IPWAVE Working Group Z. Yan
Internet-Draft CNNIC
Intended status: Standards Track J. Lee
Expires: May 20, 2020 Sangmyung University
J. Jeong
Sungkyunkwan University
November 17, 2019
Neighbor Vehicle Discovery and Service in IP-Based Vehicular Networks
draft-yan-ipwave-nd-05.txt
Abstract
For Cooperative Adaptive Cruise Control (C-ACC), platooning and other
typical use cases in ITS, direct IP communication between neighbor
vehicles poses the following two issues: 1) how to discover a
neighbor vehicle and the demanded service; and 2) how to discover the
link-layer address of the neighbor vehicle and selected server. This
document presents a solution to these problems based on DNS-SD/mDNS
[RFC6762][RFC6763].
Requirements Language
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 RFC 2119.
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
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Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on May 20, 2020.
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Copyright Notice
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document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Prefix management . . . . . . . . . . . . . . . . . . . . . . 3
3. Name configuration . . . . . . . . . . . . . . . . . . . . . 3
4. Address configuration . . . . . . . . . . . . . . . . . . . . 4
5. Neighbor vehicle and service discovery . . . . . . . . . . . 4
6. Mobility support . . . . . . . . . . . . . . . . . . . . . . 5
7. Signaling messages . . . . . . . . . . . . . . . . . . . . . 6
8. Security considerations . . . . . . . . . . . . . . . . . . . 6
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
9.1. Normative References . . . . . . . . . . . . . . . . . . 6
9.2. Informative References . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
As illustrated in [DNS-Autoconf], a naming scheme is needed for the
vehicle devices to support the unique name auto-configuration. This
can support the location based communicaton and scalable information
organization in Intelligent Transportation Systems (ITS). Based on
the naming scheme like this and the widely-used DNS-SD/mDNS protocol,
this document illustrates how to discover a neighbor vehicle or the
required services with DNS resolution logic. Before this, we make
the following assumptions:
o Name: A vehicle SHOULD have a temporary name which is related to
its geo-location.
o Address: A vehicle SHOULD have a global IP address which is
routeable for the IP communications.
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In this way, a standardized, efficient and scalable scheme can be
used to retrieve the necessary information of the corresponding node
(domain name, IP address, goe-location, link-local address and so on)
for the further communications based on the DNS-SD/mDNS function. In
addition, the IPv6 Neighbor Discovery (ND)'s messages (e.g., RA and
RS messages) can also be used to exchange some required information
(e.g., mobile network prefixes and link-local address) in ITS in
combination with DNS-SD/mDNS [MNPP].
2. Prefix management
The network architecture which illustrates the prefix management of
name and address is shown in Figure 1.
+------------+ +**********+ +------------+
| Router1 |--------* Internet *--------| Router2 |
|[IP-Prefix1]| +**********+ |[IP-Prefix2]|
+------------+ +------------+
| |
| |
----------- -----------
| | | |
| | | |
+-------+ +-------+ +-------+ +-------+
| RSU1 | | RSU2 | | RSU3 | | RSU4 |
|[Name1]| |[Name2]| |[Name3]| |[Name4]|
+-------+ +-------+ +-------+ +-------+
+-------+
|Vehicle|--------moving---------->
+-------+
Figure 1: Name and address management architecture
As shown in Figure 1, Router1 and Router2 are two routers which can
connect to the Internet and they hold different IP prefixes. RSU1
and RSU2 are two Road-Side Units (RSUs) under Router1 but hold
different name prefixes, while RSU3 and RSU4 are two RSUs under
Router2 but hold different name prefixes.
3. Name configuration
The RSU acts as an access router for the static and moving vehicles
which want to be connected with the Internet. Based on [RFC3646],
[RFC6106] or extended WAVE Service Announcement (WSA) message, the
RSU can announce its location based name prefix to the vehicles
covered by the RSU. This location based prefix may contain
information such as country, city, street and so on, which will act
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as the "domain_name" of the vehicle device name as spefified in [DNS-
Autoconf].
4. Address configuration
The RSU may advertise the IP prefix to support the IPv6 Stateless
Address Autoconfiguration (SLAAC) operation of vehicle devices and
movement detection (in the IP layer). If the DHCP is used for the
address configuration, RSU also acts as functional entity such as a
DHCP proxy and DHCP server.
5. Neighbor vehicle and service discovery
(1) RSU based
Vehicles may have direct connection with the serving RSU and join the
same link with the serving RSU. Then the RSU can maintain the
registered vehicle or service in its serving domain. Otherwise, the
RSU acts as a relay node for discovering in a proxy manner.
When a vehicle wants to locate the potential nearby neighbor and
further establish the communication, the vehicle will trigger the
direct unicast query to port 5353 or legacy unicast DNS query to the
RSU. RSU may respond directly if it has the related information,
otherwise, the RSU multicasts the DNS query to the multicast group to
retrieve the related information. A unicast response is the first
recommendation here because it can suppress the flooding, but of
course, the DNS response message can also be multicasted as an active
announcement of the verhicle or service existence.
(2) Ad-hoc based
Vehicles may communicate with each other or sense the front and rear
neighbor vehicles with DSRC, WiFi, Bluetooth or other short-distance
communication technologies, connecting each other in the Ad-hoc
manner. Then the discovery can be executed in an infrastructure-less
manner with the following phases, as specified in mDNS.
o Probing: When a vehicle starts up, wakes up from sleeping mode or
the Vehicular Ad Hoc Networks (VANET) topology changes (after
configuration of the name and address), it should probe the
availability of the service with which it can provide other
vehicles. Then the vehicle periodically announces the service and
its existence with unsolicited multicast DNS response containing,
in the Answer Section, all of its service name, DNS name, IP
address and other information. The vehicle also updates the
related information actively if there is any change.
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o Discovering: To support the service and neighbor vehicle discovery
in the dynamic and fragmentation-possible environment in VANET,
different query modes of mDNS can be used for different scenarios:
1) One-Short Multicast DNS Query can be used to locate a specific
vehicle. 2) Continuous Multicast DNS Query can be used to locate
the nearby vehicles which are moving.
o Refreshing: After the neighbor discovery as illustrated above, the
vehicles should continually exchange their DNS name, IP address,
geo-location and other information in order to refresh the
established communications. For example, the Multiple Questions
Multicast Responses can be used to update the caches of receivers
efficiently and Multiple Questions Unicast Responses can be used
to support the fast bootstrapping when a new vehicle joins.
o Goodbye: When the vehicle arrives at its destination, stops
temporarily or shuts down its communication or sensing devices, it
will announce the service suspending and its inexistence with an
unsolicited multicast DNS response packet, giving the same
Resource Records (RRs) (containing its DNS name and IP address),
but with zero Time-To-Live (TTL).
6. Mobility support
During the movement of the vehicle, it may cross different RSUs.
When a vehicle enters the communication coverage of a new RSU, the
new domain prefix and new IP prefix may be learned. Generally, there
are two main cases for the mobility:
o The domain name changes and the IP prefix remains, as shown in
Figure 1, the vehicle moves from the coverage of RSU1 to the
coverage of RSU2. The vehicle will configure a new DNS name from
RSU2 and may update the new DNS name in the local database (e.g.,
RSU). But the vehicle should keep its previous DNS name for a
while until that all the communicating neighbors have learned its
new DNS name. During this duration, the vehicle will contain both
the previous and new DNS names in the DNS response message.
o Both the domain name and IP prefix change, as shown in Figure 1,
the vehicle performs a handover from RSU2 to RSU3. The vehicle
will configure both its new DNS name and new IP address from RSU3
and update them in the local database. Then the above scheme can
also be used or with IP-layer mobility management protocols (e.g.,
Mobile IPv6 [RFC6275] and Proxy Mobile IPv6 [RFC5213]).
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7. Signaling messages
To facilitate the further communication, the link-layer address and
geo-information may be included in the DNS message in a piggyback
manner. Otherwise, this information may be obtained through the
following IPv6 Neighbor Discovery Protocol (NDP) or other procedures
(e.g., DHCP and WSA).
8. Security considerations
In order to reduce the DNS traffic on the wireless link and avoid the
unnecessary flooding, the related schemes in mDNS can be used, such
as: Known-Answer Suppression, Multipacket Known-Answer Suppression,
Duplicate Question Suppression and Duplicate Answer Suppression.
In order to guarantee the origination of the DNS message and avoid
the DNS message tampering, the security consideration in mDNS should
also be adopted.
9. References
9.1. Normative References
[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>.
[RFC3646] Droms, R., Ed., "DNS Configuration options for Dynamic
Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3646,
DOI 10.17487/RFC3646, December 2003,
<https://www.rfc-editor.org/info/rfc3646>.
[RFC5213] Gundavelli, S., Ed., Leung, K., Devarapalli, V.,
Chowdhury, K., and B. Patil, "Proxy Mobile IPv6",
RFC 5213, DOI 10.17487/RFC5213, August 2008,
<https://www.rfc-editor.org/info/rfc5213>.
[RFC6106] Jeong, J., Park, S., Beloeil, L., and S. Madanapalli,
"IPv6 Router Advertisement Options for DNS Configuration",
RFC 6106, DOI 10.17487/RFC6106, November 2010,
<https://www.rfc-editor.org/info/rfc6106>.
[RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility
Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July
2011, <https://www.rfc-editor.org/info/rfc6275>.
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[RFC6762] Cheshire, S. and M. Krochmal, "Multicast DNS", RFC 6762,
DOI 10.17487/RFC6762, February 2013,
<https://www.rfc-editor.org/info/rfc6762>.
[RFC6763] Cheshire, S. and M. Krochmal, "DNS-Based Service
Discovery", RFC 6763, DOI 10.17487/RFC6763, February 2013,
<https://www.rfc-editor.org/info/rfc6763>.
9.2. Informative References
[DNS-Autoconf]
Jeong, J., Lee, S., and J. Park, "DNS Name
Autoconfiguration for Internet-of-Things Devices in IP-
Based Vehicular Networks", draft-jeong-ipwave-iot-dns-
autoconf-07, November 2019.
[MNPP] Lee, J., Tsukada, M., and T. Ernst, "Mobile Network Prefix
Provisioning", draft-jhlee-mext-mnpp-00, October 2009.
Authors' Addresses
Zhiwei Yan
CNNIC
No.4 South 4th Street, Zhongguancun
Beijing 100190
China
EMail: yan@cnnic.cn
Jong-Hyouk Lee
Sangmyung University
31, Sangmyeongdae-gil, Dongnam-gu
Cheonan
Republic of Korea
EMail: jonghyouk@smu.ac.kr
Jaehoon Paul Jeong
Department of Computer Science and Engineering
Sungkyunkwan University
2066 Seobu-Ro, Jangan-Gu
Suwon, Gyeonggi-Do
Republic of Korea
EMail: pauljeong@skku.edu
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