<p>As with extension numbers, TIM automatically picks up unallocated trunk numbers as soon
as they are used to make or receive a call. All newly-discovered
trunks are placed in a group called New Trunks as shown below.</p>

<img class="screenshot" src="http://www.tri-line.com/common/img/documentation/tim_professional/setting_up_trunks.png" alt="Setting Up Trunks" />