Richard Good rgood@crg.ee.uct.ac.za

1. CoE Industry Seminar August 2008 Linking Session Based Services with Transport Layer Resources in the IP Multimedia Subsystem Richard Good rgood@crg.ee.uct.ac.za Neco Ventura neco@crg.ee.uct.ac.za

2. Overview • Introduction • Background • Pull Mode Operation with NSIS/NSLP • Push Mode Operation with UE Identity Dinding • Horizontal Co-ordination • SIP Session Setup • Route Discovery Mechanism • IMS Session Use Case Scenario • Testbed Validation and Evaluation • Conclusions and Future Work

3. Background • Multimedia Revolution on the Internet is driven by the Web 2.0 Revolution • Web 2.0 harnesses collective intelligence and has resulted in millions of user power websites with services free of charge • IMS service deployment is threatened – must justify through service differentiation: Increased security, Increased service integration, Increased reliability • Resource Management Framework: 3GPP PCC (3GPP TS 23.203), ETSI TISPAN RACS (ES 282 003), ITU-T RACF (ITU-T Y 211)

4. Pull Mode Operation with NSIS/NSLP • No standardised mechanism for passing tokens into network • No mechanism for discovery interdomain routes and enforcing policies across all traversed segment • Requires total transport layer overhaul and client modifications • ITU-T Y 211, 3GPP TS 23.203, IETF draft-ietf-nsis-qos-nslp

5. Push Mode Operation with UE Identity Binding • Difficult to bind concurrent sessions • No mechanism for discovery interdomain routes and enforcing policies across all traversed segment • ITU-T Y 211, 3GPP TS 23.203, 3GPP TS 23.214

6. Architectural Requirements • Innovative Service Creation • Application Policy Interaction • Automatic Policy refinement • High level technology/vendor independent policy rules -> Low Level technology/vendor dependent configuration parameters • End to End QoS-enabled connectivity across all traversed domains (3GPP TS 29.213 S9 interface) • Limited effect on user utility of network • !STANDARDS BASED!

7. Horizontal Co-ordination • Use SIP routing to determine origin, destination and transit domains – define new AVPs in Diameter Rx interface: Origin/Dest/Transit-Domain • Allows applications to request end to end QoS connectivity from home domain across all traversed transport segment • Assumptions • All services must be SIP based • SIP headers must be visible to traversed proxies • SIP signaling and media traversed domains must be RELATED • PDFs must know neighbouring PDF addresses

8. IMS Session Setup

9. Route Discovery • AF in origin home domain receives response to subsequent SIP request • Determines origin, transit and destination domains of signaling • Encapsulates info in Authorisation Request and sends to PDF • PDF determines media routes as follows • If origin and destination domains are same these are the only involved domains and need resource reservation • If origin and destination domains different but no transit domains these are the only involved domains and need resource reservation • Origin and Destination not equal, and transit domains exist – Auth Request forwarded to PDF in Origin domain which checks involved signaling domains and finds shortest media path by forwarding to neighbouring domains

10. IMS Session Use Case Scenario

11. Testbed Validation • 3GPP TS 23.228 IMS 3GPP TS 29.212 • 3GPP TS 29.213 3GPP TS29.214

12. Scenario Signaling

13. Proof of Concept Results

14. Conclusion and Future Work • Reviewed State of the art regarding Resource Management in IMS • Proposed enhancement to general RMF that allows application to request QoS enabled paths across all traversed transport segments • Further Work – continued validation and evaluation of concepts in real testbed • Project Progress – 3 papers published this year, 2 under review • Projected handin date early January 2009

15. References • G. Camarillo, T. Kauppinen, M. Kuparinen, and I. M. Ivars, “Towards an Innovation Oriented IP Multimedia Subsystem,” IEEE Communications Magazine, March 2007. • F. Baroncelli, B. Martini, V. Martini, and P. Castoldi, “Supporting Control Plane-enabled Transport Networks within ITU-T Next Generation Networks (NGN),” NOMS’08 • S. Obreja and E. Borocci, “Overlay Topology Based Inter domain QoS Paths Builder,” AICT’08 • R. Yavatkar, D. Pendarakis, and R. Guerin, “RFC 2753 – A Framework for Policy-based Admission Control,” 2000. • 3GPP, “TS 23.203 Policy and Charging Control Architecture,” 2007. • 3GPP “TS 29.212 Gx Reference Point”, 2008. • 3GPP “TS 29.213 S9 Reference Point”, 2008. • 3GPP “TS 29.214 Rx Reference Point”, 2008. • ETSI TISPAN, “ES 282 003 Resource and Admission Control Subsystem (RACS) Functional Architecture,” 2006. • ITU-T, “Y 2111 Resource and Admission Control • Functions in Next Generation Networks,” 2006. • C. Rothenberg and A. Roos, “A Review of Policy-Based Resource and Admission Control Functions in Evolving Access and Next Generation Networks JNSM, March 2008. • G. Ash, A. Bader, C. Kapper, and D. Oran, “QoS NSLP QSPEC Template,” Internet Draft, October 2008. • R. Good, F. Gouveia, S. Chen, N. Ventura, and T. Magedanz, “Critical Issues for QoS Management and Provisioning in the IP Multimedia Subsystem,” JSNM, April 2008. • J. Rosenberg et. al., “RFC 3261 - SIP: Session Initiation Protocol,” June2002. • T. Magedanz, D. Witaszek, and K. Knuettel, “The IMS Playground @ Fokus- An Open Testbed for Next Generation Network Multimedia Services,” TRIDENTCOM’05 • R. Good and N. Ventura, “An Evaluation of Transport Layer Policy Control in the IP Multimedia Subsystem,” PIMRC’08 • D. Waiting, R. Good, R. Spiers, and N. Ventura, “Open Source Development Tools for IMS Research,” TRIDENTCOM’08 • J. Song, M. Chang, and S. Lee, “Overview of ITU-T NGN QoS Control,” IEEE Communications Magazine, September 2007.

16. Questions and Comments Richard Good rgood@crg.ee.uct.ac.za