IPWAVE Working Group                                              K. Sun
Internet-Draft                                                    Y. Kim
Intended status: Informational                       Soongsil University
Expires: April 18, 2021                                 October 15, 2020


   Considerations for ID/Location Separation Protocols in IPv6-based
                           Vehicular Networks
                draft-kjsun-ipwave-id-loc-separation-03

Abstract

   ID/Location separation protocols are proposed for scalable routing,
   enhancing mobility and privacy in IPv6-based vehicular networks.  In
   IPv6-based vehicular networks, ID/Location separation architecture is
   expected to offer benefits.  This document analyzes how ID/Location
   separation protocols can adjust into IP based vehicular networks and
   suggests requirements for efficient ID/Location separation in
   vehicular networks.

Status of This Memo

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   This Internet-Draft will expire on April 18, 2021.

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   include Simplified BSD License text as described in Section 4.e of
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Vehicular Network Architecture with ID/Location Separation  .   3
   4.  Gap Analysis  . . . . . . . . . . . . . . . . . . . . . . . .   4
     4.1.  Neighbor Discovery  . . . . . . . . . . . . . . . . . . .   4
     4.2.  Mobility Management . . . . . . . . . . . . . . . . . . .   5
     4.3.  Security and Privacy  . . . . . . . . . . . . . . . . . .   6
   5.  Acknkowledgement  . . . . . . . . . . . . . . . . . . . . . .   6
   6.  Informative References  . . . . . . . . . . . . . . . . . . .   6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   8

1.  Introduction

   For vehicular networks, it is required to provide connection to the
   Intelligent Transport Systems (ITS) for the driver's safety,
   efficient driving and entertainment with fast mobility management.
   Other scenarios besides V2I communication, like V2V and V2X
   communication are also considered.  Link layer protocols such as IEEE
   802.11-OCB [IEEE-802.11-OCB] are already defined for low-latency and
   alternative networks, and it is designed for enabling IPv6 as a
   network layer protocol.  Nevertheless, for using IPv6 in the
   vehicular network, there are some requirements for optimization as
   described in [ietf-ipwave-vehicular-networking].  These issues are
   classified into IPv6 neighbor discovery, mobility management,
   security and privacy.

   In IETF, there are two major ID/Location separation protocols such as
   LISP [RFC6830] and ILNP [RFC6740] for scalable routing, enhancing
   privacy and mobility management.  Currently ID/Location separation
   concept is useful not only for decomposing ID/Location from an IP
   address, but also for control/data plane separation which is a major
   evolution of the Internet infrastructure.  For the vehicular
   networks, ID/Location separation protocols can be expected to meet
   requirements and solve problem statements discussed in IPWAVE WG.
   This document describes use cases for applying ID/Location separation
   architecture to IPv6-based vehicular networks, and analyzes how such
   protocols can meet requirements for IPv6 in vehicular networks.








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2.  Terminology

   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].  This
   document uses the terminology described in
   [ietf-ipwave-vehicular-networking], [RFC6830], [RFC6740].

3.  Vehicular Network Architecture with ID/Location Separation

                     Traffic Control Center in Vehicular Cloud
                    *******************************************
+-------------+    *                                           *
|Corresponding|   *             +-----------------+             *
|    Node     |<->*             |   ID/Location   |             *
+-------------+   *             |  Mapping System |             *
                  *             +--------^--------+             *
                  *                      |                      *
                   *                     v                     *
                    *******************************************
                    ^                   ^                     ^
                    |                   |                     |
                    |                   |                     |
                    v                   v                     v
              +----------+         +----------+         +----------+
              | LOC-RSU1 |<------->| LOC-RSU2 |<------->| LOC-RSU3 |
              +----------+         +----------+         +----------+
                  ^                     ^                    ^
                  :                     :                    :
              +-----------------+ +-----------------+   +-----------------+
              |      : V2I      | |        : V2I    |   |       : V2I     |
              |      v          | |        v        |   |       v         |
+-----------+ |   +-----------+ | |  +-----------+  |   | +-----------+   |
|ID-Vehicle1|===> |ID-Vehicle2|===>  |ID-Vehicle3|===>  | |ID-Vehicle4|==>|
+-----------+<...>+-----------+<....>+-----------+  |   | +-----------+   |
              V2V     ^         V2V        ^        |   |        ^        |
              |       : V2V     | |        : V2V    |   |        : V2V    |
              |       v         | |        v        |   |        v        |
              |   +-----------+ | |  +-----------+  |   | +-----------+   |
              |   |ID-Vehicle5|===>  |ID-Vehicle6|===>  | |ID-Vehicle7|==>|
              |   +-----------+ | |  +-----------+  |   | +-----------+   |
              +-----------------+ +-----------------+   +-----------------+
                   LOC site1           LOC site2              LOC site3

           <----> Wired Link   <....> Wireless Link   ===> Moving Direction

   Figure 1: Vehicular Network Architecture with ID/Location Separation




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   Figure 1 shows a conceptional architecture of vehicular networks with
   ID/Location Separation.  All components in the architecture can be
   mapped with components defined in [ietf-ipwave-vehicular-networking].
   For ID, fixed values which is similar IP address are assigned to all
   network interfaces of vehicle.  In the case of LISP [RFC6830], a
   128-bit value which is the full length of IPv6 address can be defined
   as unique End-Point IDs (EIDs), which can communicate with other EIDs
   in the same LISP site same as a legacy IPv6 operation.  On the other
   hand, ILNPv6 [RFC6740] uses just a 64-bit value in the IPv6 address
   field as an Identifier.

   Since each RSU can represent the location of vehicles that are
   connected to the network, they can be defined as a locator.  For
   LISP, which is a network-based approach, LISP router functions can be
   implemented inside of RSU.  In the case of ILNPv6, as same as ID, the
   locator is configured in 64-bit length in the IPv6 address field and
   it can be represented subnet of each RSU.  That is, in the ILNPv6,
   the general IPv6 address value is replaced with an Identifier-Locator
   Vector (I-LV) allowing it to be applied to the current IPv6 header
   without modification.

   In ID/Location separation architectures, managing mapping information
   of ID and its allocated locator is necessary.  With the mapping
   system, the corresponding node which is located external network or
   even inside the vehicular network can get the current location of the
   vehicle ID to communicate with and configure the routing path.  Also,
   instead of the mobility anchor, the mapping system can support the
   mobility management of vehicles by updating the location value of ID
   according to changes in their location.  The mapping system can be
   implemented in different ways depending on the protocol.  For
   example, ILNPv6 defines new DNS resource record type for mapping I-LV
   values.  A DNS server deployed in the vehicular cloud is accessible
   from both in ILNP site and the external Internet.

4.  Gap Analysis

4.1.  Neighbor Discovery

   In both cases of LISP and ILNP, the usage of the existing neighbor
   discovery message defined in [RFC4861] is possible without
   modification.  In LISP, Vehicles and RSUs in the same LISP site can
   exchange ND/NA messages for routing by EID configured as IPv6 format.
   Also, ILNP can operate the neighbor discovery for the configuration
   of an I-LV value as the I-LV for ILNPv6 occupies the same bits as the
   IPv6 address in the IPv6 header[RFC6740].  Thus, for vehicular
   networking, it is expected that the same solutions already mentioned
   in [ietf-ipwave-vehicular-networking] (e.g., new ND option




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   [ID-Vehicular-ND]) can also be applicable in the ID/Location
   separation architecture.

4.2.  Mobility Management

   One of the advantages for using LISP is that mobility management can
   be provided efficiently, when a device is roaming across different
   LISP sites while maintaining its EID.  The existing IP mobility
   management schemes such as MIP or PMIP require an anchor function
   (e.g., Home Agent and Local Mobility Anchor) to maintain the IP
   address of a mobile node when the mobile node moves.  They can
   construct a non-optimized forwarding path between the anchor and
   current attachment point of the mobile node.  In LISP, however, a
   forwarding path can be optimized by updating EID-RLOC mapping
   information and establishing an IP tunnel between the xTR of the
   corresponding node and the xTR of the current mobile node's
   attachment point.  This provides advantages for easily optimizing a
   forwarding path especially the vehicular networks where the
   connection point of the mobile node can be move fast away from its
   initial attachment point.  In the vehicular networks, a vehicle with
   an EID will roam much faster and it means that the mapped RLOC will
   be changed more frequently.  For faster RLOC assignment, a predictive
   RLOC algorithm for roaming-EID is proposed in LISP WG
   [draft-ietf-lisp-predictive-rlocs].  Using this algorithm, it
   predicts the moving direction of a vehicle with a roaming-EID,
   registers predictive RLOCs as a list to the mapping system, and
   replicates packets to each RLOC in the list.  It can minimize packet
   loss while maintaining transport session continuity.

   In ILNP, mobility management is classified into host mobility and
   network (or site) mobility.  For vehicular networks, host mobility
   scenario is suitable [RFC6740].  When the vehicle moves to its
   network attachment point and locator, it shortly becomes to belong to
   a new site, it may send a Locator Update (LU) message to the
   Corresponding Node (CN) and also send a request to the DNS server to
   change its entry.  Even though LU procedure is necessary, it causes
   delay and packet loss during handover, and it may become a more
   critical issue in the vehicular networks where the locator of a
   vehicle is updated faster and more frequently.  Therefore, ILNP needs
   to minimize LU process including DNS updates for seamless mobility
   management in vehicular networks.  For example,
   [ILNP-Sol-Wireless-Net] may be one possible solution that defines a
   geological information server, which gives information of attachment
   points nearby to devices to prepare handover, deliver its predictive
   locator to the CN so that it can reduce packet loss and latency for
   updating DNS.





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4.3.  Security and Privacy

   For supporting applications such as autonomous driving, the vehicular
   networks require not only low latency and high bandwidth but also a
   high level of security and privacy.  The IPWAVE working group is
   facing a mobility management challenge due to latency and management
   complexity due to the exchange of signaling messages with mobility
   anchor to establish a tunnel.  In the ID/Location separation
   approach, all vehicles maintain their unique ID while they are
   allocated a locator in the fastest way without binding update
   procedure.  Nevertheless, a privacy problem still exists due to the
   easy access to the mapping system.  Even though it is difficult to
   track a device using a single RLOC or locator value since its locator
   changes while moving across sites, on the other hand, since an EID or
   identifier is defined as permanent, additional methodologies need to
   be considered to secure device identifier information.

   Another consideration is various communication links.  In the
   vehicular networks, not only V2I communication but also V2X
   communication are required.  It means that vehicles can directly
   communicate with each other only with an ID value without a locator
   which is allocated from the infrastructure.  In this scenario, the
   exposure of vehicle IDs to others (including hackers) occurs
   frequently even though they do not access mapping system.  In
   [draft-iannone-pidloc-privacy], they describe about privacy issues
   and requirements in ID/Location separation architecture.

   Several existing works can provide enhanced privacy mechanisms in ID/
   Location separation architectures.  For example,
   [draft-ietf-lisp-eid-anonymity] defines Ephemeral-EID which is
   frequently changed by the device.  For ILNP, identity privacy
   supports using IPv6 privacy extensions for stateless address auto-
   configuration [RFC4941] and Locator Rewriting Relay (LRR) component
   for locator privacy [RFC6748], can be solutions for enhancing privacy
   in vehicular networks.

5.  Acknkowledgement

   We would like to thank Jahoon Paul Jeong as a contributor who
   reviewed and gave comments for this version.

6.  Informative References

   [draft-iannone-pidloc-privacy]
              Iannone, L., von Hugo, D., Sarikaya, B., and E. Nordmark,
              "Privacy issues in Identifier/Locator Separation Systems",
              draft-iannone-pidloc-privacy-00 (working on progress)
              (work in progress), January 2020.



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   [draft-ietf-lisp-eid-anonymity]
              Farinacci, D., Pillay-Esnault, P., and W. Haddad, "LISP
              EID Anonymity", draft-ietf-lisp-eid-anonymity-07(working
              on progress) (work in progress), October 2019.

   [draft-ietf-lisp-predictive-rlocs]
              Farinacci, D. and P. Pillay-Esnault, "LISP Predictive
              RLOCs", draft-ietf-lisp-predictive-rlocs-05(working on
              progress) (work in progress), November 2019.

   [ID-Vehicular-ND]
              Jeong, J., Shen, Y., and Z. Xiang, "Vehicular Neighbor
              Discovery for IP-Based Vehicular Network", draft-jeong-
              ipwave-vehicular-neighbor-discovery-08(working on
              progress) (work in progress), November 2019.

   [IEEE-802.11-OCB]
              "Part 11: Wireless LAN Medium Access Control (MAC) and
              Physical Layer (PHY) Specifications",  IEEE Std
              802.11-2016, December 2016.

   [ietf-ipwave-vehicular-networking]
              Jeong, J., "IP Wireless Access in Vehicular Environments
              (IPWAVE): Problem Statement and Use Cases", draft-ietf-
              ipwave-vehicular-networking-13(working on progress) (work
              in progress), January 2020.

   [ILNP-Sol-Wireless-Net]
              Isah, M. and CJ. Edwards, "An ILNP-based solution for
              future heterogeneous wireless networks", PGNET
              2013: Proceedings of the 14th Annual Postgraduate
              Symposium on the Convergence of Telecommunications,
              Networking and Broadcasting, June 2013.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", RFC 2119, March 1997.

   [RFC4861]  Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
              "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
              September 2007.

   [RFC4941]  Narten, T., Draves, R., and S. Krishnan, "Privacy
              Extensions for Stateless Address Autoconfiguration in
              IPv6", RFC 4941, September 2007.

   [RFC6740]  Atkinson, RJ., Bhatti, SN., and U. St Andrews,
              "Identifier-Locator Network Protocol (ILNP) Architectural
              Description", RFC 6740, November 2012.



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   [RFC6741]  Atkinson, RJ., Bhatti, SN., and U. St Andrews,
              "Identifier-Locator Network Protocol (ILNP) Engineering
              Considerations", RFC 6741, November 2012.

   [RFC6748]  Atkinson, RJ., Bhatti, SN., and U. St Andrews, "Optional
              Advanced Deployment Scenarios for the Identifier-Locator
              Network Protocol (ILNP)", RFC 6748, November 2012.

   [RFC6830]  Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, "The
              Locator/ID Separation Protocol (LISP)", RFC 6830, January
              2013.

Authors' Addresses

   Kyoungjae Sun
   School of Electronic Engineering
   Soongsil University
   369, Sangdo-ro, Dongjak-gu
   Seoul, Seoul  06978
   Republic of Korea

   Phone: +82 10 3643 5627
   EMail: gomjae@dcn.ssu.ac.kr


   Younghan Kim
   School of Electronic Engineering
   Soongsil University
   369, Sangdo-ro, Dongjak-gu
   Seoul, Seoul  06978
   Republic of Korea

   Phone: +82 10 2691 0904
   EMail: younghak@ssu.ac.kr

















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