LOOPS Generic Information Set
draft-welzl-loops-gen-info-02

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TSVWG                                                           M. Welzl
Internet-Draft                                        University of Oslo
Intended status: Standards Track                         C. Bormann, Ed.
Expires: May 8, 2020                             Universitaet Bremen TZI
                                                       November 05, 2019

                     LOOPS Generic Information Set
                     draft-welzl-loops-gen-info-02

Abstract

   LOOPS (Local Optimizations on Path Segments) aims to provide local
   (not end-to-end but in-network) recovery of lost packets to achieve
   better data delivery in the presence of losses.
   [I-D.li-tsvwg-loops-problem-opportunities] provides an overview over
   the problems and optimization opportunities that LOOPS could address.

   The present document is a strawman for the set of information that
   would be interchanged in a LOOPS protocol, without already defining a
   specific data packet format.

   The generic information set needs to be mapped to a specific
   encapsulation protocol to actually run the LOOPS optimizations.  The
   current version of this document contains sketches of bindings to GUE
   [I-D.ietf-intarea-gue] and Geneve [I-D.ietf-nvo3-geneve].

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on May 8, 2020.

Welzl & Bormann            Expires May 8, 2020                  [Page 1]
Internet-Draft                    LOOPS                    November 2019

Copyright Notice

   Copyright (c) 2019 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
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   5
   2.  Challenges  . . . . . . . . . . . . . . . . . . . . . . . . .   6
     2.1.  No Access to End-to-End Transport Information . . . . . .   6
     2.2.  Path Asymmetry  . . . . . . . . . . . . . . . . . . . . .   6
     2.3.  Reordering vs. Spurious Retransmission  . . . . . . . . .   6
     2.4.  Informing the End-to-End Transport  . . . . . . . . . . .   7
     2.5.  Congestion Detection  . . . . . . . . . . . . . . . . . .   8
   3.  Simplifying assumptions . . . . . . . . . . . . . . . . . . .   8
   4.  LOOPS Generic Information Set . . . . . . . . . . . . . . . .   9
     4.1.  Setup Information . . . . . . . . . . . . . . . . . . . .   9
     4.2.  Forward Information . . . . . . . . . . . . . . . . . . .   9
     4.3.  Reverse Information . . . . . . . . . . . . . . . . . . .  10
   5.  LOOPS General Operation . . . . . . . . . . . . . . . . . . .  11
     5.1.  Initial Packet Sequence Number  . . . . . . . . . . . . .  11
       5.1.1.  Minimizing collisions . . . . . . . . . . . . . . . .  11
       5.1.2.  Optional Initial PSN procedure  . . . . . . . . . . .  12
     5.2.  Acknowledgement Generation  . . . . . . . . . . . . . . .  12
     5.3.  Measurement . . . . . . . . . . . . . . . . . . . . . . .  13
       5.3.1.  Ingress-relative timestamps . . . . . . . . . . . . .  13
       5.3.2.  ACK generation  . . . . . . . . . . . . . . . . . . .  14
     5.4.  Loss detection and Recovery . . . . . . . . . . . . . . .  14
       5.4.1.  Local Retransmission  . . . . . . . . . . . . . . . .  14
       5.4.2.  FEC . . . . . . . . . . . . . . . . . . . . . . . . .  15
     5.5.  Discussion  . . . . . . . . . . . . . . . . . . . . . . .  15
   6.  Sketches of Bindings to Tunnel Protocols  . . . . . . . . . .  15
     6.1.  Embedding LOOPS in Geneve . . . . . . . . . . . . . . . .  16
     6.2.  Embedding LOOPS in GUE  . . . . . . . . . . . . . . . . .  16
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  16
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  16