Transient BCE for Proxy Mobile IPv6 draft-ietf-mipshop-transient-bce-pmipv6-00.txt Oliver Marco Ahmad MIPSHOP session 18 th November 2008 IETF#73, Minneapolis

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 27 th October 2008

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

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

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

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

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 LMA pMAGnMAG pRANnRAN MN IF1 1. Setup of new radio access triggers PBU with Transient Binding option MN can support simultaneous attachment 3. Setup of access bearer takes time (HNP required, RA, address validation…) 2. New PBU with Transient Binding option HNP retrieval, but transient binding keeps routing state via pMAG IF2

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

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

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

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

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

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

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

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 Oct ´08 Version 00 Jan ´09 IETF73 Feb ´09March ´09 IETF74 Submit to IESG WGLC

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