The following items will test your grasp of the material covered in this lesson. There is only one correct
answer for each item. When you complete the exercise, check your answers with the answer key that
follows. If you answer any item incorrectly, study again that part of the lesson which contains the
For questions 1 through 9, match the description in the left column with the corresponding answer in the
Only one path in or out.
A single circuit between two switchboards.
Trunks with identical transmission characteristics
between two switchboards.
Calls completed versus calls attempted.
Average number of calls made per hour.
Amount of time a telephone is off at the hook or in use.
Traffic that flows through a switch, but does not begin or
end at the switch.
International unit of measurement for traffic intensity.
A switchboard that has more than one possible path in or
out for all traffic.
10. In the final step of calculating trunk group sizing, you
must use the Erlang charts. What do you do to your
Round the value up
Round the value down