Erlang B  

Erlang B is a modeling formula used to determine the probability of call loss on a group of gateways/trunks. Erlang B can calculate any one of the following three factors if the other two are known:

• Busy Hour Traffic - the number of hours of call traffic during the busiest hour of operation
• Grade of Service: the percentage of calls that are blocked because not enough lines are available
• Gateways/Trunks Optimal - the number of lines required to handle the call traffic.

The information commonly provided in reports is Peak Busy Hour, Grade of Service, Gateways/Trunks Optimal, Gateways/Trunks Configured, and Percent of Capacity.

Note: The Erlang B reports may be used to monitor current usage on a regular basis by scheduling a report to automatically run at a specified date and time.