I'm wondering if some clueful poeple here can help me.
I've been looking at a few traceroutes from NZ to various overseas destinations and what been bugging me is the times involved with the undersea cable legs.
For example round-trip tracing from Auckland to Sydney (host905.rimuhosting.com)
5. vocus1.ape.nzix.net 3.4
6. ten-0-2-0-400.bdr01.akl01.akl.VOCUS.net.au 43.1
So the real-world one-way distance would be 19.85ms
According to wolfram|alpha "distance auckland sydney" is 10.1ms
According to Southern Cross Networks themselves the auckland sydney cable leg is 11.38ms.
So 19.85 real world, 11.38 for the distance. We have a missing 8.47ms which is huge!
Can anyone explain why? Don't tell me its routers because i'm measuring the between two routers in a path.
Maybe network equipment we can't see? In this trace its within the Vocus network before it heads across the sea and stays within the Vocus network for a good number of hops after so not likely that its bad network design (ie surely all things within their control).
I should add that this is true for Auckland->US etc, and the above trace is not a problem but an example of a generalisation of why Auckland-Sydney (or any other place) seems twice as far away as it should be.