Alternative Call Routing for Network Bandwidth Management Page 189 of 254Main Office Configuration for SRG200/400 Release 1.5 Configuration GuideBefore deciding whether to program the steering codes as Distant SteeringCodes (DSC) or Trunk Steering Codes (TSC), take into account that thesystem counts the digits in calls that start with a DSC.Without Flexible Numbering Plan (FNP), DSC calls must have the samenumber of digits as specified in LD 86 ESN (the NCDP prompt). With FNP,fewer digits are acceptable, if the FLEN prompt is programmed correctly.The maximum length of a CDP DN is seven digits (if DNXP is not equipped),and ten digits, if DNXP is equipped. For more information, see Dialing PlansReference (NN43001-283).Calls preceded by the ALTPrefix can be handled by the Vacant NumberRouting (VNR) feature. Use Flexible Numbering Plan (FNP) software forthis type of routing.Examples of Alternative Call Routing for NBWM in operationThe main office systems shown in the diagrams in this chapter are CS 1000Ssystems. However, this feature is supported on any CS 1000 system.A call from a branch office telephone to a main office telephoneFigure 63 on page 190 shows two CS 1000 systems. The system shown on theleft is a main office. The system shown on the right is a branch office. Bothsystems have access to the PSTN. The Wide Area Network (WAN) is shownin the center with a gatekeeper/Network Routing Service (NRS) that can beco-resident with a Signaling Server. IP Phones are also shown associated witheach system. Telephone A belongs to the main office. Telephone B is atelephone at the branch office registered to the main office. There are twobandwidth zones indicated by the dashed line (main office zone - MO zoneand branch office zone - BO2 zone). Telephone A and the Media Gatewaybelong to the MO zone. The branch office and Telephone B belong to theBO2 zone.
