Using destination codes 339Programming Operations GuideWhy use destination codes?Routes determine path (line or pool) and any required access numbers.Destination codes determine which route to take (i.e. an end node uses one destination code for allother nodes in the system). If you choose to use the destination codes Normal schedule, the callwill always go out over the same route. If you choose to use the other destination codes schedules,you can set up a more responsive plan, whereby calls can go out over more than one route, basedon scheduled times.Destination codes provide you with the opportunity to create a dialing plan that allows users toconnect to other systems in a relatively seamless or consistent manner, regardless of the lines orroutes that are being used to get there. For example, connecting through VoIP lines requiressignificantly different ways of dialing than dialing over T1 lines. However, you can configuredestination codes, such that the user dials the same number of digits regardless of the trunks overwhich the calls are routed.Figure 101 Using destination codes to access another systemUser dials9-1-601-555-22229-1-601-555-222291 is a destinationcode – system usesRoute 001 and LinePool ARouting tablesabsorb 91-601-555-2222 Dialout programming tells thesystem to add the accesscode for long distance(e.g. 10222)10222-1-601-555-2222External lines recognize thelong distance access code andswitch to the appropriatecarrier1-601-555-2222Call is directed inthe public system
