8ms latency to India.
We had outsourced some our development to India and set up a VPN to their office. As I had experience of doing this at other companies, I explained to the development manager that trying to sync software repositories "over the wire" would be very slow due to latency and they should consider a thin client solution.
However the development manager knew better, Every week we would have a meeting about the performance and every week I said it was a latency issue and couldn't be resolved as we had said initially.
It came to a head in the twixmas period, which was really a slow period because we were in full change freeze. The development manager said that they were having problems with a piece of software and he had read the manual which said that the network must have a 'ping latency' of 8-10ms or less and that If the network team couldn't FIX the network VPN to India he would have to report our incompetency to the the IT director. I downloaded the manual for the software and the first paragraph said in capital letters "this product will only work on a LAN with a latency of 8-10ms. It will not work over a WAN"
I calmly replied to to the development manager that manufactures of the software stated that it would not work over a WAN, so a WWAN was out of the question. I then proceed to describe the lengthy calculations explaining why even with dedicated circuit, utilizing loss-less equipment, the most perfect fibre-optic and copper connections, the wind in the correct direction, etc, the best latency we could get on the 9000 mile round trip from London to Mumbai would be 80-90ms. I finished it off with the following
"I'm sorry that due to the laws of physics we can't provide you with the service you require. However I have read that CERN are doing some amazing work on theoretical quantum teleportation, and as soon as they prove this and release the associated technology to us we will endeavor to install it as soon as possible"
I ensured that the IT director was cc'd in.
The thin client project was initiated shortly afterwards.