In very simple words, the number of routers through which a packet passes on its way from source to destination is called hop count.
Ping utility can be used to measure the RTT. Ping generates a sequence of request-responses and measures the RTT. Traceroute utility can be used to measure the hop count.
Following observations were made by me regarding RTT and hop count to the given web servers:
Web Server RTT Hop Count
www.columbia.edu 383 ms 20
www.qualcomm.com 36.500 ms 6
Commands used : ping <webserver>, traceroute <webserver>.
for ex. traceroute www.qualcomm.com
You can try this multiple times at different times of day as mentioned in the given question.
Generally, the RTT values increase with the increasing hop cont. Sometimes, different routes have different relationships between these two measures. Geographically far hops contribute far more propagation delay than the near ones.
