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1、ANSI INCITS 248-1996 (R2001) (formerly ANSI X3.248-1996 (R2001) for Information Technology Fibre Distributed Data Interface (FDDI) Abstract Test Suite for FDDI Physical Layer Protocol Conformance Testing (PHY ATS) Copyright American National Standards Institute Provided by IHS under license with ANS
2、I Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 22:19:00 MDTNo reproduction or networking permitted without license from IHS -,-,- American National Standard Approval of an American National Standard requires review by ANSI that the requirements for due process, co
3、nsensus, and other criteria for approval have been met by the standards developer. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a
4、simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be made toward their resolution. The use of American National Standards is completely voluntary; their existence does not in any respect preclude anyone, whethe
5、r he has approved the standards or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standards. The American National Standards Institute does not develop standards and will in no circumstances give an interpretation of any American Nat
6、ional Standard. Moreover, no person shall have the right or authority to issue an interpretation of an American National Standard in the name of the American National Standards Institute. Requests for interpretations should be addressed to the secretariat or sponsor whose name appears on the title p
7、age of this standard. CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards Institute require that action be taken periodically to reaffirm, revise, or withdraw this standard. Purchasers of American National Standar
8、ds may receive current information on all standards by calling or writing the American National Standards Institute. CAUTION: The developers of this standard have requested that holders of patents that may be required for the implementation of the standard disclose such patents to the publisher. How
9、ever, neither the developers nor the publisher have undertaken a patent search in order to identify which, if any, patents may apply to this standard. As of the date of publication of this standard and following calls for the identification of patents that may be required for the implementation of t
10、he standard, no such claims have been made. No further patent search is conducted by the developer or publisher in respect to any standard it processes. No representation is made or implied that licenses are not required to avoid infringement in the use of this standard. Published by American Nation
11、al Standards Institute 11 West 42nd Street, New York, New York 10036 Copyright 1996 by Information Technology Industry Council (ITI) All rights reserved. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without prior written permission of ITI
12、, 1250 Eye Street NW, Washington, DC 20005. Printed in the United States of America Copyright American National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 22:19:00 MDTNo reproduction or networking permi
13、tted without license from IHS -,-,- ANSI X3.248-1996 American National Standard for Information Technology Fibre Distributed Data Interface (FDDI) Abstract Test Suite for FDDI Physical Layer Protocol Conformance Testing (PHY ATS) Secretariat Information Technology Industry Council Approved March 22,
14、 1996 American National Standards Institute, Inc. Abstract Conformance tests are specified to test the Physical Layer Protocol (PHY) function of an FDDI path. FDDI is a set of standards that defines a 100-Mbps token ring architecture and uses fibre optics as the transmission medium over distances of
15、 several km in extent. Copyright American National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 22:19:00 MDTNo reproduction or networking permitted without license from IHS -,-,- ii Foreword.iii 1Scope 1
16、2Normative references .1 3Definitions1 4Conventions and abbreviations.2 5Specification breakdown.2 6General5 6.1Path establishment.5 6.2Test environment6 6.3Measurement error.6 7Internal clock test .7 7.1Purpose .7 7.2Equipment7 7.3Configuration7 7.4Procedure 7 7.5Pass_fail criteria.7 8Repeating tes
17、ts 8 8.1General Test Setup 8 8.2Code symbols and line states .9 8.3Symbol Sequence Notation.10 8.4Symbol repetition test.11 8.5Clock recovery and elasticity buffer.11 8.6Smoothing buffer 13 8.7Path Delay .13 8.8Repeat filter .15 Tables 1Specification breakdown.3 2FDDI code symbol notation.10 Figures
18、 1FDDI Repeat Path and PHY functions.4 2Paths in a Dual attachment station6 3Internal clock test setup7 4Configuration for repeating tests.9 5Delay calibration setup .14 Contents Page Copyright American National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Fac
19、ility Yokosuka/9961031100 Not for Resale, 05/08/2007 22:19:00 MDTNo reproduction or networking permitted without license from IHS -,-,- iii Foreword (This foreword is not part of American National Standard X3.248-1996.) The Fibre Distributed Data Interface (FDDI) is intended for use in a high- perfo
20、rmance general-purpose multi-station network and is designed for effi- cient operation with a peak data rate of 100 Mbit/s. It uses a Token Ring Architecture with optical fiber as the transmission medium. FDDI provides for hundreds of stations operating over an extent of tens of kilometers. FDDI Phy
21、sical Layer Protocol (PHY) specifies the upper sublayer of the Physical Layer for the FDDI, including the data encode/decode, framing and clocking, as well as the elasticity buffer, smoothing and repeat filter functions. This Abstract Test Suite (ATS) provides a conformance test for FDDI PHY. FDDI P
22、HY, however, does contain several state machines and implements a protocol at the level of FDDI code symbols. The only physi- cal quantity that must be measured in this conformance test is frequency. The PHY ATS cannot use the Tree and Tabular Combined Notation (TTCN) language specified in ISO 7496
23、and a notation is developed in the PHY ATS for specifying test patterns and expected results in terms of FDDI code symbol strings. Four other standards, when available, will provide a complete confor- mance test of an FDDI station: NOTE The ATS MAC, ATS SMT, and PICS Proforma standards are under dev
24、elopment. a) An ATS for FDDI Physical Medium Dependent (PMD) that provides a conformance test for FDDI PMD. PMD specifies the optical interface of FDDI stations. PMD is not a protocol standard and this ATS requires the measurement of physical quantities such as optical power, wavelength, and signal
25、jitter. The PMD ATS differs from the methodology of higher- level protocol conformance tests written using the TTCN, because the TTCN notation does not provide a suitable vehicle for Physical Layer testing, where there is no concept of a protocol data unit and where phys- ical quantities must be mea
26、sured. (This standard is currently available as an American National Standard and is designated ANSI X3.255-1996.) b) An ATS for FDDI Media Access Control (MAC) that provides a confor- mance test for FDDI MAC. MAC specifies the lower sublayer of the Data Link Layer for FDDI. It specifies access to t
27、he medium, including addressing, data checking, and data framing. MAC also specifies the receiver and transmitter state machines. Since MAC is a protocol that deals primarily with complete PDUs, the TTCN language is used to specify MAC protocol tests. Provisions of MAC, however, require high- resolu
28、tion timing that may be difficult to achieve in commercial protocol testers. c) An ATS for FDDI Station Management (SMT) that provides a confor- mance test for FDDI SMT. SMT specifies the local portion of the system management application process for FDDI, including the control required for proper o
29、peration of an FDDI station in an FDDI ring. SMT provides services such as connection management, station insertion and removal, station initialization, configuration management and fault recovery, com- munications protocol for external authority, scheduling policies, and the collection of statistic
30、s. SMT interacts with PMD, PHY, and MAC. Therefore, an ATS for portions of SMT that use MAC PDUs can be speci- fied in TTCN, while other portions require other approaches. Copyright American National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosu
31、ka/9961031100 Not for Resale, 05/08/2007 22:19:00 MDTNo reproduction or networking permitted without license from IHS -,-,- iv d) A Protocol Implementation Conformance Statement (PICS) proforma for FDDI that provides a statement of the mandatory and optional requirements of each of the four FDDI bas
32、e standards. The PICS profor- ma is used to identify requirements for conformance testing and to spec- ify optional functionality requirements, particularly by workshops for functional standards and profiles. This standard was developed by Task Group X3T9.3 of Accredited Standards Committee X3 durin
33、g 1990, 1991, and 1992. The standards approval process started in 1992. Requests for interpretations, suggestions for improvement or addenda, or defect reports are welcome. They should be sent to the X3 Secretariat, Information Technology Industry Council, 1250 Eye Street, NW, Suite 200, Washington,
34、 DC 20005. This standard was processed and approved for submittal to ANSI by Accredited Standards Committee on Information Technology, X3. Committee approval of the standard does not imply that all committee members voted for the standard. At the time it approved this standard, the X3 Committee had
35、the following members: James D. Converse, Chair Donald C. Loughry, Vice-Chair Kate McMillan, Secretary Organization RepresentedName of Representative American Nuclear SocietyGeraldine C. Main Sally Hartzell (Alt.) AMP, Inc. Edward Kelly Charles Brill (Alt.) Apple Computer, IncDavid K. Michael Jerry
36、Kellenbenz (Alt.) AT there may be a MAC entity on a path and there is always a PHY receiver and a PHY transmitter. In the case of concentrators more than one PHY entity may be concatenated on one repeating path. To test an FDDI PHY path it is first necessary to initialize at least one port and estab
37、lish a path through the node. An FDDI node has one or more ports. A port consists of a PMD entity and an associated PHY entity. The input and output of a port use the same Media Interface Connector (MIC). A path is distinct from a PHY entity. A path may enter on the input of one port and its associa
38、ted PHY entity receiver function and exit on the output of that same port and PHY entity transmitter function, or it can exit on the output of another port and its associated PHY entity transmitter function. After the input enters through the connector input the signal level is interpreted by the PM
39、D Receiver entity, which continually makes a decision about whether each received code bit signal level is a one or a zero. The PMD Receiver then passes the code bit stream onto the PHY Receive entity, which recovers the clock of the received signal. It then uses the recovered clock to determine whe
40、ther a level transition has occurred in each code bit interval; in the NRZI code used by FDDI a transition is a code bit one and no transition is a code bit zero. PHY then aligns groups of five code bits into symbols, and decodes those symbols into one of 16 data values, eight control values or eigh
41、t invalid values. A special unique symbol pair, called JK, is used to establish the symbol alignment and mark the start of a frame. The data symbols are reclocked from a local oscillator, and two FIFOs, called the Elasticity Buffer and Smoother provide compensation for the difference between the loc
42、al oscillator and the recovered clock. PHY also determines input lines states for the SMT entity. Input symbols are then passed to an optional MAC entity, which either repeats input frames or strips them. MAC may also originate new frames while stripping any received frames. During normal operation,
43、 when MAC is not repeating or originating frames it sources Idle symbols. The PHY transmit function either repeats packets passed to it by the PHY receiver (through the MAC entity when a MAC is present on the path), transmits frames originated by the local MAC, or sends Idle symbols. If no MAC is pr
44、esent on a path a PHY Repeat Filter detects and corrects certain invalid input symbols. The Repeat Filter is optional if there is a MAC. The sixteen possible data values and eight possible control values are then encoded in the FDDI NRZI line code and passed to the PMD transmitter as a serial bit st
45、ream. This standard tests the PHY functions of a path as shown in figure 1. Any FDDI dual attachment node has at least 4 possible paths, some which enter and exit through the same port and others which enter at the input of one port and exit at the output of another port. Concentrators, in general,
46、have more than four possible paths. This ATS specifies a conformance test for any PHY path through a node. Figure 2 illustrates the four paths through a dual attachment station in three of its configuration states. A dual attachment station has two ports, one labeled A and the other B. In the THRU s
47、tate (figure 2(a) each path enters through one port (and its PHY receiver entity) and exits through another port (and its PHY transmitter entity). In the WRAP B state (figure 2(b) a path enters and exits through the B port, while the A port is not active. In the WRAP A state (figure 2(c) a path ente
48、rs and exits through the A port, while the B port is not active. It may be more convenient to test paths that enter and exit through the same port, because it is only necessary to initialize one link, while it is necessary to initialize two links before beginning the PHY test when the path tested en
49、ters one port and exits another. Copyright American National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 22:19:00 MDTNo reproduction or networking permitted without license from IHS -,-,- ANSI X3.248-1996 6 A PHY path 1 MAC PHY path 2