Network latency and speed of light
- by James
This was kinda of covered by the following Is minimum latency fixed by the speed of light? , but i would like to add the follow up a bit.
The scenario is as follows; we have two opposing sites one on the West Coast of the US and one in Ireland. The customer is in central Europe, and has requested a latency test. Ireland gives responses of ~65-70ms. However the West Coast guys claim to be faster with a response of 60ms.
Now a quick check says that light in fiber would take about 42ms to make the trip to the States and 8.5ms to Ireland. So obviously this is a single hop and does not include routers, switches, firewalls, protocol overhead etc.
Would I be right to call BS on their figures?
As a final note I tested a ping to Google IP address that was allegedly on the west coast from a site that covered a similar distance and was amazed to get a response time of 20ms. Suggesting ICMP packets that travel twice the speed of light.
So A) what am I missing B) Am I right to suspect shenanigans?
UPDATE: Guys thanks so far for your help and I have been reading various previous questions on this. About 5 years I had an issue where the hop from the UK to Ireland added 10ms of latency no matter what we did. In the end I moved the servers; So imagine my surprise when I have guys that claim they are 5ms faster with a transatlantic trip.
So again should I call BS? Oh and assume both sites are normal mortals that don't have access to Google magical routing, warp dives or flux capacitors. :)
