11:10-12:10 Thursday Morning session II Grand Ballroom 3 Minutes Taker: [Rahul] [Mohit] Jabber Scribe: [Jing] [Zhen] presenting the milestones 1. Agenda bashing 5 min 2. TCP over Constrained Nodes Carles Gomez Montenegro draft-gomez-lwig-tcp-constrained-node-networks 20 min [Carles] presenting history of draft, updated after ML comments presenting motivation of the draft. TCP is neglescted/critised for IoT ... but may have to be used in several scenarios new characteristic update about link layer of low trans rate < 1Mbps Primary scenario been considered is for constrained networks working with cloud infrastructure. Traversal of middlebox is considered Typicall TCP conn will be initiated by constrained device ... recommendation regarding setting the TCP MSS.. align it with IPv6 MTU Updates to recommendations in window size ... earlier it was one in-flight segment but now it can be increased to say 5-MSS Recommend to use alternate RTO estimation mechanism as compared to CoCoA ... evidence of CoCoA works better as compared to RFC 6298. explains some conflicts of CoCoA mechnaisms with RFC 6298 explains problems of TCP connection lifetimes with the middleboxes .. New ideas of using TCP fast open for short TCP connection lifetime Compare TCP fast open with cookie or open new conn every time new data is to be sent (?) .. Explains SACK mechanism for constrained devices Talks about delayed-Acks from TCP receiver.. Explains UIP characteristics for constrained devices [Rahul] UIP uses buffers for TCP outgoing packets as well .. explains LWIP [Michael Scharf] why the document remommends a lot of aspects not followed by LWIP stack [Carles] Possible excercise for future version ... depending on class of the device it may be useful to classify the implementation. [Suresh]: Have you run it by TCPM people after the latest draft published ? Pls take into consideration michael's comment Still have to address .. need to take into the account some c [thomas]: explains latest update of RIOT-TCP.. expect riot-TCP early next year [Yoshoifumi]: Michaels comment is valid but how to keep it continuously [Suresh]: if the doc is adopted here, it will be better to run the LC on both the WG .... make sense to keep both the WGs such as TCPM and LWIG for this draft [Zhen]: LC can be handled as per suresh suggestion [Zhen]: how many people of read any verion? Answer: 10 [Zhen]: how many would want to keep reviewing? Answer: 5 3. Implementation experiences of public-key cryptography on 8-bit micro-controllers Mohit Sethi https://tools.ietf.org/html/draft-ietf-lwig-crypto- sensors-01 15 min Explains the goal... how hard is it to do pub key crypto on constrained devices ? What kind of perf can be expected from open source libs? Performance of RSA ... small key size is reasonable for certain scenarios ... for larger key size perf undesirable .. Execution time of RSA 2048 key size is unusable For one of the curve, implementation was changed to assembly code and could reduce the perf drastically ... thus getting reasonable perf New libraries for EdDSA available now .. explains the numbers .. explains the reasoning behind such large numbers for key signing for certain use-cases.. Perf numbers for sample app witht the sample setup explained.. Explains that if 8b uproc is able to achieve this perf then the 32b uproc might be able to do lot better.. Message freshness ... how it can be verified in the draft ... Tradeoffs for doing crypto at link/network/transport/app Big change of removing the reference of group keys. Smaller key lengths in the draft are for reference purpose only .. [Carsten]: one of the interesting happening is ... much lower power radio .. it would be nice to have current numbers .. old wisdom was it was always better to avoid sending the pkts ... it would be nice to have the numbers... conventional wisdom is been challenged by newer chips ... [Mohit]: any specific radio to investigate ? [Carsten]: I can lookup and get back .... Thanks We ll ask again on ML for WGLC .. 4. Neighbor Management Policy and Implementation Consideration for 6LowPAN - Rahul A. Jadhav no draft but relevant topic 15 min Discussion on ROLL mailing list about this How is it handled currently in open source implementations and what we did in one of our practical deployments Network sizes can be huge LRU in Contiki: you would get downtime RIOT: First come first serve In continki it is not possible to have the node density How do you compare link quality amond neighbors Neighbor table updates happens in several cases Reservation for direct childs and Pre auth nodes [Michael Richardson]: We should have draft on this Can keep child of direct child also above if direct child is removed You can know when the Auth is done in PANA. Also in other auth [Zhen]: Eviction of direct child? BR is supposed to have larger memory. >>>> Rahul: My BR has same computation capabilities as any other node [Mohit]: We need a draft on this