Transient BCE for Proxy Mobile IPv6 draft-ietf-mipshop-transient-bce-pmipv6-00.txt

1. Transient BCE for Proxy Mobile IPv6draft-ietf-mipshop-transient-bce-pmipv6-00.txt Oliver Blume (oliver.blume@alcatel-lucent.de) Marco Liebsch (marco.liebsch@nw.neclab.eu) Ahmad Muhanna (amuhanna@nortel.com) MIPSHOP session18th November 2008 IETF#73, Minneapolis

2. History • Individual draft discussed in MIPSHOP at IETF72 in Dublin • draft-liebsch-netlmm-transient-bce-pmipv6-01.txt • Joint effort, which considers 3 previous individual submissions • Acceptance as WG draft in October 2008 • First WG draft published on 27th October 2008

3. Initial WG draft version • Some editorial revision to improve readability • Clarification on use cases • Better section structure and content (section 4.1 and 4.2) • Includes IANA considerations • Revised references structure • Separate informative from normative references

4. Design goals of transient BCE –A Summary • Low added complexity • Avoid new messages and protocol interfaces • No additional SAs required • Meet requirements for a variety of handover use cases • Approach: • Allow utilizing both previous and new connectivity as available during HO • Synchronize downlink path switch with HO characteristics

5. Characteristics of transient BCE • Single option attached to PBU/PBA (new MAG – LMA) • Advanced BCE management on LMA • Maintains temporarily 2 forwarding entries in the MN‘s BCE • Aligns forwarding of uplink packets from both links (pMAG and nMAG) with HO characteristics • Enables controlled forwarding of downlink packets (pMAG or nMAG) to suit various handover cases • Suitable for various handover cases: • dual radio MBB handover • 3GPP single radio handover

6. Problem with PMIPv6 Handover • PBU from nMAG interrupts connectivity via pMAG • Set-up time required for new IP connectivity in new RAN • Packet loss 2. New PBU and HNP retrieval: overwrites binding to pMAG LMA pMAG nMAG 3. Setup of access bearer : takes time (HNP required, RA, address validation…) ? pRAN nRAN 1. Setup of new radio access : triggers new PBU IF1, IF2,… MN

7. Use case DRHO • For dual-radio MN can use previous connectivity during HO (make-before-break) • tBCE signalling enables LMA to maintain routing to pMAG 2. New PBU with Transient Binding option HNP retrieval, but transient binding keeps routing state via pMAG LMA pMAG nMAG 3. Setup of access bearer takes time(HNP required, RA, address validation…) pRAN nRAN 1. Setup of new radio access triggers PBU with Transient Binding optionMN can support simultaneous attachment IF1 IF2 MN

8. Use case SRHO • Some RATs provide handover optimisation on L2, so thatrouting via pMAG is still possible after movement of MN • tBCE signalling enables LMA to maintain routing to pMAG 2. New PBU with Transient Binding option HNP retrieval, but transient binding keeps routing state via pMAG LMA pMAG nMAG 3. Setup of access bearer takes time(HNP required, RA, address validation…) pRAN nRAN 1. Setup of new radio access triggers PBU with Transient Binding optionForwarding mechanism in L2 RAN available IF1 MN

9. Received comments • Comment: ‚Enters the area of PMIPv6 Multi-Homing‘ • Multi-Homing considers different PMIPv6 sessions • Multiple BCEs • Multiple HNPs • Transient BCE has temporarily two forwarding entries in a single BCE • 2 Proxy-CoAs in a single BCE

10. Received comments (cont‘d) • Comment: ‚How long transient state remains alive?‘ • Negotiated Lifetime only a maximum delimiter • Transient state activated in a controlled manner by means of PBU to suit handover case • Comment: ‚Can LMA guess the lifetime ?‘ • MAG is the better entity to activate a transient BCE • Detection of link availability (completed bearer setup or address configuration

11. Received comments (cont‘d) • Comment: ‚Transient State and Lifetime – Implementation vs. Signaling‘ • Static implementation on the LMA performs badly • Optimum Lifetime of transient state not static! • May not address all scenarios • Signaling most efficient as MAG is... • ...appropriate to propose max transient lifetime • ...appropriate to initiate activation of a transient binding • Further comment „Same issue happens to MIPv6...“ • Yes, similar proposal for MIPv6 now available as I-D

12. Received comments (cont‘d) • Comment: ‚There is no issue to solve for use case SRHO‘ • Need of tBCE to support use case SRHO clarified • Delay in setting up access bearer at nMAG • Benefit from existing RAN forwarding • Transient BCE ensures delaying path switch • Concluded offline

13. Received comments (cont‘d) • Comment: ‚Is Make-before-break out of scope?‘ • No, it‘s in scope.Use case DRHO provides a solution for MBB

14. Received comments (cont‘d) • Comment: ‚Effort of introducing new state at LMA‘ • Improvements usually imply extensions... • Comparatively low complexity and easy to implement • Meets the design goals • Timers and signaling for state transitions common in protocols • No new data in the BCE

15. Next • More comments for improvement of the document appreciated • In particular aim at completeness of main protocol operation sections (Sections 4.4 and 4.5) • Consider shortening Section 3 ‚Analysis of the Problem Space‘ ? • Timeline Jan ´09 Feb ´09 March ´09 Oct ´08 IETF73 IETF74 Version 00 Submit toIESG WGLC

16. Questions ? ? ..... ! ! ! ? ? Comments ? ?