Answer to Problem 7

Each call reserves bandwidth resources from a link, reducing the available bandwidth on the lines. So, a direct trunk line can become "full with calls", requiring a search for alternative paths.

Unlike data packets, voice samples in the telephone network do not have headers (all metadata is inferred from the timing of the call). Calls therefore cannot be made to wait in a queue for bandwidth to become available (i.e. the store-and-forward), because the timing information would become lost.