Device Response Time Questions

hi, if I open up a device it comes up with the today's availability, device response time and today's packet loss amongst other stuff. I want to know what protocol the device response time is being measured on (icmp?) and if it is icmp can the packet size be controlled. There also doesn't seem to be any report based on this counter - there are response time by service reports and response time by service also appears on the home tab but no response time by icmp(?) in report form of on the home tab.

so in summary - 1) what protocol is used for device response time and can the packet size and number of packets be controlled; and 2) is there a report of screen that shows slowest devices based on the device response time.

thanks, Lerwick