1、 International Telecommunication Union ITU-T J.112TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Annex B(03/2004) SERIES J: CABLE NETWORKS AND TRANSMISSION OF TELEVISION, SOUND PROGRAMME AND OTHER MULTIMEDIA SIGNALS Interactive systems for digital television distribution Transmission systems for in
2、teractive cable television services Annex B: Data-over-cable service interface specifications: Radio-frequency interface specification ITU-T Recommendation J.112 Annex B ITU-T Rec. J.112/Annex B (03/2004) i ITU-T Recommendation J.112 Transmission systems for interactive cable television services Ann
3、ex B Data-over-cable service interface specifications: Radio-frequency interface specification Summary Annex B defines the radio-frequency interface specifications for high-speed data-over-cable systems. There are two options for physical layer technology, which have equal priority and are not requi
4、red to be interoperable. One technology option is based on the downstream multi-programme television distribution that is deployed using 6 MHz channelling, and supports upstream transmission in the 5-42 MHz region. The second technology option is based on a multi-programme television distribution us
5、ing 8 MHz channel spacing and supports upstream in the 5-65 MHz region. Both options have equal status. The first of these options is defined in clauses B.4, B.6 and B.7, whereas the second is defined by replacing the content of those clauses with the content of Annex B.N. Annex B.O “Privacy for cab
6、le modem implementations“ to the former Annex B/J.112 is removed because it became the stand-alone ITU-T Rec. J.125. Source Annex B to ITU-T Recommendation J.112 was approved on 15 March 2004 by ITU-T Study Group 9 (2001-2004) under the ITU-T Recommendation A.8 procedure. ii ITU-T Rec. J.112/Annex B
7、 (03/2004) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff que
8、stions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendatio
9、ns on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation,
10、 the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or a
11、pplicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance wi
12、th the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or appl
13、icability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implemen
14、t this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. ITU 2005 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior w
15、ritten permission of ITU. ITU-T Rec. J.112/Annex B (03/2004) iii CONTENTS Page Annex B Data-over-cable service interface specifications: Radio-frequency interface specification 1 B.1 Scope and purpose 1 B.2 References 4 B.3 Definitions and abbreviations. 7 B.4 Functional assumptions 16 B.5 Communica
16、tion protocols 20 B.6 Physical media-dependent sublayer specification 29 B.7 Downstream transmission convergence sublayer. 53 B.8 Media access control specification. 56 B.9 Media access control protocol operation 119 B.10 Quality of Service another vendor may omit the same item. Other text is descri
17、ptive or explanatory. B.1.3 Background B.1.3.1 Service goals Cable operators are interested in deploying high-speed packet-based communications systems on cable television systems that are capable of supporting a wide variety of services. Services under consideration by cable operators include packe
18、t telephony service, videoconferencing service, T1/frame relay equivalent service, and many others. It has been decided to prepare a series of interface specifications that will permit the early definition, design, development and deployment of data-over-cable systems on a uniform, consistent, open,
19、 non-proprietary, multi-vendor interoperable basis. The intended service will allow transparent bidirectional transfer of Internet Protocol (IP) traffic, between the cable system headend and customer locations, over an all-coaxial or hybrid-fibre/coax (HFC) cable network. This is shown in simplified
20、 form in Figure B.1-1. Figure B.1-1/J.112 Transparent IP traffic through the data-over-cable system The transmission path over the cable system is realized at the headend by a Cable Modem Termination System (CMTS), and at each customer location by a Cable Modem (CM). At the headend (or hub), the int
21、erface to the data-over-cable system is called the Cable Modem Termination System Network-Side Interface (CMTS-NSI) and is specified in DOCSIS3. At the customer locations, the interface is called the cable-modem-to-customer-premises-equipment interface (CMCI) and is specified in DOCSIS4. The intent
22、is for operators to transparently transfer IP traffic between these interfaces, including but not limited to datagrams, DHCP, ICMP, and IP Group addressing (broadcast and multicast). B.1.3.2 Reference architecture The reference architecture for the data-over-cable services and interfaces is shown in
23、 Figure B.1-2. NOTE This architecture illustrates the North American frequency plans only and is not normative for European applications. Refer to B.1.1 for applicability. ITU-T Rec. J.112/Annex B (03/2004) 3 Figure B.1-2/J.112 Data-over-cable reference architecture B.1.3.3 Categories of interface s
24、pecification The basic reference architecture of Figure B.1-2 involves five categories of interface. Data Interfaces These are the CMCI DOCSIS4 and CMTS-NSI DOCSIS3, corresponding respectively to the cable-modem-to-customer-premises-equipment (CPE) interface (for example, between the customers compu
25、ter and the cable modem), and the cable modem termination system network-side interface between the cable modem termination system and the data network. Operations Support Systems Interfaces These are network element management layer interfaces between the network elements and the high-level OSSs (o
26、perations support systems) which support the basic business processes, and are documented in SCTE4. Telephone Return Interface CMTRI This is the interface between the cable modem and a telephone return path, for use in cases where the return path is not provided or not available via the cable networ
27、k, and is documented in DOCSIS6. RF Interfaces The RF interfaces defined in Annex B are the following: between the cable modem and the cable network; between the CMTS and the cable network, in the downstream direction (traffic toward the customer); between the CMTS and the cable network, in the upst
28、ream direction (traffic from the customer). Security interfaces Baseline data-over-cable security is defined in ITU-T J.125. 4 ITU-T Rec. J.112/Annex B (03/2004) B.1.3.3.1 Data-Over-Cable Service Interface documents A list of the documents in the Data-Over-Cable Service Interface Specifications fami
29、ly is provided below. For updates, please refer to URL http:/. Designation Title SP-CMCI Cable Modem to Customer Premises Equipment Interface Specification SP-CMTS-NSI Cable Modem Termination System Network Side Interface Specification SP-CMTRI Cable Modem Telco Return Interface Specification SP-OSS
30、I Operations Support System Interface Specification SP-RFI Radio Frequency Interface Specification SP-BPI+ Baseline Privacy Plus Interface Specification Key to designations SP Specification TP Test Plan A document of test procedures to validate specification conformance, interoperability or performa
31、nce TR Technical Report (provides a context for understanding and applying the specification or initial ideas about possible future features) B.1.3.4 Statement of compatibility This clause applies only to the first option as defined in B.1.1. Annex B specifies an interface, commonly referred to as D
32、OCSIS 1.1, which is an extension of the interface specified in SCTE1, commonly referred to as DOCSIS 1.0. These extensions are entirely backwards and forwards compatible with the previous version of Annex B/J.112. DOCSIS 1.1 compliant CMs MUST interoperate seamlessly with DOCSIS 1.0 CMTSs. DOCSIS 1.
33、1 compliant CMTSs MUST seamlessly support DOCSIS 1.0 CMs. Refer to Annex B.G for further interoperability information. B.2 References B.2.1 Normative references The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of
34、 Annex B. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this annex are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references liste
35、d below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this annex does not give it, as a stand-alone document, the status of a Recommendation. IEEE 802.1Q IEEE 802.1Q-2003, IEE Standard for Local and Metropolitan Area Networks: Virtual
36、 Bridged Local Area Networks. IEC 60169-24 IEC 60169-24 (1991-11), Radio-frequency connectors Part 24: Radio-frequency coaxial connectors with screw coupling, typically for use in 75 ohm cable distribution systems (Type F). ISO/IEC 8825-1 ITU-T Recommendation X.690 (2002) | ISO/IEC 8825-1:2002, Info
37、rmation technology ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER). ITU-T Rec. J.112/Annex B (03/2004) 5 ISO/IEC 8802-2 ISO/IEC 8802-2:1998 (IEEE Std 802.2:1998), Information technology Telecommunications and in
38、formation exchange between systems Local and metropolitan area networks Specific requirements Part 2: Logical link control. ISO/IEC 8802-3 ISO/IEC 8802-3:2000 (IEEE Std 802.3:2000), Information technology Telecommunications and information exchange between systems Local and metropolitan area network
39、s Part 3: Carrier sense multiple access with collision detection (CSMA/CD) access method and physical sublayer specifications. ISO/IEC 10038 ISO/IEC 10038:1993 (ANSI/IEEE Std 802.1D:1993), Information technology Telecommunications and information exchange between systems Local area networks Media ac
40、cess control (MAC) bridges. ISO/IEC 10039 ISO/IEC 10039:1991, Information technology Open Systems Interconnection Local area networks Medium Access Control (MAC) service definition. ITU-T H.222.0 ITU-T Recommendation H.222.0 (2000) | ISO/IEC 13818-1:2000, Information technology generic coding of mov
41、ing pictures and associated audio information: Systems. ITU-T J.83-B ITU-T Recommendation J.83 (1997) Annex B, Digital multi-programme systems for television, sound and data services for cable distribution. ITU-T J.125 ITU-T Recommendation J.125 (2004), Link privacy for cable modem implementations.
42、ITU-T X.25 ITU-T Recommendation X.25 (1996), Interface between data terminal equipment (DTE) and data circuit-terminating equipment (DCE) for terminals operating in the packet mode and connected to public data networks by dedicated circuit. RFC 791 IETF RFC 791 (1981), Internet Protocol. RFC 826 IET
43、F RFC 826 (1982), Ethernet Address Resolution Protocol: Or Converting Network Protocol Addresses to 48-bit Ethernet Address for Transmission on Ethernet hardware. RFC 868 IETF RFC 868 (1983), Time Protocol. RFC 1042 IETF RFC 1042 (1988), A standard for the Transmission of IP Datagrams over IEEE 802
44、Networks. RFC 1123 IETF RFC 1123 (1989), Requirements for Internet Hosts Application and Support. RFC 1157 IETF RFC 1157 (1990), A Simple Network Management Protocol (SNMP). RFC 1350 IETF RFC 1350 (1992), The TFTP Protocol (Revision 2). RFC 2104 IETF RFC 2104 (1997), HMAC: Keyed-Hashing For Message
45、Authentication. RFC 2131 IETF RFC 2131 (1997), Dynamic Host Configuration Protocol. RFC 2132 IETF RFC 2132 (1997), DHCP Options and BOOTP Vendor Extensions. RFC 2236 IETF RFC 2236 (1997), Internet Group Management Protocol, Version 2. RFC 2349 IETF RFC 2349 (1998), TFTP Timeout Interval And Transfer
46、 Size Options. RFC 2786 IETF RFC 2786 (2000), Diffie-Helman USM Key Management Information Base And Textual Convention. 6 ITU-T Rec. J.112/Annex B (03/2004) RFC 3046 IETF RFC 3046 (2001), DHCP Relay Agent Information Option. RFC 3256 IETF RFC 3256 (2002), The DOCSIS Device Class DHCP Relay Agent Inf
47、ormation Sub-Option. SCTE1 ANSI/SCTE 22-1 (2002), DOCSIS 1.0, Radio Frequency Interface. SCTE2 ANSI/SCTE 22-2 (2002), DOCSIS 1.0, Baseline Privacy Interface. SCTE4 ANSI/SCTE 23-3 (2003), DOCSIS 1.1 Part 3: Operations Support System Interface. SHA NIST, FIPS PUB 180-1 (1995), Secure Hash Standard. B.
48、2.2 Informative references CableLabs2 CableLabs2 (November 1994), Digital Transmission Characterization of Cable Television Systems, Cable Television Laboratories, Inc. DOCSIS3 Data-Over-Cable Service Interface Specifications, Cable Modem Termination System Network Side Interface Specification, SP-C
49、MTS-NSII01-960702. DOCSIS4 Data-Over-Cable Service Interface Specifications, Cable Modem to Customer Premises Equipment Interface Specification, SP-CMCI-I04-000714. DOCSIS6 Data-Over-Cable Service Interface Specifications, Cable Modem Telephony Return Interface Specification, SP-CMTRI-I01-970804. EIAS 542 EIA Standard 542 (1997), Cable Television Channel Identification Plan. EN 300 429 ETSI EN
