1、BRITISH STANDARD BS ISO/IEC 9314-7:1998 Information technology Fibre Distributed Data Interface (FDDI) Part 7: Physical layer protocol (PHY-2) ICS 35.100.10BSISO/IEC9314-7:1998 This British Standard, having been prepared under the directionof the DISC Board, waspublished under the authorityof the St
2、andards Committee and comes intoeffecton 15 December 1998 BSI 05-1999 ISBN 0 580 28400 X National foreword This British Standard reproduces verbatim ISO/IEC 9314-7:1998 and implements it as the UK national standard. The UK participation in its preparation was entrusted to Technical Committee IST/39,
3、 Interconnection of IT equipment, cabling; microprocessors, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor rel
4、ated international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document ma
5、y be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British
6、Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the ISO/IEC title page, pages ii to iv, pages 1 to 41
7、and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSISO/IEC9314-7:1998 BSI 05-1999 i Contents Page National
8、 foreword Inside front cover Foreword iv Text of ISO/IEC 9314-7 1ii blankBSISO/IEC9314-7:1998 ii BSI 05-1999 Contents Page Foreword iv Introduction 1 1 Scope 1 2 Normative references 3 3 Definitions 4 4 Conventions and abbreviations 7 4.1 Conventions 7 4.2 Abbreviations 8 5 General description 8 6 S
9、ervices 10 6.1 PHY-to-DLL services 10 6.1.1 PH_UNITDATA.request 10 6.1.2 PH_UNITDATA.indication 11 6.1.3 PH_INVALID.indication 11 6.2 PHY-to-PMD services 11 6.2.1 PM_UNITDATA.request 12 6.2.2 PM_UNITDATA.indication 12 6.2.3 PM_SlGNAL.indication 12 6.3 PHY-to-SMT services 13 6.3.1 SM_PH_LINE_STATE.re
10、quest 13 6.3.2 SM_PH_STATUS.indication 14 6.3.3 SM_PH_CONTROL.request 14 7 Facilities 16 7.1 Coding 16 7.1.1 Code bit 16 7.1.2 Code group 17 7.2 Symbol set 17 7.2.1 Line state symbols 17 7.2.2 Control symbols 17 7.2.3 Data Quartets (0-F) 18 7.2.4 Violation symbol (V) 19 7.3 Line states 19 7.3.1 Line
11、 State (QLS) 19 7.3.2 Halt Line State (HLS) 19 7.3.3 Master Line State (MLS) 19 7.3.4 Idle Line State (ILS) 19 7.3.5 Active Line State (ALS) 20 7.3.6 Cycle Line State (CLS) 20 7.3.7 Noise Line State (NLS) 20 8 Operation 22 8.1 General 22 8.1.1 Coding 22 8.1.2 Clocking 23 8.1.3 Latency 23 8.2 Encode
12、function 24 8.3 Transmit function 24 8.4 Receive function 24 8.5 Decode function 24 8.6 Elasticity Buffer function 25 8.7 Line State Detection function 27BSISO/IEC9314-7:1998 BSI 05-1999 iii Page 8.8 Smoothing function 28 8.8.1 Limit Smoother 29 8.8.2 Target Smoother 32 8.9 Repeat Filter function 35
13、 8.9.1 State RF0: IDLE 35 8.9.2 State RF1: REPEAT 36 8.9.3 State RF2: FILTER 36 Annex A (informative) Ring Latency Calculation 40 Figure 1 Structure of FDDI standards 3 Figure 2 Peer Physical Connection example 9 Figure 3 PHY functional block diagram example 21 Figure 4 Limit Smoother state diagram
14、30 Figure 5 Target Smoother state diagram 33 Figure 6 Repeat Filter state diagram 37 Figure 7 FDDI-II jitter characteristics 39 Table 1 Symbol coding 16BSISO/IEC9314-7:1998 iv BSI 05-1999 Foreword ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Co
15、mmission) form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity.
16、ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information technology, ISO and IEC have established a joint technical committee,
17、ISO/IEC JTC 1. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least75% of the national bodies casting a vote. International Standard ISO/IEC9314-7 was prepared by Jo
18、int Technical Committee ISO/IEC JTC 1 Information technology, Subcommittee SC 25, Interconnection of information technology equipment. ISO/IEC 9314 consists of the following parts, under the general title Information technology Fibre Distributed Data Interface (FDDI): Part 1: Token Ring Physical Lay
19、er Protocol (PHY) (1989); Part 2: Token Ring Media Access Control (MAC) (1989); Part 3: Physical Layer Medium Dependent (PMD) (1990); Part 4: Single Mode Fibre Physical Layer Medium Dependent (SMF-PMD) 1) ; Part 5: Hybrid Ring Control (HRC) (1995); Part 6: Station Management (SMT); Part 7: Physical
20、Layer Protocol (PHY-2); Part 8: Media Access Control-2 (MAC-2); Part 9: Low-Cost Fibre Physical Medium Dependent (LCF-PMD) (under consideration); Part 10: Token Ring Twisted Pair Physical layer Medium Dependent (TP-PMD) (under consideration); Part 13: Conformance Test Protocol Implementation Conform
21、ance Statement Proforma (CT-PICS); Part 20: Physical Medium Dependent Conformance Testing (PMD-ATS) (under consideration); Part 21: Physical Layer Protocol Conformance Testing (PHY-ATS) (under consideration); Part 25: Abstract Test Suite for FDDI- Station Management Conformance Testing (SMT-ATS); Pa
22、rt 26: Media Access Control Conformance Testing (MAC-ATS) (under consideration). 1) To be published.BSISO/IEC9314-7:1998 BSI 05-1999 1 Introduction The Fibre Distributed Data Interface (FDDI), ISO/IEC9314, is intended for use in a high-performance general purpose multi-node network and is designed f
23、or efficient operation with a peak data rate of100Mbit/s. It uses a Token Ring architecture with optical fibre as the transmission medium. FDDI provides for hundreds of nodes operating over an extent of tens of kilometers. The Physical Layer Protocol (PHY) specifies the upper sublayer of the Physica
24、l Layer for the FDDI. As such, it presents the specifications and services provided for conforming FDDI attachment devices. PHY specifies the data encode and decode, framing, and clocking requirements. PHY also specifies the elasticity buffer, smoothing, and repeat filter functions. When the set of
25、basic FDDI standards, ISO/IEC9314, is completed it will include the following standards: a) A Media Access Control (MAC), which specifies the lower sublayer of the Data Link Layer of ISO/IEC9314; b) A Physical Layer Media Dependent (PMD), which specifies the lower sublayer of the Physical Layer of I
26、SO/IEC9314; c) A Station Management (SMT), which specifies the local portion of the system management application process of ISO/IEC9314. A number of extensions to ISO/IEC9314 are completed or in process. One extension, ISO/IEC9314-5, for Hybrid Ring Control (HRC) commonly known as FDDI-II, extends
27、the capability of FDDI to handle isochronous data streams at a multiplicity of data rates. Another extension, ISO/IEC9314-4, provides for a single-mode optical fibre version of PMD (SMF-PMD) and will permit optical links of up60km. Other extensions, addressing alternate PMDs, provide low-cost attach
28、ments for use in concentrator-to-workstation environments. This part of ISO/IEC 9314 for PHY-2 is an enhancement to the original FDDI standard on PHY (ISO 9314-1). It is referred to as PHY-2 when it is necessary to distinguish it from the original PHY. Changes include those identified in footnotes t
29、o ISO9314-1 as areas that the standards committee intended to change as well as changes that were required for extensions to FDDI, such as FDDI-II. PHY-2 also includes editorial corrections and clarifications. 1 Scope This part of ISO/IEC9314 specifies the Physical Layer Protocol (PHY), the upper su
30、blayer of the Physical Layer, for Fibre Distributed Data Interface (FDDI). FDDI provides a high-bandwidth(100 Mbit/s), general-purpose interconnection among information processing systems, subsystems and peripheral equipment, using fibre optics or other transmission media. FDDI can be configured to
31、support a sustained data transfer rate of at least80Mbit/s (10 Mbyte/s). FDDI provides connectivity for many nodes distributed over distances of many kilometers in extent. Certain default parameter values for FDDI (e.g. timer settings) are calculated on the basis of up to1000 transmission links or u
32、p to200km total fibre-path length (typically corresponding to 500 nodes and100km of dual fibre cable, respectively); however, the FDDI protocols can support much larger networks by increasing these parameter values. As shown in Figure 1, FDDI consists of a) Physical Layer (PL), which is divided into
33、 two sublayers: 1) A Physical Medium Dependent (PMD), which provides the digital baseband point-to-point communication between nodes in the FDDI network. The PMD provides all services necessary to transport a suitably coded digital bit stream from node to node. The PMD defines and characterizes the
34、fibre-optic drivers and receivers, medium-dependent code requirements, cables, connectors, power budgets, optical bypass provisions, and physical-hardware-related characteristics. It specifies the point of interconnectability for conforming FDDI attachments. The initial PMD standard defines attachme
35、nt to multi-mode fibre. Alternative PMD sublayer standards are being developed for attachment to other transmission media and for mapping to Synchronous Optical Network (SONET),BSISO/IEC 9314-7:1998 2 BSI 05-1999 2) A Physical Layer Protocol (PHY), which provides connection between the PMD and the D
36、ata Link Layer. PHY establishes clock synchronization with the upstream code-bit data stream and decodes this incoming code-bit stream into an equivalent symbol stream for use by the higher layers. PHY provides encoding and decoding between data and control indicator symbols and code bits, medium co
37、nditioning and initializing, the synchronization of incoming and outgoing code-bit clocks, and the delineation of octet boundaries as required for the transmission of information to or from higher layers. Information to be transmitted on the medium is encoded by the PHY using a group transmission co
38、de. The definition of PHY is contained in this part of ISO/IEC 9314. b) A Data Link Layer (DLL), which is divided into two or more sublayers: 1) An optional Hybrid Ring Control (HRC), which provides multiplexing of packet and circuit switched data on the shared FDDI medium. HRC comprises two interna
39、l components, a Hybrid Multiplexer (H-MUX) and an Isochronous MAC (I-MAC). H-MUX maintains a synchronous125 4s cycle structure and multiplexes the packet and circuit switched data streams, and I-MAC provides access to circuit switched channels, 2) A Media Access Control (MAC), which provides fair an
40、d deterministic access to the medium, address recognition, and generation and verification of frame check sequences. Its primary function is the delivery of packet data, including frame generation, repetition, and removal, 3) An optional Logical Link Control (LLC), which provides a common protocol f
41、or any required packet data adaptation services between MAC and the Network Layer. LLC is not specified by FDDI, 4) An optional Circuit Switching Multiplexer (CS-MUX), which provides a common protocol for any required circuit data adaptation services between I-MAC and the Network Layer. CS-MUX is no
42、t specified by FDDI. c) A Station Management (SMT), which provides the coordination necessary at the node level to manage the processes under way in the various FDDI layers such that a node may work cooperatively on a ring. SMT provides services such as control of configuration management, fault iso
43、lation and recovery, and scheduling policies. The definition of PHY as contained in this part of ISO/IEC9314 is designed to be as independent as possible from the actual physical medium. This part of ISO/IEC9314 is an optional alternative to the original part of ISO/IEC9314 on PHY (ISO9314-1) for im
44、plementations without an (optional) HRC, and is required for implementations with an HRC. Implementations that conform to this part of ISO/IEC9314 shall also be interoperable with implementations that conform to ISO9314-1 if the additional capability of Hybrid mode operation (asdefined in this part
45、of ISO/IEC9314) is not being used. Implementers are encouraged to read ISO9314-1 in addition to this part of ISO/IEC9314. The set of FDDI standards specifies the interfaces, functions and operations necessary to ensure interoperability between conforming FDDI implementations. This part ofISO/IEC9314
46、 is a functional description. Conforming implementations may employ any design technique that is interoperable.BSISO/IEC9314-7:1998 BSI 05-1999 3 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO/IEC9314
47、. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISO/IEC9314 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Membersof IEC and I
48、SO maintain registers of currently valid International Standards. ISO 9314-1:1989, Information processing systems Fibre Distributed Data Interface (FDDI) Part1:Token Ring Physical Layer Protocol (PHY). ISO 9314-2:1989, Information processing systems Fibre Distributed Data Interface (FDDI) Part2:Toke
49、n Ring Media Access Control (MAC). ISO/IEC 9314-3:1990, Information processing systems Fibre Distributed Data Interface (FDDI) Part 3: Physical Layer Medium Dependent (PMD). Figure 1 Structure of FDDI standardsBSISO/IEC 9314-7:1998 4 BSI 05-1999 ISO/IEC 9314-4, Information technology Fibre Distributed Data Interface (FDDI) Part 4: Single Mode Fibre Physical Layer Medium Dependent (SMF-PMD) 2) . ISO/IEC 9314-5:1995, Information technology Fibre Distributed Data Interface (FDDI) Part 5: Hybrid Rin
