Page 188 of 254 Alternative Call Routing for Network Bandwidth ManagementNN43001-308 Standard 01.02 May 20074 The main office determines the RLI and uses a DMI to change the dialednumber into a PSTN/MCDN format number.5 The call is routed over the PSTN/MCDN to the telephone at the branchoffice.With the ALTPrefix digits inserted, the resulting number must be one thatCDP or VNR software can process as a steering code.The steering code allows the call to be translated and referenced to a RouteList Index from which the system chooses the alternate route. The digitmanipulation capability of CDP allows digits (such as the ALTPrefix) to bedeleted and it can insert digits so the resulting number is appropriate for thealternate route choice selected (PSTN or MCDN). For example, you canmanipulate the digits for PSTN routes so that DID destinations are dialable.Dialing plansConsider the many ways that calls can be dialed in a network. Astation-to-station call can be dialed using the following:• Directory Number (DN)• Coordinated Dialing Plan DN (starting with a Local Steering Code orDistant Steering Code)• Uniform Dialing Plan DN (starting with a Location Code or HomeLocation Code)• Transferable DN (TNDN) or Group Dialing Plan DNMain offices and branch offices must be able to translate the calls, after theALTPrefix is inserted, using CDP or VNR. Take into account the format ofthe calls with an ALTPrefix inserted prior to the rest of the digits.IMPORTANT!For SRGs, the main office manipulates the digits in the call into aformat appropriate for routing from the SRG on PSTN/MCDN trunks.For more information about SRG, see Main Office Configuration Guidefor SRG 50 (NN42120-501).
