Abstract of

'Sender Scorecards: Prevention of Unsolicited Communication in IMS Networks'

Unsolicited communication is a major issue in digital communications and hence for the networks enabling such communication. With the increasing use of IP Multimedia Subsystem (IMS) networks, protection of time-critical communication, e.g. Voice over IP, from unsolicited messages, becomes an important topic. 3GPP identified and developed various concepts to cope with unsolicited communication in IMS networks (UCI) in 3GPP TR 33.937. The Protection against UCI (PUCI) borrows concepts from traditional email SPAM filtering but needs to adapt to the nature of IMS communication being direct and time critical. In addition to the protection methods identified in TR 33.937 we present a concept which uses a secure and interoperable scorecard which is associated with the caller and the IMS communication. Depending on the outcome of the scorecard evaluation, the receiving domain can take appropriate actions such as denying or allowing a communication attempt. Scorecards are used to generate a standardized exchange format for sender and message related information. Based on 3GPP standards we present an IMS architecture with scorecard elements, including basic operating procedures for the prevention of UCI.