How Orion calculate response time with SNMP & ICMP ?
Once the Status & Response Time will be selected SNMP Orion will start monitoring the device by sending request to following object OID 126.96.36.199.188.8.131.52.0.
Request packet is been sent by regular interval and each get request will be waiting for get response from the device .
Once the get-response packet will be received the ms time will be calculated between the get-request & get-response in order to generate and calculate the "Response Time" from the Node .
See the Wireshark screen below .
SNMP get-request packet
SNMP get-response packet
Once the ICMP (Ping) - Fastest response the simple ICMP packet is been sent through Orion Engine and will calculate the actual Response time been sent within the packet.
See the Wireshark screen below . (ICMP Request packet & Reply with Response Time )
Please Note : You will notice high Response Time values compared with ICMP when monitoring through SNMP this is normal behavior as the device has to process the SNMP request through SNMP Engine and depends how busy it is at that time .