First, check the bandwidth which is the amount of data one can pass thru the line under the best conditions using large packets. It is measured in bits per second. Go to http://www.speedtest.net pick a city near you and run the test. If I get a crazy answer I Google some other “speed test”. The crazy (high) answers sometimes come from the browser caching the test data. My FIOS connection from Verizon is 30 Mb (Megabit) download and 30 Mb upload. Note: Each major update of your browser (Chrome, Internet Explorer/Edge, Safari, etc.) seems to tweak how they cache data. These changes often screw up download bandwidth tests. If you get a very high download bandwidth number try some other test. Over time the providers of these tests update them to work correctly.
Next check for packet loss which is the percentage of TCP/IP packets that have to be resent due to errors, and jitter which is how consistent the line is.
Latency is how long it takes for a packet to make a round trip to another computer. It is limited by the physical distance and the speed of light. It takes longer for me to round-trip at packet to London than Los Angeles from Seattle. If you bring up a Command window or a MS-DOS window and type “ping www.whichvoip.com” you should see something like Reply from 18.104.22.168: icmp_seq=6 ttl=50 time=70.898 ms, In this case, the latency was 70 milliseconds for me. WhichVOIP is located in Los Angeles. If I were to a site in England I would see something like 160 ms. This will give you a range of reasonable numbers. Note that your bandwidth has very little to do with this number since you are only sending 64 bytes. A dial-up line would get very similar numbers. However, cell phones have VERY HIGH latency – often in the 300 to 400 ms range.
If you want to know where a domain, site or IP address is located use UTrace to do this and you will find the city. Note that this is the location of your ISP’s connection to the internet. I am located in Woodinville WA, but since Frontier’s nearest central office is in Bothell, WA that is what is shown.