why such variations in the testing for NQA and ping results on s6720

Hello guys, I got a quesiont when testing the NQA and the ping result.

Below is sample configuration‍‍

[HQ-6720]dis cu

#

nqa test-instance 1065635Mumdc_to_Ashok_Andheri_TCL

test-type icmp

destination-address ipv4 192.168.1.5

source-address ipv4 192.168.1.6

frequency 300

probe-count 15

datasize 56

start now

#

return

‍‍‍‍We have configured NQA for some the major links. But as checked there is lot of variations in the latency for results of NQA.‍‍

Please find below Screen Shot captured.

<HQ-6720>display nqa historytest-instance 1065635 Mumdc_to_Ashok_Andheri_TCL

NQA entry(1065635,Mumdc_to_Ashok_Andheri_TCL) history:

IndexT/H/P       ResponseStatus      Address         Time

46  36183/1/1       20mssuccess      192.168.1.5     2019-06-28 11:37.326

47  36183/1/2       21mssuccess      192.168.1.5     2019-06-28 11:37.326

48  36183/1/3       19mssuccess      192.168.1.5     2019-06-28 11:37.326

49  36183/1/4       19mssuccess      192.168.1.5     2019-06-28 11:37.386

50  36183/1/5       29mssuccess      192.168.1.5     2019-06-28 11:37.386

‍‍Above showing as the latecy value to be 29 ms. But actually checked the latency by ping is much less.

<HQ-6720> ping -c 15 -a192.168.1.6 192.168.1.5

  PING 192.168.1.5: 56  databytes, press CTRL_C to break

    Reply from192.168.1.5: bytes=56 Sequence=1 ttl=64 time=2 ms

    Reply from192.168.1.5: bytes=56 Sequence=2 ttl=64 time=2 ms

    Reply from192.168.1.5: bytes=56 Sequence=3 ttl=64 time=2 ms

    Reply from192.168.1.5: bytes=56 Sequence=4 ttl=64 time=6 ms

    Reply from192.168.1.5: bytes=56 Sequence=5 ttl=64 time=2 ms

    Reply from192.168.1.5: bytes=56 Sequence=6 ttl=64 time=2 ms

    Reply from192.168.1.5: bytes=56 Sequence=7 ttl=64 time=2 ms

  --- 192.168.1.5 ping statistics---

    7 packet(s)transmitted

    7 packet(s) received

    0.00% packet loss

    round-tripmin/avg/max = 2/2/6 ms

Please confirm why such variations in results are being shown.