1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 29281-1:2013Intelligent transport systems Communication access forland mobiles (CALM) Non-IPnetworkingPart 1: Fast networking 35.240.60Compliance with a British Standard c
2、annot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 April 2013.Amendments issued since publicationDate T e x t a f f e c t e dBS ISO 29281-1:2013 ISO 2013Intelligent transport systems Communication ac
3、cess for land mobiles (CALM) Non-IP networking Part 1: Fast networking protocol extensions for N-hop groupcast; LPP; secured communication; ITS station-internal forwarding of packets between ITS-S host ITS-SCUs and ITS-S router ITS-SCUs.FNTP is validated in the CVIS project. ISO 2013 All rights rese
4、rved vBS ISO 29281-1:2013BS ISO 29281-1:2013Intelligent transport systems Communication access for land mobiles (CALM) Non-IP networking Part 1: Fast networking Communications Access for Land Mobiles (CALM); Test specifications for non-IP networking (ISO 29281); Part 1: Protocol implementation confo
5、rmance “statement (PICS) proformaETSI TS 102 985-2, Intelligent Transport Systems (ITS); Communications Access for Land Mobiles (CALM); Test specifications for non-IP networking (ISO 29281); Part 2: Test suite structure Communications Access for Land Mobiles (CALM); Test specifications for non-IP ne
6、tworking (ISO 29281); Part 3: Abstract test suite and partial PIXIT (ATS) specificationINTERNATIONAL STANDARD ISO 29281-1:2013(E) ISO 2013 All rights reserved 1BS ISO 29281-1:2013ISO 29281-1:2013(E)3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 21217
7、, ISO 24102-3, ISO 24102-4 and the following apply.3.1ITS-S portsource and/or destination “endpoint” for communications identified by an integer number4 Abbreviated termsFNTP Fast networking and supports the concept of ITS station communication units (ITS-SCU) to implement roles of an ITS-S in physi
8、cal units specified (see ISO 21217, ISO 24102-1, ISO 24102-3 and ISO 24102-4).FNTP is primarily designed to enable single-hop communication between peer ITS stations with minimum protocol overhead, and supports optional features.NOTE ISO 15628 legacy systems support specified in 2 makes use of FNTP.
9、FNTP supports any kind of ad hoc access technology, e.g. CALM M5, CALM IR. FNTP may be used to connect source and destination “endpoints” identified by “ITS-S port” (ITS-SP) numbers in peer ITS stations, where peer ITS stations are uniquely identified by a Link-ID (usually MAC address contained in i
10、t) of the access layer specified in ISO 21218. Consequently, FNTP is a port mapper protocol, usually located in the transport layer of the OSI model.5.1.2 Basic mode of operationThe basic mode of operation is the simplest option of FNTP, which is just providing single-hop communications between inst
11、ances of ITS stations without applying any of the options of FNTP.5.1.3 Extended mode of operationThe extended mode of operation supports options of the FNTP, e.g.: ITS station-internal forwarding; secure communications; N-hop broadcast; LPP support; CIP management.2 ISO 2013 All rights reservedBS I
12、SO 29281-1:2013ISO 29281-1:2013(E)ITS station-internal forwarding is a special option referred to as “station-internal forwarding mode of operation”.Other options may be added in a future revision of this part of ISO 29281.5.2 FNTP reference architectureFigure 1 illustrates the location of FNTP in t
13、he ITS station (ITS-S) specified in ISO 21217, and the communication relations with other protocol entities.CommunicationsITS-S Networking extended mode of operation.The “FNTP Control” field value allows distinguishing details of these two modes of operation as specified in Table 2. The FNTP control
14、 field is a one octet bit-field as specified in Table 2.The basic mode of operation is indicated by the value zero in the “FNTP Control” field. In this case, the FNTP NPDU is referred to as “FNTP basic NPDU” in this part of ISO 29281.In the extended mode of operation, at least one “Option” field is
15、present. Bit B7 indicates presence or absence of the first optional element following the FNTP control field; Bit B6 indicates presence or absence of the second optional element following the FNTP control field; and so on; Bit B0 indicates presence or absence of the last optional element following t
16、he FNTP control field. Presence of an optional element shall be indicated by a value 1b in the respective bit field.Reserved bits shall be set to the value 0.8 ISO 2013 All rights reservedBS ISO 29281-1:2013ISO 29281-1:2013(E)Table 2 “FNTP Control” field (implemented as OPTION selector in ASN.1)B7 B
17、6 B5 B4 B3 B2 B1 B0 Description0 0 0 0 0 0 0 0 Used in the NF-FNTP-COMM service to indicate, that no extension is to be applied.1 no valueno valueno valueno valueno valueno valueno valueOption 0: ITS station-internal forwarding. The related Options field is present.no value1 no valueno valueno value
18、no valueno valueno valueOption 1: Support of secure communications. The related Options field is present.no valueno value1 no valueno valueno valueno valueno valueOption 2: N-hop broadcast. The related Options field is present.no valueno valueno value1 no valueno valueno valueno valueOption 3: So fa
19、r undefined feature. The related Options field is of ASN.1 NULL type. Reserved for future.no valueno valueno valueno value1 no valueno valueno valueOption 4: So far undefined feature. The related Options field is of ASN.1 NULL type. Reserved for future.no valueno valueno valueno valueno value1 no va
20、lueno valueOption 5: So far undefined feature. The related Options field is of ASN.1 NULL type. Reserved for future.no valueno valueno valueno valueno valueno value1 no valueOption 6: LPP support. The related Options field is present.no valueno valueno valueno valueno valueno valueno value1 Option 7
21、: CIP support. The related Options field is present.An FNTP NPDU with “FNTP Control” field containing a value different to 00000000b is referred to as “FNTP extended NPDU” in this International Standard.6.2.2.3.2 ITS station-internal forwardingIn order to forward an FNTP NPDU station-internally betw
22、een an ITS-S host and an ITS-S router or vice versa, the FNTP header shall contain values as specified in Table 3.Table 3 FNTP header values for station-internal forwardingForwarding direction sourcePort field destinationPort fieldFrom FNTP management in ITS-S router to FNTP management in ITS-S host
23、PORT_RTR PORT_HSTFrom FNTP management in ITS-S host to FNTP management in ITS-S routerPORT_HST PORT_RTRThe FNTP Options field for station-internal forwarding shall be as illustrated in Figure 7.“Options“ for station-internal forwardingITS-SCU-IDITS-S hostLink-ID VCI inITS-S routerCountersourcePortPo
24、rtNumberdestinationPortPortNumberFigure 7 FNTP header Options field for station-internal forwardingASN.1 details of the FNTP header Options field for station-internal forwarding illustrated in Figure 7 shall be as specified in Annex A.The format of ITS-SCU-ID shall be as specified in ISO 24102-1. Th
25、e format of Link-ID shall be as specified in ISO 21218. ISO 2013 All rights reserved 9BS ISO 29281-1:2013ISO 29281-1:2013(E)The field “Counter” shall contain a cyclic packet counter being unique in the source ITS-SCU. The size of this field shall be one octet as specified in Annex A.The fields sourc
26、ePort and destinationPort contain the port numbers used in the link between the peer ITS stations.An FNTP NPDU for ITS station-internal forwarding is referred to as “FNTP forwarding NPDU” in this part of ISO 29281.6.2.2.3.3 Secure communicationsThe FNTP Options field in support of secure communicati
27、ons shall be as illustrated in Figure 8.“Options“ in support of secure communicationsLength Security elementsFigure 8 FNTP header Options field in support of secure communicationsDetails of secure communications are not specified in this version of this part of ISO 29281.ASN.1 details of the FNTP he
28、ader Options field in support of secure communications illustrated in Figure 8 shall be as specified in Annex A.6.2.2.3.4 N-hop broadcastThe FNTP Options field for N-hop broadcast shall be as illustrated in Figure 9.“Options“ for N-hop broadcastFNTP hop countFigure 9 FNTP header Options field for N-
29、hop broadcastASN.1 details of the FNTP header Options field for N-hop broadcast illustrated in Figure 9 shall be as specified in Annex A.The FNTP hop count indicates to the receiving ITS station the number of allowed subsequent hops.6.2.2.3.5 LPP supportThe related Options field shall contain the LP
30、P header as specified in 1.6.2.2.3.6 CIP managementThe FNTP Options field for CIP management shall be as illustrated in Figure 10.“Options“ for CIP managementRX Length RX CIPs TX Length TX CIPsFigure 10 FNTP header Options field for CIP managementThe RX Length field indicates the length in octets of
31、 the RX CIPs field. The TX Length field indicates the length in octets of the TX CIPs field. At least either RX CIPs or TX CIPS shall be present. Details of CIPs 10 ISO 2013 All rights reservedBS ISO 29281-1:2013ISO 29281-1:2013(E)depend on the ITS-S access technology selected for communications and
32、 are outside the scope of this part of ISO 29281.ASN.1 details of the FNTP header Options field for CIP management illustrated in Figure 10 shall be as specified in Annex A.6.2.3 FNTP bodyThe FNTP body field shall contain an ITS-FPDU specified in ISO 21217 as illustrated in Figure 11.FNTP bodyITS-FP
33、DUFigure 11 FNTP body for basic mode of operation6.3 Protocol management elements6.3.1 Service look-up tableThe FNTP shall maintain look-up information as illustrated in Figure 12.ServiceService PortPortNumberITS-SCU-IDITS-S hostITS-S routerLink PortPortNumberService PriorityFigure 12 Service look-u
34、p table“Link Port” shall contain the port number used in the FNTP header in the link to a peer station or in the ITS station-internal network link, pointing indirectly to the ITS-SP of the service in the ITS-S host. “Service Port” shall contain the port number which points directly to the ITS-SP of
35、the service in the ITS-S host.NOTE 1 The value in “Service Port” thus is not necessarily disclosed to the peer entity. In case ITS-S host and ITS-S router functionality is implemented in the same ITS-SCU, “Link Port” and “Service Port” may have the same value, and the look-up information becomes obs
36、olete.“ITS-SCU-ID” shall identify the ITS-SCU of the ITS-S host where the service resides. “Service Priority” shall contain the maximum allowed user priority of the service.NOTE 2 The term “service” used in this context means protocol functionality in the ITS-S facilities layer addressable by an ITS
37、-SP number, which is using the communication service offered by an ITS-S networking and transport layer protocol, i.e. the FNTP.This look-up information is part of the information contained in forwarding tables specified in 6.3.2.6.3.2 Forwarding tableThe FNTP shall maintain information as illustrat
38、ed in Figure 13 needed to perform the protocol procedures specified in this part of ISO 29281. ISO 2013 All rights reserved 11BS ISO 29281-1:2013ISO 29281-1:2013(E)REMOTE LOCALITS-S host TimeoutLink PortPortNumberServiceITS-S routerInformation how to reach a remote port (either in peer ITS-S or peer
39、 ITS-SCU)CI StatusLink-ID User PriorityLink PortPortNumberService PortPortNumberITS-SCU-ID Service PriorityFigure 13 Forwarding tableThe elements below “REMOTE” allow accessing an ITS-SP in a peer ITS station or in a peer ITS-SCU of the same ITS-S. The elements in column “Link Port” shall carry the
40、port numbers as used in the communication link. A “Link Port” is unique only in combination with the corresponding “Link-ID”. The element “Link-ID” specified in ISO 21218 shall carry the Link-ID of the VCI which connects to the peer entity via the communication link. The element “CI Status” shall co
41、ntain the CI status specified in ISO 21218.NOTE 1 In case of ITS-S internal forwarding of FNTP NPDUs, Link Port is either PORT_HST or PORT_RTR, and Link-ID points to a BC-VCI which connects to the ITS station-internal network.The elements below “LOCAL” allow accessing an ITS-SP in the local entity.
42、The elements in column “Link Port” shall carry the port number as used in the link identifying the local ITS-SP to be used for a potential reply by the peer station. A “Link Port” is unique only at the local ITS-SCU containing the ITS-S router functionality.NOTE 2 The two elements “Link Port” thus a
43、re the sourcePort and destinationPort port numbers used in the link between peer entities (ITS-Ss or ITS-SCUs), i.e. in the header shown in Figure 6. The element “Service” shall be as specified in 6.3. The element “Priority” shall contain the user priority as specified in ISO 21218 to be used for co
44、mmunications. The value of “Priority” for an unknown priority shall be zero. The maximum value of “Priority” shall be as given in “Service Priority” of the service look-up table.NOTE 3 In case of ITS-S internal forwarding of FNTP NPDUs, Link Port is either PORT_HST or PORT_RTR, and Link-ID identifie
45、s the access technology which connects to the ITS station-internal network.The elements in column “Timeout” contain time information on the validity of this entry. The value of “Timeout” is given by implementation.12 ISO 2013 All rights reservedBS ISO 29281-1:2013ISO 29281-1:2013(E)7 Protocol proced
46、ures7.1 Service access points7.1.1 GeneralAs SAPs per definition describe a functional behaviour only, SAPs may be implemented in different ways. Requirements set up in this part of ISO 29281 to support SAPs and the related service primitives thus mean to support the functionality. This support may
47、be implemented either in a strict meaning, i.e. using the ASN.1 definitions of the service primitives as “PDU” definitions, or in an abstract meaning, allowing for proprietary solutions.7.1.2 IN-SAPThe FNTP shall interact with the ITS-S access layer specified in ISO 21217 using services of the IN-SA
48、P specified in ISO 21218.The FNTP shall support the IN-UNITDATA service of the IN-SAP specified in ISO 21218.The FNTP may use the IN-UNITDATA-STATUS service of the IN-SAP. The IN-UNITDATA-STATUS service is specified in ISO 21218.NOTE Usage of the information given by the IN-UNITDATA-STATUS service i
49、s not specified in this part of ISO 29281.7.1.3 NF-SAPThe FNTP shall interact with the ITS-S facilities layer specified in ISO 21217 offering services of the NF-SAP specified in this part of ISO 29181.The FNTP shall provide the NF-FNTP-PORT service and the NF-FNTP-COMM service of the NF-SAP specified in this part of ISO 29281.7.1.4 MN-SAPThe FNTP shall interact with the ITS-S management entity specified in ISO 21217 using services of the MN-SAP specified in ISO 24102-3.7.1.
