1 TAC2000/ IP Telephony Lab An Architecture for IMS-based Anti-SPIT Services Dr. Quincy Wu National Chi Nan University, Taiwan

2 TAC2000/ IP Telephony Lab Outline  Introduction SPIT SPIT  IP Multimedia Subsystem (IMS)  Anti-SPIT with IMS  Conclusion

3 TAC2000/ IP Telephony Lab Introduction  Advantage of VoIP  Problem of SPIT  Existing SPAM countermeasures may not be applied to SPAM calls directly  Currently most anti-SPIT solutions are proprietarily bundled on the VoIP Server. We proposed an architecture to allow 3 rd party service creation. We proposed an architecture to allow 3 rd party service creation.

4 TAC2000/ IP Telephony Lab Call Flow for IMS Session Setup P-CSCF I-CSCF S-CSCF I-CSCF Home Subscriber Server S-CSCFP-CSCF Application Server CallerCallee Visited Domain Home Domain

5 TAC2000/ IP Telephony Lab Example of AS: PTT

6 TAC2000/ IP Telephony Lab Design of Anti-SPIT Application Server P/I/S-CSCF Home Subscriber Server P/I/S-CSCF ISC Sh SIP ISC CallerCallee Voice mailbox User Profile Call Control Blacklist/Whitelist Application Server

7 TAC2000/ IP Telephony Lab Signaling Flow of Anti-SPIT AS

8 TAC2000/ IP Telephony Lab Conclusion  Advantages Do-Not-Call List Do-Not-Call List DNS Black List DNS Black List All forwarded to voic All forwarded to voic  Integration with existing services SCIM (Service Capability Interaction Management) SCIM (Service Capability Interaction Management)