CCS(Collect Call System) has billing manager, signal processing module and IVR processing module. Carriers issue the card PIN number for promotion, manage black list, authenticate subscriber,
differential charging per country/time zone/subscriber class and monthly settlement using Billing Manager. Signaling processing module control the call and do No.7/VoIP signal process. IVR
processing module has the role of setting the In/Out-bound channel, announcement play, DTMF reception and scenario control