This application will help you to estimate the numbers of lines required for PSTN connections (Erlang B) or the number of agents you need in a call centre during an hour. Erlang B: --------- This model is used by telephone system designers. It estimates the number of lines required for PSTN connections or private WIRE connections. Busy Hour Traffic: Number of hours of call traffic during the busiest hour of operation. Blocking: Percentage representing the number of calls that fail due to an insufficient number of avaiable lines. Lines: Number of lines. Erlang C: --------- This model is used to calculate the number of agents you need in a call centre during an hour. . Calls per hour: Number of call during that hour. Call duration: Average call duration. Average Delay: Average delay you will tolerate in answering all your calls.