In an effort to provide lawful interception for session initiation protocol (SIP) voice over Internet protocol (VoIP), an interception architecture using session border controller (SBC) is proposed. Moreover, a prototype based on the proposed architecture is implemented. A testbed is set up and tests are carried out in order to analyze the performance and the capability of function entities and interfaces in the proposed architecture. Test results show that SBC interception capability in SIP signaling is superior to that in real-time transport protocol (RTP) media stream. In order to eliminate the possible bottleneck of RTP packets interception in SBC, an analytic model is proposed to investigate the mechanism in which RTP packet's traffics are shared among different SBC media functions. Analysis results show that multiple SBC media functions can share the RTP packets arrival and can significantly decrease RTP packets service time in SBC. Test results also show that delivery function, collect function and their interfaces in the proposed interception architecture have corresponding interception performance and capability with SBC.