1.2 Network Devices and Numbering PlanGetting Started 9NoteAn example using the extension number method is provided in "B Alternative NumberingPlan Example".IP Addressing InformationIP addressing information is typically supplied by a network administrator. Consult yournetwork administrator for specific values.PBX Numbering InformationPBX numbering information is necessary to set up phone numbers for a VoIP network. Set thenumbers conforming to existing PBX numbering systems.Los AngelesOfficeChicagoOfficeDescriptionCard IPAddress 200.45.11.35 199.176.64.41Identifies the location of each VoIP GatewayCard in the network during VoIPcommunications. A unique IP address mustbe assigned to each card.DefaultGatewayAddress200.45.11.1 199.176.64.1Identifies the IP address of the primarygateway (typically a router or similar device)that exchanges IP packets with the othergateways on the VoIP network.Subnet MaskAddress 255.255.255.0 255.255.255.0Defines which digits of an IP address areused for the network address and the hostaddress at each network location. A card IPaddress must fall within the same subnet asthat of the default gateway (e.g., router) thatis connected to the card.Los AngelesOfficeChicagoOfficeDescriptionPBX Code 35 41A unique number (ranging from 1 to 7 digits)assigned to identify each PBX within anetwork.In this example, for convenience, each PBXcode corresponds to the last portion of theIP address of its card; that is, because theLos Angeles office card has the IP address200.45.11.35, Los Angeles PBX code is 35.TIE LineAccessNumber7 7 An access number to use the TIE lineservice.PSTN Trunk(CO Line)Number9 9 An access number to seize a local PSTNtrunk (CO line).ExtensionNumber 200 to 299 300 to 399 A number assigned to each extension.