Insertion loss reduces the wanted signal along the selected route, while isolation and crosstalk describe unwanted coupling from named unselected or simultaneous routes. They solve different budgets and must be stated over the same frequency range, reference planes, temperature and switch state.
Add maximum loss from every switch stage, cable and transition; pre-LNA loss raises receiver noise figure and transmit-path loss reduces delivered power. For leakage, subtract minimum isolation from the maximum aggressor level and compare the residual with damage, compression, blocker or measurement-floor limits. Parallel enclosure and connector coupling can bypass cascaded switch isolation.
Provide the route matrix, aggressor-victim pairs, simultaneous states, source powers, receiver limits and terminations. Verify the assembled network over frequency with enough dynamic range, including adjacent paths and the longest route.