Exactly! Keeping in mind that this is an open hand as opposed to “prove yourself and come back (expecting not)”.
One path is: define the HbH header option you rneed, see how you can converge with what Shwetha is showing us (which I was refering to), pick a code that extends 6LoRH https://tools.ietf.org/html/draft-ietf-roll-routing-dispatch-00#section-9.2, work out the compressed form, and go for it with your experimentation… … and please keep this group in the loop. A personal submissions will not do harm! Pascal From: Thomas Watteyne [mailto:[email protected]] Sent: jeudi 25 août 2016 13:23 To: Shwetha Bhandari (shwethab) <[email protected]> Cc: Lijo Thomas <[email protected]>; Pascal Thubert (pthubert) <[email protected]>; [email protected]; Frank Brockners (fbrockne) <[email protected]> Subject: Re: [6tisch] Time to Live - ASN in a packet Lijo, That's great, indeed. My naive response is that, if you find out that there is real value in doing this, we will find a way to fit that information somwhere. Looks like Shwetha's pointers go in that direction. Some HbH header seems suitable, we just have to find a mechanism for matching that those TSCH ASN. My recommendation would be to measure/prove the value first, and embark in standardization after. Thomas On Thu, Aug 25, 2016 at 12:24 PM, Shwetha Bhandari (shwethab) <[email protected]<mailto:[email protected]>> wrote: Hi Lijo, We are trying something similar with In-band OAM – defining HbH options to collect timestamps, node, interface information as the packet traverses the nodes. Please take a look at the following: https://tools.ietf.org/html/draft-brockners-inband-oam-data-01#section-3.1<https://tools.ietf.org/html/draft-brockners-inband-oam-data-01> https://tools.ietf.org/html/draft-brockners-inband-oam-transport-01#section-3.1 Thanks, Shwetha From: 6tisch <[email protected]<mailto:[email protected]>> on behalf of Lijo Thomas <[email protected]<mailto:[email protected]>> Reply-To: Lijo Thomas <[email protected]<mailto:[email protected]>> Date: Thursday, August 25, 2016 at 3:37 PM To: Thomas Watteyne <[email protected]<mailto:[email protected]>>, "Pascal Thubert (pthubert)" <[email protected]<mailto:[email protected]>> Cc: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: Re: [6tisch] Time to Live - ASN in a packet Hi Pascal & Thomas, The problem is inline with Pascal's comment on "looking for per packet information to as to monitor and maybe influence the forwarding and delivery" We are proposing a debt based distributed scheduling scheme where nodes make forwarding decisions based on the PDR and end-to-end delay requirement of flows. We simulated our algorithm using 6tisch simulator and got encouraging results. For this, we plugged in ASN value in the application payload and the intermediate node updates the ASN value before forwarding. Now we are implementing the algorithm on the hardware using OpenWSN environment and intend to do inline with the standard. We are actually contemplating on HbH at L3, similar to RPL RPI as described in RFC 6553 But we would like to understand that if any options is available in the 6tisch framework. Expecting your valuable comments..!!!!!!!!!! Thanks & Regards Lijo Thomas On August 25, 2016 at 1:39 PM "Pascal Thubert (pthubert)" <[email protected]<mailto:[email protected]>> wrote: Hello Lijo: Like Thomas, I’d love to understand what your case and solution approach is. Is asynchronous OAM like the openWSN application enough for you? Or else are you looking for per packet information to as to monitor and maybe influence the forwarding and delivery? In the latter case, your work may be related to other efforts, and if your experimentation is successful then why not consider a more general applicability? All in all I have this feeling that time-aware forwarding is on the way, in which exact shape and form is left TBD: - DetNet is discussing validating the end-to-end latency of individual packets to make sure that the delivery was within bounds. Is that similar to your need? - I’ve participated to work where the QoS of the packet was estimated at each hop depending on whether the packet was early or late vs. a predefined schedule. This makes things much simpler but slightly less deterministic than a tight scheduling. - There’s also OAM work that uses HbH headers to monitor the packets as they flow along the network (IOW, in band as opposed to asynchronous OAM packets) My understanding is that you want HbH behavior. - If you are doing a mesh, you can probable hack a mesh header. - But if you are considering a larger applicability (I hope so!) then you probably want to hack at L3. You can find tons of ideas of what can be done at L3 in various environments in https://tools.ietf.org/html/draft-dt-detnet-dp-alt-03, which is pending adoption call. But if you narrow down to 6TiSCH, then you probably want to design you own option in the HbH header and incode it in a 6LoRH similar to the RPL RPI. You may use ASN to start with, but when going standard you’ll have to abstract that a little bit, even if the data in the packet is unchanged. Very keen to hear more! Pascal From: 6tisch [mailto:[email protected]] On Behalf Of Thomas Watteyne Sent: jeudi 25 août 2016 08:28 To: Lijo Thomas <[email protected]<mailto:[email protected]>> Cc: [email protected]<mailto:[email protected]> Subject: Re: [6tisch] Time to Live - ASN in a packet Lijo, It looks like you are describing two things: the TTL (or hop limit in IPv6 parlance) which decrements by one by each router, and some timestamp which can be used to measure end -to-end latency. I'm assuming the latter. I'm also assuming you are doing this as part of an experiment, to look at the end-to-end/hop-by-hop latency. In that context, you probably aren't looking for standardizing that (or even standards-compliance during your experiment), but more at an implementation technique to keep that information. Of course, the answer depends entirely on the information we are missing. But assuming you are playing with the OpenWSN implementation, there is already an application called rrt which sends the ASN as application payload at the source, and records the ASN when the DAGroot has received that. You can then substract one by the other and do some stats. Please ask further questions to the OpenWSN community [1] as such technical discussion on a particular implementation doesn't belong on the 6TiSCH WG ML. If you are using the commercial SmartMesh IP solution by Linear Tech [2], good news, all of that is already built in. The manager (~DAGroot) keeps track of timing and can send you average latencies for each of your nodes. If you're interested, you can look at these numbers "live" on deployments in Argentina [3,4] or California [5]. As you might imagine, latency/throughput/lifetime trade-off for one another, so there is a handy "performance estimator" tool you can use [6,7]. For further question on this topic, please use www.dustcloud.org<http://www.dustcloud.org>. Finally, looking at lowering latency in 6TiSCH has been an important research topic in the last year or so. Look for example at the "Low-Latency Scheduling Function" [8] work which lowers the per-hop latency to 10's of ms withing the 6TiSCH framework. Thomas [1] www.openwsn.org<http://www.openwsn.org> [2] www.linear.com/dust<http://www.linear.com/dust> [3] http://www.savethepeaches.com/ [4] PEACH: Predicting Frost Events in Peach Orchards Using IoT Technology. Thomas Watteyne, Ana Laura Diedrichs, Keoma Brun-Laguna, Javier Emilio Chaar, Diego Dujovne, Juan Carlos Taffernaberry, Gustavo Mercado. EAI Endorsed Transactions on the Internet of Things, to appear in 2016. [5] http://www.snowhow.io/ [6] http://www.linear.com/docs/42452 [7] Industrial IEEE802.15.4e Networks: Performance and Trade-offs. Thomas Watteyne, Joy Weiss, Lance Doherty, Jonathan Simon. IEEE International Conference on Communications (IEEE ICC), Internet of Things Symposium, London, UK, 8-12 June 2015. [8] LLSF: Low Latency Scheduling Function for 6TiSCH Networks. Tengfei Chang, Thomas Watteyne, Qin Wang, Xavier Vilajosana. IEEE International Conference on Distributed Computing in Sensor Systems (DCOSS), Washington, DC, USA, 26-28 May 2016. On Thu, Aug 25, 2016 at 7:57 AM, Lijo Thomas <[email protected]<mailto:[email protected]>> wrote: Hi all, We are working on problem which needs the Time to Live (TTL) information in terms of ASN to be included as part of the Packet. We require the intermediate nodes to update TTL at each hop. How this information can be passed in a 6tisch framework. Suggestions are welcome.. Thanks & Regards Lijo Thomas ------------------------------------------------------------------------------------------------------------------------------- [ C-DAC is on Social-Media too. Kindly follow us at: Facebook: https://www.facebook.com/CDACINDIA & Twitter: @cdacindia ] This e-mail is for the sole use of the intended recipient(s) and may contain confidential and privileged information. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies and the original message. Any unauthorized review, use, disclosure, dissemination, forwarding, printing or copying of this email is strictly prohibited and appropriate legal action will be taken. ------------------------------------------------------------------------------------------------------------------------------- _______________________________________________ 6tisch mailing list [email protected]<mailto:[email protected]> https://www.ietf.org/mailman/listinfo/6tisch -- _______________________________________ Thomas Watteyne, PhD Research Scientist & Innovator, Inria Sr Networking Design Eng, Linear Tech Founder & co-lead, UC Berkeley OpenWSN Co-chair, IETF 6TiSCH www.thomaswatteyne.com<http://www.thomaswatteyne.com> _______________________________________ ------------------------------------------------------------------------------------------------------------------------------- [ C-DAC is on Social-Media too. Kindly follow us at: Facebook: https://www.facebook.com/CDACINDIA & Twitter: @cdacindia ] This e-mail is for the sole use of the intended recipient(s) and may contain confidential and privileged information. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies and the original message. Any unauthorized review, use, disclosure, dissemination, forwarding, printing or copying of this email is strictly prohibited and appropriate legal action will be taken. ------------------------------------------------------------------------------------------------------------------------------- -- _______________________________________ Thomas Watteyne, PhD Research Scientist & Innovator, Inria Sr Networking Design Eng, Linear Tech Founder & co-lead, UC Berkeley OpenWSN Co-chair, IETF 6TiSCH www.thomaswatteyne.com<http://www.thomaswatteyne.com> _______________________________________
_______________________________________________ 6tisch mailing list [email protected] https://www.ietf.org/mailman/listinfo/6tisch
