Answer: a) busy hour b) Average handle time.
Explanation:
a) In order to design a telephony circuit, trunk, or call center, it is needed to take into account the busiest calling hour (as a "sliding" 60-minute period) in one day, or week, month or year, generally calculated as an average.
This period is called the "busy hour" and is used to compute the traffic intensity, in Erlangs, considering that if the circuit is busy 100% of the time during 3600 seconds, it will be cursing 1 Erl of traffic.
This traffic can result from 60 calls of 1 min each, 36 calls of 100 sec each, or any combination that have the same outcome of 1 Erl.
b) In order to define, for instance, the number of employees in a call center, a very important parameter is the average time used for each call, adding the queuing time, the true talk time and any other time needed to set up a successful call, i.e., the time that the subscriber stays on the phone after putting the call.
This time is known as AHT (Average Handle Time).