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

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 Slide #2IETF 77 – Roll WG – March 2010

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

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 Slide #4IETF 77 – Roll WG – March 2010

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 Slide #5IETF 77 – Roll WG – March 2010

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 Slide #6IETF 77 – Roll WG – March 2010

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 #7IETF 77 – Roll WG – March 2010

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 #8IETF 77 – Roll WG – March 2010

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 Slide #9IETF 77 – Roll WG – March 2010

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 #10IETF 77 – Roll WG – March 2010

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 Slide #11IETF 77 – Roll WG – March 2010

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 Slide #12IETF 77 – Roll WG – March 2010

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. Slide #13IETF 77 – Roll WG – March 2010

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