PSYCHIC SHOE REPAIR
That is a real sign on Thomas Road in Phoenix Arizona. It is also the summary of what some enterprise managers want in terms of obtaining telemetry for performance measurement in data networks.
One cannot use the network to measure the network. One cannot have access to capture data packets. Existing enterprise tools, that they provide, do not have any capacity to give one critical performance data. How then is one to do performance engineering?
The answer was there on the sign all the time!