service that due to various problems is available only 50% of the
time. So what is the availability that I should report to potential
new customers? 100% 50% or 75% Does it matter that the reason the
one customer has only 50% availability is that the room where the
router at that customer's site is underwater every other day due to
no fault of my own?It is because of these sorts of questions that I never know what
it means when someone says that their network is available 99.9%
Problems with CPE is usually not figured into network uptime.
Now, if it was *your* router at the customer prem, then it would be your
responsibility that you allowed your equipment to, uh, become waterlogged. 
Dave