--- 1/draft-ietf-lwig-6lowpan-virtual-reassembly-01.txt 2020-03-09 16:16:22.436401842 -0700 +++ 2/draft-ietf-lwig-6lowpan-virtual-reassembly-02.txt 2020-03-09 16:16:22.488403159 -0700 @@ -1,19 +1,19 @@ Network Working Group C. Bormann Internet-Draft Universitaet Bremen TZI Intended status: Informational T. Watteyne -Expires: September 12, 2019 Analog Devices - March 11, 2019 +Expires: September 10, 2020 Analog Devices + March 09, 2020 Virtual reassembly buffers in 6LoWPAN - draft-ietf-lwig-6lowpan-virtual-reassembly-01 + draft-ietf-lwig-6lowpan-virtual-reassembly-02 Abstract When employing adaptation layer fragmentation in 6LoWPAN, it may be beneficial for a forwarder not to have to reassemble each packet in its entirety before forwarding it. This has been always possible with the original fragmentation design of RFC 4944. Apart from a brief mention of the way to do this in Section 2.5.2 of the 6LoWPAN book, this has not been extensively @@ -28,47 +28,47 @@ Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on September 12, 2019. + This Internet-Draft will expire on September 10, 2020. Copyright Notice - Copyright (c) 2019 IETF Trust and the persons identified as the + Copyright (c) 2020 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Reassembly buffers . . . . . . . . . . . . . . . . . . . . . 3 3. Virtual reassembly . . . . . . . . . . . . . . . . . . . . . 3 4. Header compression . . . . . . . . . . . . . . . . . . . . . 4 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 6. Security considerations . . . . . . . . . . . . . . . . . . . 4 - 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 7.1. Normative References . . . . . . . . . . . . . . . . . . 4 + 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 + 7.1. Normative References . . . . . . . . . . . . . . . . . . 5 7.2. Informative References . . . . . . . . . . . . . . . . . 5 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction 6LoWPAN [RFC4944] is the seminal standard for the transmission of IPv6 packets over IEEE 802.15.4 networks and has served as a blueprint for a number of related standards addressing low-power radios and other IoT connectivity solutions (the "6Lo suite"). @@ -83,21 +83,21 @@ When employing adaptation layer fragmentation on constrained-node networks [RFC7228], it may be beneficial for a forwarder not to have to reassemble each packet in its entirety before forwarding it. This has been always possible with the original fragmentation design of RFC 4944. Apart from a brief mention of the way to do this in Section 2.5.2 of the 6LoWPAN book [BOOK], this has not been extensively described in the literature. The present document attempts to fill that gap. - [I-D.watteyne-6lo-minimal-fragment] provides additional context and + [I-D.ietf-6lo-minimal-fragment] provides additional context and discussion about handling fragment forwarding in the 6Lo standards suite. 2. Reassembly buffers An adaptation layer implementation for 6LoWPAN needs to perform reassembly of every fragmented packet received in order to be able to forward the packet (re-fragmenting it in the process). A reassembly buffer for 6LoWPAN contains: @@ -173,40 +173,49 @@ here.) This makes sure an additional fragment only needs to be sent if the header expansion during forwarding would have created an additional fragment with full reassembly as well. 5. IANA Considerations This document makes no requests of IANA. 6. Security considerations - TBD + There are many security considerations with using fragmentation in + the first place, even with adaptation layer fragmentation (which is + not accessible outside the range of that adaptation layer). Some of + the more specific ones are documented in + [I-D.ietf-6lo-minimal-fragment] and will not be duplicated here. + + In general, sending on fragments early from a node will relieve the + node that is doing the forwarding, but put additional onus on the + next node. This may or may not be in favor of an attacker. 7. References 7.1. Normative References [RFC4944] Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler, "Transmission of IPv6 Packets over IEEE 802.15.4 Networks", RFC 4944, DOI 10.17487/RFC4944, September 2007, . 7.2. Informative References [BOOK] Shelby, Z. and C. Bormann, "6LoWPAN", John Wiley & Sons, Ltd monograph, DOI 10.1002/9780470686218, November 2009. - [I-D.watteyne-6lo-minimal-fragment] - Watteyne, T., Bormann, C., and P. Thubert, "LLN Minimal - Fragment Forwarding", draft-watteyne-6lo-minimal- - fragment-02 (work in progress), July 2018. + [I-D.ietf-6lo-minimal-fragment] + Watteyne, T., Thubert, P., and C. Bormann, "On Forwarding + 6LoWPAN Fragments over a Multihop IPv6 Network", draft- + ietf-6lo-minimal-fragment-14 (work in progress), March + 2020. [RFC6282] Hui, J., Ed. and P. Thubert, "Compression Format for IPv6 Datagrams over IEEE 802.15.4-Based Networks", RFC 6282, DOI 10.17487/RFC6282, September 2011, . [RFC7228] Bormann, C., Ersue, M., and A. Keranen, "Terminology for Constrained-Node Networks", RFC 7228, DOI 10.17487/RFC7228, May 2014, .