ROLL RPL IETF 77 status

1. ROLL RPLIETF 77 status draft-ietf-roll-rpl Tim Winter Pascal Thubert Design Team IETF 77 – Roll WG – March 2010

2. RPL Status • New version draft-ietf-roll-rpl-07 • DIO relatively stable • DAO refined • for mixed source route and stateful • S flag, DTSN • New examples in appendix B • New companion drafts: • draft-ietf-roll-of0 • draft-levis-roll-trickle • draft-hui-6man-rpl-option IETF 77 – Roll WG – March 2010

3. Room for simplification • S-flag (related to #26 and LSRR) • T-flag (vs DODAG sequence only) • Prefix in DIOs • Consistency (what, when) IETF 77 – Roll WG – March 2010

4. Major Open Tickets • #17: replacing hash with DTSN • #21: control bits in flow label • #23: OCP object • #24: P2P Discussion • #25: RPL satisfying the MUST reqs • #26: storing / non-storing / mixed • #27: DAO ACK • #28: Source Route Failure IETF 77 – Roll WG – March 2010

5. Ticket #17: LSRR updates • Problem: Updating source route path when parent moves. • Question: Do we cache source routes? How do we trigger updates? Cost of the update? • Proposed approach: • DTSN triggers updates in the Source Route SUBDAG • S-flag avoids the O(Children) problem • #26 is opened to assert the need of mixed mode • Ticket owner: Pascal Thubert IETF 77 – Roll WG – March 2010

6. Ticket #21:Flow Label • Problem: Data packets need an instance ID field. • Question: Relationship with flow label? • Proposed approach: • Packets MAY have a hop-by-hop header that specifies instance ID. This header does not escape the RPL network. • If a packet does not have this hop-by-hop header, RPL assumes the instance ID is embedded in the flow label. • Gateway defaults RPL-inbound packets to instance ID 0. • Gateway decides whether to insert header based on signaling external to RPL specification. • Ticket owner: Philip Levis IETF 77 – Roll WG – March 2010

7. Ticket #23 OCP Object • Question: Should RPL or Metrics draft specify the OCP object? • Background: • Historically RPL draft did include the OCP code (as member of DIO base) • OCP object was subsequently introduced and migrated to metrics draft • As of RPL-07 inconsistent text to OCP object has been removed, leaving metrics draft to ‘own’ OCP object • RPL interface to OFs may now be left somewhat ambiguous • Next Step: Clarify in RPL the interface to Ofs • Ticket owner: Tim Winter Slide #7 IETF 77 – Roll WG – March 2010

8. Ticket #24 P2P Performance • Question: How do we make RPL really support P2P? • Background: • - Use RPL for P2P raised concerns in terms of path cost • (potential issue in terms of battery) • Issue when sending traffic to nodes that do not maintain connectivity • (reactiveness) • Next Step: Use reactive DIS message across the DODAG • TTL = 5 • Forward limited # of DIS copies (dampening) • Collect source route in DIS message • Option: Piggyback (short) data msg to DIS message • Ticket owner : Anders Brandt Slide #8 IETF 77 – Roll WG – March 2010

9. Ticket #25: RPL Satisfying the MUST requirements • Question: Does RPL (rev-07) satisfy the requirements? • Proposed approach: • List all MUST spelled out in RFC5548, RFC5673, « home routing » and « building routing » requirements documents. • Some of the MUST might now be seen as not sufficiently acurrate • Some of you mentioned that some requirements were missing (say it before !!). Still we can look at them, but won’t start again the requirements analysis. • Matrix will be built and sent to the list • Reasonable to not satisfy a MUST if clearly justified. • Ticket owner: JP Vasseur IETF 77 – Roll WG – March 2010

10. Ticket #26: Mixed Operation • Problem: Mixed mode leads to complex behaviours • Question: Should RPL specify operation in either a storing or non-storing (but not mixed) mode for down routes? • Proposed approach: • DIO control field to signal mode of operation as storing or non-storing (allow for future specification of mixed modes). • All nodes MUST support non-storing operation (source routing, LSRR or DAO?). • Nodes MAY support storing operation (hop-by-hop routing, DAO). Nodes without adequate resources participate as leaves only. • Key design point; further feedback from WG? • Ticket owner: Tim Winter Slide #10 IETF 77 – Roll WG – March 2010

11. Ticket #27: DAO Ack • Problem: DTSN covers the loss of DIO because of LLN. • Question: Should we also protect DAO? • Proposed approach: • none yet • we are still picking advice from the list. • Ticket owner: Pascal Thubert IETF 77 – Roll WG – March 2010

12. Ticket 28: Source Route Failure • Problem: Source route used to support non-storing nodes • Question: What action to take when source route fails? • Approaches: • Possible actions: • Drop packet and do nothing • Drop packet and send back ICMP error • Drop packet and send back RPL message • Backtrack by sending packet towards root • Possible uses: • Specify only a single action to take • Allow different actions on a per-instance/dag/packet basis • Ticket owner: Jonathan Hui IETF 77 – Roll WG – March 2010

13. Other Room for refinement • Generic Role of OF • Parameters • DIO vs. OF vs. Spec vs. implementation • Movement • When to move, jump, migrate • DAO • When to proactively push a DAO • When to pull DAOs using DTSN and T bit. IETF 77 – Roll WG – March 2010

14. Miscellaneous/editorial • Reporting to the root • Eg Request a global repair • Options in DIS • Security, filters, • Still some inconsistencies • DAG vs. DODAG IETF 77 – Roll WG – March 2010