LOOPS (Localized Optimizations of Path Segments) Problem Statement and Opportunities
draft-li-tsvwg-loops-problem-opportunities-02

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TSVWG                                                              Y. Li
Internet-Draft                                                   X. Zhou
Intended status: Informational                                    Huawei
Expires: November 25, 2019                                  May 24, 2019

 LOOPS (Localized Optimizations of Path Segments) Problem Statement and
                             Opportunities
             draft-li-tsvwg-loops-problem-opportunities-02

Abstract

   In various network deployments, end to end paths are partitioned into
   multiple segments.  In some cloud based WAN connections, multiple
   overlay tunnels in series are used to achieve better path selection
   and lower latency.  In satellite communication, the end to end path
   is split into two terrestrial segments and a satellite segment.
   Packet losses can be caused both by random events or congestion in
   various deployments.

   Traditional end-to-end transport layers respond to packet loss slowly
   especially in long-haul networks: They either wait for some signal
   from the receiver to indicate a loss and then retransmit from the
   sender or rely on sender's timeout which is often quite long.  Non-
   congestion caused packet loss may make the TCP sender over-reduce the
   sending rate unnecessarily.  With end-to-end encryption moving under
   the transport (QUIC), traditional PEP (performance enhancing proxy)
   techniques such as TCP splitting are no longer applicable.

   LOOPS (Local Optimizations on Path Segments) aims to provide non end-
   to-end, locally based in-network recovery to achieve better data
   delivery by making packet loss recovery faster and by avoiding the
   senders over-reducing their sending rate.  In an overlay network
   scenario, LOOPS can be performed over the existing, or purposely
   created, overlay tunnel based path segments.

Status of This Memo

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Li & Zhou               Expires November 25, 2019               [Page 1]
Internet-Draft        LOOPS Problem & opportunities             May 2019

   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 November 25, 2019.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   4
   2.  Cloud-Internet Overlay Network  . . . . . . . . . . . . . . .   5
     2.1.  Tail Loss or Loss in Short Flows  . . . . . . . . . . . .   7
     2.2.  Packet Loss in Real Time Media Streams  . . . . . . . . .   8
     2.3.  Packet Loss and Congestion Control in Bulk Data Transfer    8
     2.4.  Multipathing  . . . . . . . . . . . . . . . . . . . . . .   9
   3.  Satellite Communication . . . . . . . . . . . . . . . . . . .   9
   4.  Features and Impacts to be Considered for LOOPS . . . . . . .  11
     4.1.  Local Recovery and End-to-end Retransmission  . . . . . .  12
       4.1.1.  OE to OE Measurement, Recovery and Multipathing . . .  13
     4.2.  Congestion Control Interaction  . . . . . . . . . . . . .  14
     4.3.  Overlay Protocol Extensions . . . . . . . . . . . . . . .  16
     4.4.  Summary . . . . . . . . . . . . . . . . . . . . . . . . .  16
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  17
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  17
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  17
   8.  Informative References  . . . . . . . . . . . . . . . . . . .  17
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  19

1.  Introduction

   Overlay tunnels are widely deployed for various networks, including
   long haul WAN interconnection, enterprise wireless access networks,
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