Hi; I made that IETF98 presentation. Currently, the maximum frame size that IEEE 802.15.4 can handle is either 127 octets or 2047 octets. The 2047 octet limit is for Higher Rate 2 Mb/s PHY (802.15.4t), Smart Utility Networks (SUN), Television white space (TVWS), railroad communications and control (RCC), and Low energy critical infrastructure monitors (LECIM) FSK PHYs and is 127 octets for all other PHYs.
Pat Pat Kinney Kinney Consulting LLC IEEE 802.15 WG vice chair, SC chair ISA100 co-chair, ISA100.20 chair O: +1.847.960.3715 [email protected] <mailto:[email protected]> On 6, Apr2017, at 8:36, Muhammad Akbar <[email protected]> wrote: Hi What about IEEE 802.15.12? I attended a presentation in IETF98, where a person from IEEE mentioned about IEEE 802.15.12 with the packet size of 2048 (not sure the exact but its more than 1280 MTU), do we need fragmentation then? Muhammad ________________________________________ From: 6tisch <[email protected]> on behalf of Tero Kivinen <[email protected]> Sent: 06 April 2017 13:34 To: Pascal Thubert (pthubert) Cc: PWK; Ralph Droms; Thomas Watteyne; [email protected]; [email protected]; Carsten Bormann Subject: Re: [6tisch] [6lo] Thomas' review of draft-thubert-6lo-forwarding-fragments-04 Pascal Thubert (pthubert) writes: > IEEE 802.5.4 understood and started addressing those issues in their > protocols years ago, consider for instance how this is done at PHY > layer in 802.15.4K LECIM - LP-WAN (cc'ing Pat). In the light of that > art, the legacy 6LoWPAN technique is shamefully inadequate. 802.15.4k is really only a phy level fragmentation, and the main issue there is that the max packet size in that PHY is extremely small (less than 30 octets). When designing the IEEE std 802.15.9 we checked 4k that and realized that it is not something that can be used in general case, and thats why the MAC level fragmentation in the 802.15.9 is using different method. Fragmentation was needed in the 802.15.9 as KMP payloads do not fit to the small frames of 802.15.4. This fragmentation method (and the multiplexing) from the 802.15.9 will most likely be adopted in the 802.15.12 later... Btw, the 802.15.9 is now available using the get IEEE 802 program, and you can download it from http://standards.ieee.org/getieee802/download/802.15.9-2016.pdf The fragmentation wire formats are described in the section 7, and state matchines are described in section 9. > My suggestion to the group is to take a holistic view of these > issues, and redesign or fragment support. This is what my draft > does. The 802.15.9 is hop by hop fragmentation, so if you want to be able to forward fragments, you need to specify your own way of doing that... -- [email protected] _______________________________________________ 6tisch mailing list [email protected] https://www.ietf.org/mailman/listinfo/6tisch BU is a Disability Two Ticks Employer and has signed up to the Mindful Employer charter. Information about the accessibility of University buildings can be found on the BU DisabledGo webpages. This email is intended only for the person to whom it is addressed and may contain confidential information. If you have received this email in error, please notify the sender and delete this email, which must not be copied, distributed or disclosed to any other person. Any views or opinions presented are solely those of the author and do not necessarily represent those of Bournemouth University or its subsidiary companies. Nor can any contract be formed on behalf of the University or its subsidiary companies via email. _______________________________________________ 6lo mailing list [email protected] https://www.ietf.org/mailman/listinfo/6lo
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