Bulk SMS are sent using Web Based Interface and works on A2P(Application to Person) protocol.One can use HTTP, XML and SMPP for API Connectivity to the Platform. Sender ID can be masked using these applications. Registered Telemarketers get marketing data from Telcos. They filter DND data and sends promotional bulk sms via using these A2P Softwares. These softwares use multiple SMSCs to control the message traffic load. But Many Non-Registered Telemarketers get data in wrong way and send promotional messages to any random numbers. Because the are not registered telemarketers, hence they do not get data of DND customers from TRAI or Telcos and sent Bulk messages to each and every subscribers. And thats the reason we get spam messages inspite of being active in NCCP Database.