282 CHAPTER 11: DIAL PLAN4 Click Apply and then click OK to confirm.The system imports the modified dial plan and displays the results of theerror and consistency checks.5 To correct any errors, edit the file and click Apply. You might be requiredto make changes based on warning messages.Outdialing PrefixSettingsA telephone user can use the telephone display panel to look up a call inthe call logs (Missed Calls, Answered Calls, and Dialed Calls), select atelephone number from any of the logs, and redial it.To redial a number from the Missed Calls or Answered Calls list, thesystem must know the appropriate dial prefix to prepend to the digits inthe telephone number.For information about and examples of how to configure outdialingprefixes, see the online Help.ManagingExtensionsThis section describes how to add, change, and manage extensions:■ Extension Settings Overview■ Changing Extension Length and Ranges■ How Auto Discovery Assigns Extensions■ Modifying Extensions■ Converting ExtensionsExtension SettingsOverviewThe system establishes connections between extension numbers. Theconcept of an extension applies to more than just telephones. Extensionsare also assigned to applications such as Call Park zones, AutoAttendants, hunt groups, Line Card ports, voice mail ports, and virtualdevices such as the pcXset™ PC soft telephone Client and theConneXtions H.323 Gateway.The extension length (either 3 or 4 digits), which applies to all extensionson a system, indicates that all extensions contain that number of digits.You cannot mix 3-digit and 4-digit extensions within the same system.Systems support 3-digit and 4-digit dial plans, although there are somedifferences in the extension ranges as noted in these tables. By default,
