Dial Plan Concepts and Overview 31Call Process Flow The dial plan configuration file is a key component of inbound andoutbound call processing. The dial plan tables in the configuration fileprocess incoming calls in this order:1 Incoming Dial Plan Table2 Pretranslator TableThe dial plan tables process outgoing calls in this order:1 Internal Dial Plan Table2 Least Cost Routing TableAfter pretranslation (if performed), the final translation process routes thecall to the destination.Inbound andOutbound CallProcessingThe system routes all inbound and outbound calls through the dial plan.Inbound Call ProcessingThe system processes inbound calls using the Incoming table. The systemcan also use pretranslators to perform digit manipulations on incomingcalls before it uses the Incoming table.Each pretranslator operation performs a digit manipulation operation onthe dialed digits. For incoming calls, if the DID/DDI range matches theinternal extensions, the dial plan requires no pretranslator. However, youcan use pretranslators to map nonmatching dialed numbers on anincoming DID/DDI channel to desired internal extensions. See theexample in Customer Requirement 1 in “Sample Solutions Using Dial PlanConfiguration File Commands” on page 124.Outbound Call ProcessingThe system processes outbound calls using the Internal dial plan table orthe Least Cost Routing table. You can add entries to the Internal dial plantable to match the system to your service. See Customer Requirement 2in “Sample Solutions Using Dial Plan Configuration File Commands” onpage 124.If you have entries in both the Least Cost table and the Internal table forthe same purpose, the behavior of the dial plan can be confusing. 3Comrecommends that you accomplish least cost routing using Internal Tableentries. For more information, see TimedRoute Create, TimedRouteEntryCreate, and TimedRouteOperation Create later in this chapter.
