Theoretical minimum round-trip-time for a packet to travel over/under the North Atlantic Sea?

capacity-planning, latency, networking, optimization

Solution

I believe the index of refraction of fiber is around 1.5, and the internet reports it's around 5600 km from NY to London, so the theoretical minimum one-way is `5600 km / (c/1.5) =~ 28 ms`. Round-trip is double that, 56 ms.

Up to you to do the real work of estimating latency through your routers and all.

P.S. The cables might not be straight :p

Edit: A bit of the wikipedia article on optical fiber pretty much contains all this information.

Problem

I'm doing some performance tuning and capacity planning for a low-latency application and have the following question: What is the theoretical minimum round-trip time for a packet sent between a host in London and one in New York connected via optical fiber?

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