1. Interconnecting P2PSIP and IMS Jani Hautakorpi¹, Arturo Salinas¹, Erkki Harjula², Mika Ylianttila² ¹Ericsson Research Nomadiclab ²MediaTeam Oulu Group, University of Oulu NGMAST’08 16-19th Sep 2008 Cardiff, Wales, UK

2. NGMAST'082 / 14 Content Motivation and background Interconnection architecture: –Overview –Preliminary procedures –Session establishment from P2PSIP to IMS –Session establishment from IMS to P2PSIP Prototype Future work Conclusions

3. NGMAST'083 / 14 Motivation and Background (1/3) Many ways to communicate Quite often no interconnection mechanisms This lead to separated islands

4. NGMAST'084 / 14 Motivation and Background (2/3) S-CSCF P-CSCF HSS AS SIP P2PSIP network IMS network

5. NGMAST'085 / 14 Motivation and Background (3/3) Excluded topics: –IPv4/IPv6 interworking –NAT traversal –Media handling –Charging

6. NGMAST'086 / 14 Interconnection Architecture (1/6) Overview P2PSIP network IMS network Gateway AS P2PSIP to IMS IMS to P2PSIP

7. NGMAST'087 / 14 Interconnection Architecture (2/6) Preliminary Procedures Gateway AS registers itself to the P2PSIP network IMS users have to set up their iFCs P2PSIP users do not have any preliminary procedures

8. NGMAST'088 / 14 Interconnection Architecture (3/6) Session Establishment from P2PSIP to IMS (1/2) Does the host name match my domain? P2PSIP UA (at p2p-domain.com) Get to H(ims-domain.com) SIP INVITE to IP GW SIP INVITE to user@ims-domain.com IP GW yes no Get to H(user@ p2p-domain.com) SIP INVITE to IP USER IP USER P2PSIP network get INVITE get INVITE Novel URI handling mechanism

9. NGMAST'089 / 14 Interconnection Architecture (4/6) Session Establishment from P2PSIP to IMS (2/2)

10. NGMAST'0810 / 14 Interconnection Architecture (5/6) Session Establishment from IMS to P2PSIP (1/2) P-CSCF HSS Gateway AS IMS UA S-CSCF Evaluate the trigger point in iFC: Session case=Originating Request-URI=*@p2p-domain.com SIP INVITE to user@p2p-domain.com

11. NGMAST'0811 / 14 Interconnection Architecture (6/6) Session Establishment from IMS to P2PSIP (2/2)

12. NGMAST'0812 / 14 Prototype We implemented a prototype from the Gateway AS Used Open IMS Core Used Sofia-SIP Used SIPp Result: Proposed architecture is valid

13. NGMAST'0813 / 14 Future Work Studies related to charging: Probably different mechanisms for each direction Media handling: Possibly a need for intermediary media elements IPv4/IPv6 interworking

14. NGMAST'0814 / 14 Conclusions We proposed an interconnection architecture between P2PSIP and IMS: –Contains novel URI handling mechanism –Does not require changes to IMS terminals Prototype proves that the proposed architecture is valid