Blocking Unsolicited Voice Calls Using Decoys for the IMS

Spam has been a serious problem for email causing frustration and annoyances to customers. This problem is growing at a fast rate with no signs of abating. Another form of spam that has just surfaced is VoIP spam called SPIT (Spam over Internet Telephony). Currently, VoIP has seen an increasing number of users due to the cheap rates. With the introduction of the IMS (IP Multimedia Subsystem), the number of VoIP users are expected to increase dramatically. Recent solutions proposed to block SPIT have the following shortcomings: restricting the users to trusted senders, causing delays in voice call set-up, reducing the efficiency of the system, and requiring dramatic changes in the protocols being used. We propose a decoying system to ban SPIT senders. This decoying system for the IMS, fits well with the existing protocol structure, and customers are oblivious of its operation. Additionally, the decoying method causes no delays in voice call set-up. Further, we will implement a test bed for proof of concept and test robustness of the design.