Providing anonymity services in SIP

Anonymity in telecommunication services means much more than protecting the identity of participants. It requires mechanisms and protocols that unlink the communication parties, unlink users from their location, and avoid statistical analysis. These functional requirements apply also when providing anonymity services to SIP, whereas the identities of caller and the callee(s) should be secured. On the other hand, SIP introduces additional functional requirements to any anonymity services, such as time limitations for session establishment, involvement of several functional entities, inter-domain communications and support of streaming services when the call is established. Here, we propose the usage of a privacy enhancement framework, called Mist, as a solution to the anonymity issue in SIP. For achieving anonymity, the original Mist architecture was modified to be adapted in the SIP framework. The paper discusses how Mist can be adapted to SIP and efficiently support anonymity features.