Internet Research Task Force, Coding for Efficient Network Communications Research Group (NWCRG) document, work in progress, https://datatracker.ietf.org/doc/draft-roca-nwcrg-rlc-fec-scheme-for-quic/This document specifies Sliding Window Random Linear Code (RLC) Forward Erasure Correction (FEC) Schemes for the QUIC transport protocol, in order to recover from packet losses

Montpetit, Marie-Jose

Roca, Vincent

Swett, Ian

HAL-Rennes 1

Sliding Window Random Linear Code (RLC) Forward Erasure Correction (FEC) Schemes for QUIC

INRIA a CCSD electronic archive server

HAL Id: hal-01919876https://hal.inria.fr/hal-01919876Submitted on 12 Nov 2018HAL is a multi-disciplinary open accessarchive for the deposit and dissemination of sci-entific research documents, whether they are pub-lished or not. The documents may come fromteaching and research institutions in France orabroad, or from public or private research centers.L’archive ouverte pluridisciplinaire HAL, estdestinée au dépôt et à la diffusion de documentsscientifiques de niveau recherche, publiés ou non,émanant des établissements d’enseignement et derecherche français ou étrangers, des laboratoirespublics ou privés.Sliding Window Random Linear Code (RLC) ForwardErasure Correction (FEC) Schemes for QUICVincent Roca, Ian Swett, Marie-Jose MontpetitTo cite this version:Vincent Roca, Ian Swett, Marie-Jose Montpetit. Sliding Window Random Linear Code (RLC) ForwardErasure Correction (FEC) Schemes for QUIC. 2018. ￿hal-01919876￿nwcrg                                                            V. RocaInternet-Draft                                                     INRIAIntended status: Informational                                  I. SwettExpires: December 23, 2018                                        Google                                                          M-J. Montpetit                                                          Triangle Video                                                           June 21, 2018Sliding Window Random Linear Code (RLC) Forward Erasure Correction (FEC)                            Schemes for QUIC              draft-roca-nwcrg-rlc-fec-scheme-for-quic-00Abstract   This document specifies Sliding Window Random Linear Code (RLC)   Forward Erasure Correction (FEC) Schemes for the QUIC transport   protocol, in order to recover from packet losses.Status of This Memo   This Internet-Draft is submitted in full conformance with the   provisions of BCP 78  and BCP 79 .   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 December 23, 2018.Copyright Notice   Copyright (c) 2018 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 ofRoca, et al.            Expires December 23, 2018               [Page 1] Internet-Draft                RLC for QUIC                     June 2018   the Trust Legal Provisions and are provided without warranty as   described in the Simplified BSD License.Table of Contents   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2   2.  Definitions and Abbreviations . . . . . . . . . . . . . . . .   3   3.  Procedures  . . . . . . . . . . . . . . . . . . . . . . . . .   3     3.1 .  Source Symbols Mapping  . . . . . . . . . . . . . . . . .   3     3.2 .  Pseudo-Random Number Generator (PRNG) . . . . . . . . . .   4     3.3 .  Coding Coefficients Generation Function . . . . . . . . .   4   4.  Sliding Window RLC FEC Scheme over GF(2^^8) when Protecting a       Single QUIC Stream  . . . . . . . . . . . . . . . . . . . . .   4     4.1 .  Formats and Codes . . . . . . . . . . . . . . . . . . . .   4       4.1.1 .  Configuration Information . . . . . . . . . . . . . .   4       4.1.2 .  REPAIR Frame Format . . . . . . . . . . . . . . . . .   5       4.1.3 .  Additional Procedures . . . . . . . . . . . . . . . .   6     4.2 .  FEC Code Specification  . . . . . . . . . . . . . . . . .   6       4.2.1 .  Encoding Side . . . . . . . . . . . . . . . . . . . .   6       4.2.2 .  Decoding Side . . . . . . . . . . . . . . . . . . . .   6   5.  Sliding Window RLC FEC Scheme over GF(2^^8) when Protecting       Several QUIC Streams  . . . . . . . . . . . . . . . . . . . .   6   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   7   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7   8.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   7   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   7     9.1 .  Normative References  . . . . . . . . . . . . . . . . . .   7     9.2 .  Informative References  . . . . . . . . . . . . . . . . .   8   Authors’ Addresses  . . . . . . . . . . . . . . . . . . . . . . .   81.  Introduction   QUIC [ QUIC-transport ] is a new transport that aims at improving   network performance by enabling out of order delivery, partial   reliability, and methods of recovery besides retransmission, while   also improving security.  This document specifies FEC schemes for   Sliding Window Random Linear Code (RLC) [ RLC] to recover from lost   packets within a single QUIC stream or across several QUIC streams,   compliant with the FEC coding framework for QUIC [ Coding4QUIC ].   The ability to add FEC coding in QUIC may be beneficial in several   situations:   o  for a robust transmission of latency sensitive traffic, for      instance real-time flows, since it enables to recover packet      losses independently of the round trip time;Roca, et al.            Expires December 23, 2018               [Page 2] Internet-Draft                RLC for QUIC                     June 2018   o  for the transmission of contents to a large set of QUIC reception      endpoints, since the same repair frame may help recovering several      different packet losses at different receivers;   o  for multipath communications, since repair traffic adds diversity.2.  Definitions and Abbreviations   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this   document are to be interpreted as described in [ RFC2119].   Terms and definitions that apply to coding are available in   [ nc-taxonomy ].  More specifically, this document uses the following   definitions:   Packet versus Symbol:  a Packet is the unit of data that is exchanged      over the network while a Symbol is the unit of data that is      manipulated during the encoding and decoding operations   Source Symbol:  a unit of data originating from the source that is      used as input to encoding operations   Repair Symbol:  a unit of data that is the result of a coding      operation   This document uses the following abbreviations:   E: size of an encoding symbol (i.e., source or repair symbol),      assumed fixed (in bytes)3.  Procedures   This section introduces the procedures that are used by these FEC   Schemes.3.1 .  Source Symbols Mapping   The present FEC Scheme follows the source symbols mapping specified   in [ Coding4QUIC ].  Figure 1 illustrates this mapping.Roca, et al.            Expires December 23, 2018               [Page 3] Internet-Draft                RLC for QUIC                     June 2018    < -E- > < -E- > < -E- > < -E- >   +-------+-------+-------+-------+   |< -- Frame 1 -- >< ----- Frame |  source symbols 0, 1, 2, 3   +-------+-------+-------+-------+   | 2 ----- >< --- Frame 3 -- >< -|  source symbols 4, 5, 6, 7   +-------+-------+----+--+-------+   | Frame 4 - >< -F5- >|             source symbols 8, 9 and 10   +-------+-------+----+             (incomplete)      Figure 1: Example of source symbol mapping, when the E value is                             relatively small.3.2 .  Pseudo-Random Number Generator (PRNG)   The RLC FEC Schemes defined in this document rely on the TinyMT32   PRNG defined in [ RLC].3.3 .  Coding Coefficients Generation Function   The coding coefficients, used during the encoding process, are   generated at the RLC encoder by the generate_coding_coefficients()   function each time a new repair symbol needs to be produced.  This   specification uses the generate_coding_coefficients() defined in   [ RLC].4.  Sliding Window RLC FEC Scheme over GF(2^^8) when Protecting a Single    QUIC Stream   This fully-specified FEC Scheme defines the Sliding Window Random   Linear Codes (RLC) over GF(2^^8) when protecting a single QUIC   stream.4.1 .  Formats and Codes4.1.1 .  Configuration Information   This section provides the RLC configuration information that needs to   be shared during QUIC negotiation between the QUIC sender and   receiver endpoints in order to synchronize them.   o  FEC Encoding ID: the value assigned to this fully specified FEC      Scheme MUST be XXXX, as assigned by IANA ( Section 7 ).  This FEC      Encoding ID is used during the QUIC negotiation to uniquely      identify the RLC FEC Scheme for QUIC;   o  Encoding symbol size, E (in bytes): a non-negative integer that      indicates the size of each source and repair symbol, in bytes.Roca, et al.            Expires December 23, 2018               [Page 4] Internet-Draft                RLC for QUIC                     June 2018      This element is required both by the QUIC sender endpoint (RLC      encoder) and the QUIC receiver endpoint(s) (RLC decoder).4.1.2 .  REPAIR Frame Format   The RLC FEC Scheme does not use any explicit Source FEC Payload ID,   meaning that QUIC STREAM frame format is not modified.   On the opposite, the RLC FEC Scheme requires QUIC REPAIR frames to   convey enough information.  This section specifies the REPAIR frame   format specific to the RLC FEC Scheme and a single QUIC stream.  Note   that the notion of REPAIR frame format is equivalent to the notion of   Repair FEC Payload ID in [ RLC].    0                   1                   2                   3    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                         Stream ID (i)                       ...   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |               [Offset of First Source Symbol in EW (i)]     ...   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                         [Length (i)]                        ...   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |       Repair_Key              |  DT   |NSS (# src symb in ew) |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |                        Stream Data                          ...   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    Figure 2: REPAIR frame format when protecting a single QUIC stream.   More precisely, the REPAIR frame format is composed of the following   fields (Figure 2):   Stream ID (variable-size field):  a variable-length integer      indicating the stream ID of the stream.  See [ QUIC-transport ].      The Stream ID for an RLC REPAIR frame MUST be equal to the Stream      ID used for the data stream it protects;   Offset of First Source Symbol in the Encoding Window (variable-size   field):      a variable-length integer specifying the byte offset in the stream      for the first source symbol of the encoding window.   Length (variable-size field):  a variable-length integer specifying      the length of the Stream Data field in this REPAIR frame.  This      length MUST be a non zero multiple of the source symbol size, E,      since a REPAIR frame contains one or more repair symbols for this      stream;Roca, et al.            Expires December 23, 2018               [Page 5] Internet-Draft                RLC for QUIC                     June 2018   Repair_Key (16-bit field):  this unsigned integer is used as a seed      by the coefficient generation function ( Section 3.3 ) in order to      generate the desired number of coding coefficients.  When a FEC      Repair Packet contains several repair symbols, this repair key      value is that of the first repair symbol.  The remaining repair      keys can be deduced by incrementing by 1 this value, up to a      maximum value of 65535 after which it loops back to 0.   Density Threshold for the coding coefficients, DT (4-bit field):      this unsigned integer carries the Density Threshold (DT) used by      the coding coefficient generation function Section 3.3 .  More      precisely, it controls the probability of having a non zero coding      coefficient, which equals (DT+1) / 16.  When a FEC Repair Packet      contains several repair symbols, the DT value applies to all of      them;   Number of Source Symbols in the encoding window, NSS (12-bit field):      this unsigned integer indicates the number of source symbols in      the encoding window when this repair symbol was generated.  When a      FEC Repair Packet contains several repair symbols, this NSS value      applies to all of them;   Stream Data:  data for this repair symbol(s).4.1.3 .  Additional Procedures4.2 .  FEC Code Specification   This RLC FEC Scheme relies on the FEC code specification defined in   [ RLC].4.2.1 .  Encoding Side   [RLC] high level description of a Sliding Window RLC encoder also   applies here to this FEC Scheme.4.2.2 .  Decoding Side   [RLC] high level description of a Sliding Window RLC decoder also   applies here to this FEC Scheme.5.  Sliding Window RLC FEC Scheme over GF(2^^8) when Protecting Several    QUIC Streams   This section focusses on the general case where FEC protection is   globally applied across two or more QUIC streams.Roca, et al.            Expires December 23, 2018               [Page 6] Internet-Draft                RLC for QUIC                     June 2018   TODO6.  Security Considerations   TBD7.  IANA Considerations   This document registers two values in the "QUIC FEC Encoding IDs"   registry as follows:   o  XXXX refers to the Sliding Window Random Linear Codes (RLC) over      GF(2^^8) FEC Scheme for a Single QUIC Stream, as defined in      Section 4  of this document.   o  YYYY refers to the Sliding Window Random Linear Codes (RLC) over      GF(2^^8) FEC Scheme for a Several QUIC Stream, as defined in      Section 5  of this document.8.  Acknowledgments   TBD9.  References9.1 .  Normative References   [Coding4QUIC]              Swett, I., Montpetit, M-J., and V. Roca, "Coding for              QUIC", Work in Progress, NWCRG draft-swett-nwcrg-coding-              for-quic  (Work in Progress), June 2018,              < https://tools.ietf.org/html/              draft-swett-nwcrg-coding-for-quic >.   [QUIC-transport]              Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based              Multiplexed and Secure Transport", draft-ietf-quic-              transport-12  (work in progress), May 2018,              < https://datatracker.ietf.org/doc/              draft-ietf-quic-transport/ >.   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate              Requirement Levels", BCP 14 , RFC 2119 ,              DOI 10.17487/RFC2119, March 1997,              < https://www.rfc-editor.org/info/rfc2119 >.Roca, et al.            Expires December 23, 2018               [Page 7] Internet-Draft                RLC for QUIC                     June 2018   [RLC]      Roca, V., "Sliding Window Random Linear Code (RLC) Forward              Erasure Correction (FEC) Scheme for FECFRAME", Work              in Progress, Transport Area Working Group (TSVWG) draft-              ietf-tsvwg-rlc-fec-scheme  (Work in Progress), May 2018,              < https://tools.ietf.org/html/              draft-ietf-tsvwg-rlc-fec-scheme >.9.2 .  Informative References   [nc-taxonomy]              Roca et al., V., "Taxonomy of Coding Techniques for              Efficient Network Communications", draft-irtf-nwcrg-              network-coding-taxonomy  (Work in Progress) (work in              progress), June 2018, < https://datatracker.ietf.org/doc/              draft-irtf-nwcrg-network-coding-taxonomy/ >.Authors’ Addresses   Vincent Roca   INRIA   Univ. Grenoble Alpes   France   Email: vincent.roca@inria.fr   Ian Swett   Google   Cambridge, MA   US   Email: ianswett@google.com   Marie-Jose Montpetit   Triangle Video   Boston, MA   US   Email: marie@mjmontpetit.comRoca, et al.            Expires December 23, 2018               [Page 8]

https://hal.inria.fr/hal-01919876/file/draft-roca-nwcrg-rlc-fec-scheme-for-quic-00.pdf

Sliding Window Random Linear Code (RLC) Forward Erasure Correction (FEC) Schemes for QUIC

Abstract

Similar works

Full text

Available Versions

HAL-Rennes 1

INRIA a CCSD electronic archive server