idnits 2.17.1 draft-yan-ipwave-nd-03.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** The document seems to lack an IANA Considerations section. (See Section 2.2 of https://www.ietf.org/id-info/checklist for how to handle the case when there are no actions for IANA.) ** The abstract seems to contain references ([RFC6762], [RFC6763]), which it shouldn't. Please replace those with straight textual mentions of the documents in question. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (October 15, 2018) is 1982 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Unused Reference: 'RFC2119' is defined on line 247, but no explicit reference was found in the text ** Obsolete normative reference: RFC 6106 (Obsoleted by RFC 8106) == Outdated reference: A later version (-17) exists of draft-jeong-ipwave-iot-dns-autoconf-03 Summary: 3 errors (**), 0 flaws (~~), 3 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group Z. Yan 3 Internet-Draft CNNIC 4 Intended status: Standards Track J. Lee 5 Expires: April 18, 2019 Sangmyung University 6 October 15, 2018 8 Service and Neighbor Discovery in ITS 9 draft-yan-ipwave-nd-03.txt 11 Abstract 13 For C-ACC, platooning and other typical use cases in ITS, direct IP 14 communication between neighbor vehicles poses the following two 15 issues: 1) how to discover the neighbor vehicle and the demanded 16 service; and 2) how to discover the link-layer address of the 17 neighbor vehicle and selected server. This draft presents a solution 18 to these problems based on DNS-SD/mDNS [RFC6762][RFC6763]. 20 Requirements Language 22 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 23 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 24 document are to be interpreted as described in RFC 2119. 26 Status of This Memo 28 This Internet-Draft is submitted in full conformance with the 29 provisions of BCP 78 and BCP 79. 31 Internet-Drafts are working documents of the Internet Engineering 32 Task Force (IETF). Note that other groups may also distribute 33 working documents as Internet-Drafts. The list of current Internet- 34 Drafts is at https://datatracker.ietf.org/drafts/current/. 36 Internet-Drafts are draft documents valid for a maximum of six months 37 and may be updated, replaced, or obsoleted by other documents at any 38 time. It is inappropriate to use Internet-Drafts as reference 39 material or to cite them other than as "work in progress." 41 This Internet-Draft will expire on April 18, 2019. 43 Copyright Notice 45 Copyright (c) 2018 IETF Trust and the persons identified as the 46 document authors. All rights reserved. 48 This document is subject to BCP 78 and the IETF Trust's Legal 49 Provisions Relating to IETF Documents 50 (https://trustee.ietf.org/license-info) in effect on the date of 51 publication of this document. Please review these documents 52 carefully, as they describe your rights and restrictions with respect 53 to this document. Code Components extracted from this document must 54 include Simplified BSD License text as described in Section 4.e of 55 the Trust Legal Provisions and are provided without warranty as 56 described in the Simplified BSD License. 58 Table of Contents 60 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 61 2. Prefix management . . . . . . . . . . . . . . . . . . . . . . 3 62 3. Name configuration . . . . . . . . . . . . . . . . . . . . . 3 63 4. Address configuration . . . . . . . . . . . . . . . . . . . . 4 64 5. Neighbor vehicle and service discovery . . . . . . . . . . . 4 65 6. Mobility support . . . . . . . . . . . . . . . . . . . . . . 5 66 7. Signaling messages . . . . . . . . . . . . . . . . . . . . . 5 67 8. Security considerations . . . . . . . . . . . . . . . . . . . 6 68 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 6 69 9.1. Normative References . . . . . . . . . . . . . . . . . . 6 70 9.2. Informative References . . . . . . . . . . . . . . . . . 6 71 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7 73 1. Introduction 75 As illustrated in [DNS-Autoconf], a naming scheme is needed for the 76 vehicle devices to support the unique name auto-configuration. This 77 can support the location based communicaton and scalable information 78 organization in ITS. Based on the naming scheme like this and the 79 widely-used DNS-SD/mDNS protocol, this draft illustrates how to 80 discover the neighbor vehicle or services with DNS resolution logic. 81 Before this, we make the following assumptions: 83 o Name: vehicle SHOULD have a temporary name which is related to its 84 geo-location. 86 o Address: vehicle SHOULD have a global IP address which is 87 routeable for the IP communications. 89 In this way, a standardized, efficient and scalable scheme can be 90 used to retrieve the necessary information of the corresponding node 91 (domain name, IP address, goe-location, link-local address and so on) 92 for the further communications based on the DNS-SD/mDNS function. In 93 addition, the extended NDP messages (e.g., RA and RS messages) can 94 also be used to exchange some required information (e.g., mobile 95 network prefixes, link-local address) in ITS in combination with DNS- 96 SD/mDNS [MNPP]. 98 2. Prefix management 100 The network architecture which illustrates the prefix management of 101 name and address is shown in Figure 1. 103 +------------+ +**********+ +------------+ 104 | Router1 |--------* Internet *--------| Router2 | 105 |[IP-Prefix1]| +**********+ |[IP-Prefix2]| 106 +------------+ +------------+ 107 | | 108 | | 109 ----------- ----------- 110 | | | | 111 | | | | 112 +-------+ +-------+ +-------+ +-------+ 113 | RSU1 | | RSU2 | | RSU3 | | RSU4 | 114 |[Name1]| |[Name2]| |[Name3]| |[Name4]| 115 +-------+ +-------+ +-------+ +-------+ 117 +-------+ 118 |Vehicle|--------moving----------> 119 +-------+ 121 Figure 1: Name and address management architecture 123 As shown in Figure 1, Router1 and Router2 are two routers which can 124 connect to the Internet and they hold different IP prefixes. RSU1 125 and RSU2 are two RSUs under Router1 but hold different name prefixes, 126 while RSU3 and RSU4 are two RSUs under Router2 but hold different 127 name prefixes. 129 3. Name configuration 131 The RSU acts as an access router for the static and moving vehicles 132 which want to be connected. Based on [RFC3640], [RFC6106] or 133 extended WSA message, the RSU can announce its location based name 134 prefix to the vehicles covered by the RSU. This location based 135 prefix may contain information such as country, city, street and so 136 on, which will act as the "domain_name" of the vehicle device name as 137 spefified in [DNS-Autoconf]. 139 4. Address configuration 141 The RSU may advertise the IP prefix to support the SLAAC operation of 142 vehicle devices and movement detection (in the IP layer). If the 143 DHCP is used for the address configuration, RSU also acts as 144 functional entity of the DHCP infrastructure . 146 5. Neighbor vehicle and service discovery 148 (1) RSU based 150 Vehicles may have direct connection with the serving RSU and join the 151 same link with the serving RSU. Then the RSU can maintain the 152 registered vehicle or service in its serving domain. Otherwise, the 153 RSU acts as a relay node for discovering in a proxy manner. 155 When a vehicle wants to locate the potential nearby neighbor and 156 further establish the communication, the vehicle will trigger the 157 direct unicast query to port 5353 or legacy unicast DNS query to the 158 RSU. RSU may respond directly if it has the related information, 159 otherwise, the RSU multicasts the DNS query to multicast group to 160 retrieve the related information. Unicast response is the first 161 recommendation here because it can suppress the flooding, but of 162 course, the DNS response message can also be multicasted as an active 163 announcement of the verhicle or service existence. 165 (2) Ad-hoc based 167 Vehicles may communicate with each other or sense the front and rear 168 neighbors with DSRC, WiFi, blue-tooth or other short-distance 169 communication technologies, connecting each other in the Ad-hoc 170 manner. Then the discovery can be executed in an infrastructure-less 171 manner with the following phases, as specified in mDNS. 173 o Probing: When a vehicle starts up, wakes up from stalls or the 174 VANET topology changes (after configuration of the name and 175 address), it should probe the availability of the service it 176 announced. Then the vehicle periodically announces the service 177 and its existence with unsolicited multicast DNS response 178 containing, in the Answer Section, all of its service,name,address 179 and other information. The vehicle also updates the related 180 information actively if there is any change. 182 o Discovering: To support the service and neighbor vehicle discovery 183 in the dynamic and fragmentation-possible environment in VANET, 184 different query modes of mDNS can be used for different scenarios: 185 1) One-Short Multicast DNS Query can be used to locate a specific 186 vehicle (for example). 2) Continuous Multicast DNS Query can be 187 used to locate the nearby vehicles which are moving (for example). 189 o Refreshing: After the neighbor discovery illustrated above, the 190 vehicles should continually exchange their name, IP address, geo- 191 location and other information in order to refresh the established 192 communications. For example, the Multiple Questions Multicast 193 Responses can be used to update the caches of receivers 194 efficiently and Multiple Questions Unicast Responses can be used 195 to support the fast bootstrapping when new vehicle joins. 197 o Goodbye: When the vehicle arrives at its destination, stalls 198 temporarily or shuts down its communication or sensing devices, it 199 will announce the service suspending and its inexistence with 200 unsolicited multicast DNS response packet, giving the same RRs 201 (for example containing its name and address), but TTL of zero. 203 6. Mobility support 205 During the movement of the vehicle, it may cross different RUSes. 206 When attaching into a new RSU, the new domain prefix and new IP 207 prefix may be learned. Generally, there are two main cases for the 208 mobility: 210 o Name prefix changes and IP prefix remains, as shown in Figure 1, 211 the vehicle hands over from RSU1 to RSU2. The vehicle will 212 configure a new name from RSU2 and may update the new name in the 213 local database (e.g., RSU). But the vehicle should keep its 214 previous name for a period until that all the communicating 215 neighbors have learned its new name. During this period, the 216 vehicle will contain both previous and new names in the DNS 217 response message. 219 o Both name and IP prefixes change, as shown in Figure 1, the 220 vehicle hands over from RSU2 to RSU3. The vehicle will configure 221 both new name and new IP address from RSU3 and update them in the 222 local database. Then the above scheme can also be used or with 223 IP-layer mobility management protocols. 225 7. Signaling messages 227 To facilitate the further communication, the link-layer address and 228 geo-information may be included in the DNS message in a piggyback 229 manner. Otherwise, these information may be obtained through the 230 following NDP or other procedures. 232 8. Security considerations 234 In order to reduce the DNS traffic on the wireless link and avoid the 235 unnecessary flooding, the related schemes in mDNS can be used, such 236 as: Known-Answer Suppression, Multipacket Known-Answer Suppression, 237 Duplicate Question Suppression and Duplicate Answer Suppression. 239 In order to guarantee the origination of the DNS message and avoid 240 the DNS message tampering, the security consideration in mDNS should 241 also be adopted. 243 9. References 245 9.1. Normative References 247 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 248 Requirement Levels", BCP 14, RFC 2119, 249 DOI 10.17487/RFC2119, March 1997, 250 . 252 [RFC3640] van der Meer, J., Mackie, D., Swaminathan, V., Singer, D., 253 and P. Gentric, "RTP Payload Format for Transport of 254 MPEG-4 Elementary Streams", RFC 3640, 255 DOI 10.17487/RFC3640, November 2003, 256 . 258 [RFC6106] Jeong, J., Park, S., Beloeil, L., and S. Madanapalli, 259 "IPv6 Router Advertisement Options for DNS Configuration", 260 RFC 6106, DOI 10.17487/RFC6106, November 2010, 261 . 263 [RFC6762] Cheshire, S. and M. Krochmal, "Multicast DNS", RFC 6762, 264 DOI 10.17487/RFC6762, February 2013, 265 . 267 [RFC6763] Cheshire, S. and M. Krochmal, "DNS-Based Service 268 Discovery", RFC 6763, DOI 10.17487/RFC6763, February 2013, 269 . 271 9.2. Informative References 273 [DNS-Autoconf] 274 Jeong, J., Lee, S., and J. Park, "DNS Name 275 Autoconfiguration for Internet of Things Devices", draft- 276 jeong-ipwave-iot-dns-autoconf-03, July 2018. 278 [MNPP] Lee, J., Tsukada, M., and T. Ernst, "Mobile Network Prefix 279 Provisioning", draft-jhlee-mext-mnpp-00, October 2009. 281 Authors' Addresses 283 Zhiwei Yan 284 CNNIC 285 No.4 South 4th Street, Zhongguancun 286 Beijing 100190 287 China 289 EMail: yan@cnnic.cn 291 Jong-Hyouk Lee 292 Sangmyung University 293 31, Sangmyeongdae-gil, Dongnam-gu 294 Cheonan 295 Republic of Korea 297 EMail: jonghyouk@smu.ac.kr