe packet is the 
hexadecimal number 
00010203040506070809.