Cisco 521SG Administration Guide - Page 201

Configuring Dial Plans About Dial Plans 8 Acceptance and Transmission of the Dialed Digits When a user dials a series of digits, each sequence in the dial plan is tested as a possible match. The matching sequences form a set of candidate digit sequences. As more digits are entered by the user, the set of candidates diminishes until only one or none are valid. When a terminating event occurs, the IP PBX either accepts the user-dialed sequence and initiates a call, or else rejects the sequence as invalid. The user hears the reorder (fast busy) tone if the dialed sequence is invalid. The following table explains how terminating events are processed. Terminating Event Processing Dialed digits do not match any sequence in the dial plan. The number is rejected. Dialed digits exactly match one If the sequence is allowed by the dial plan, sequence in the dial plan. the number is accepted and is transmitted according to the dial plan. A timeout occurs. If the sequence is blocked by the dial plan, the number is rejected. The number is rejected if the dialed digits are not matched to a digit sequence in the dial plan within the time specified by the applicable interdigit timer. The Interdigit Long Timer applies when the dialed digits do not match any digit sequence in the dial plan. The default value is 10 seconds. The Interdigit Short Timer applies when the dialed digits match one or more candidate sequences in the dial plan. The default value is 3 seconds. A user presses the # key or the If the sequence is complete and is allowed by dial softkey on the IP phone the dial plan, the number is accepted and is screen. transmitted according to the dial plan. If the sequence is incomplete or is blocked by the dial plan, the number is rejected. Cisco Small Business SPA300 Series, SPA500 Series, and WIP310 IP Phone Administration Guide 200