1.2 Network Devices and Numbering PlanGetting Started 7PBX Numbering InformationPBX numbering information is necessary to setup phone numbers for a VoIP network.Configure the numbers conforming to existing PBX numbering systems.Dialling ExamplesThe VoIP network allows you to access the PBX at one location from another to establish: (1)an extension call, or (2) an outside call through local PSTN as if you are calling from the samearea.Calling from Los Angels to ChicagoTo extension 301 via IP networkTo local telephone 123-4567 via IP network through local PSTNDescription Los AngelsOfficeChicagoOfficePBX OfficeCodeA unique number (ranging from 1 to 8 digits)assigned to identify each Hybrid IP-PBX within anetwork. In this example, for convenience, eachPBX Office Code corresponds to the last portion ofthe IP address of its Gateway unit; that is, becauseLos Angels Office unit has the IP address of200.45.11.35, Los Angels PBX Office Code is 35.35 41IP TrunkNumberAn access number to seize an IP trunk. Anyavailable trunk number can be assigned as an IPTrunk Number.801 801PSTN TrunkNumberAn access number to seize a local PSTN trunk. 9 9ExtensionNumberA number assigned to each extension. 200-299 300-399Dial 41.Dial 801. Dial 301.Chicago PBXoffice code extension no.IP trunk no.Dial 41. Dial 9.Dial 801. Dial 123-4567.Chicago PBXoffice code phone no.Chicago PBXPSTN trunk no.IP trunk no.