ISO/IEC 9314-9:2000

Information technology - Fibre Distributed Data Interface (FDDI) - Part 9: Low-cost fibre physical layer medium dependent (LCF-PMD)

The Fibre Distributed Data Interface (FDDI) is intended for use in a high-performance general purpose multi-station network and is designed for efficient operation with a peak data rate of 100 Mbit/s. It uses a Token Ring architecture with optical fibre as the primary transmission medium. FDDI provides for hundreds of stations operating over an extent of tens of kilometers. The FDDI Part: Token ring low-cost fibre physical layer medium dependent standard (LCF-PMD) specifies the lower sublayer of the Physical Layer for FDDI. It thus specifies the power levels and characteristics of the optical transmitter and receiver, and the interface optical signal requirements including jitter. LCF-PMD also specifies the connector receptacle footprint, the requirements of conforming FDDI optical fibre cablings, and the permissible bit error rates. LCF-PMD is one of a set of alternative international standard PMDs for FDDI. This set includes the original PMD, the Single Mode Fibre PMD (SMF-PMD), and the Twisted-Pair PMD (TP-PMD).

General Information

• Status: Published
• Publication Date: 13-Jun-2000
• ICS: 35.200 - Interface and interconnection equipment
• Technical Committee: ISO/IEC JTC 1/SC 25 - Interconnection of information technology equipment
• Current Stage: PPUB - Publication issued
• Start Date: 14-Jun-2000
• Completion Date: 31-Jul-2000

Overview

ISO/IEC 9314-9:2000 defines the Low-Cost Fibre Physical Layer Medium Dependent (LCF‑PMD) for the Fibre Distributed Data Interface (FDDI). FDDI is a token‑ring, optical‑fibre local area network technology designed for high‑performance multi‑station networks at a peak data rate of 100 Mbit/s. This part specifies the lower sublayer of the Physical Layer (PMD) for a low‑cost fibre implementation, covering optical transmitter/receiver characteristics, connector footprints, cabling requirements and interface signal limits including jitter and permissible bit error rates.

Key topics and technical requirements

• Physical layer scope: Defines the PMD lower sublayer services and interfaces between LCF‑PMD, PHY and SMT layers.
• Optical transmitter & receiver: Power levels, spectral characteristics, extinction ratio and timing behaviour required for interoperability.
• Signal integrity & jitter: Optical signal requirements including jitter allocation, distortion, and measurement/test patterns.
• Connector and receptacle: Standardized LCF‑MIC receptacle/plug footprint and mechanical/optical testing requirements (insertion/withdrawal, pull tests, repeatability).
• Cabling specification: Approved fibre types, bandwidth and attenuation values, allowable connection/splice losses and alternative cabling guidance.
• Interface signals: Definitions such as Signal_Detect and station bypass interfaces.
• Test and conformance: Informative annexes include test methods for optical power, spectrum, rise/fall times, jitter (RJ/DDJ), extinction ratio, and conformance procedures for connectors and cabling.

Applications and who uses this standard

ISO/IEC 9314-9:2000 is used wherever a cost‑effective optical PMD is required for legacy or specialized FDDI networks. Typical users include:

• Network equipment manufacturers designing FDDI optical transceivers and interface modules.
• System integrators and installers implementing campus or building fibre rings using LCF cabling and connectors.
• Test laboratories and QA teams validating transmitter/receiver specs, jitter budgets and connector reliability.
• Standards and compliance engineers ensuring interoperability across FDDI station equipment.

Practical use cases include campus backbones, inter‑building links and intra‑building distribution where FDDI topology and 100 Mbit/s token‑ring behavior are required.

Related standards

• ISO/IEC 9314-1 (PHY), -2 (MAC), -3 (PMD), -4 (SMF‑PMD), -6 (SMT) and other FDDI parts covering protocol, station management and conformance testing.

Keywords: ISO/IEC 9314-9:2000, FDDI, LCF-PMD, low-cost fibre, physical layer, PMD, 100 Mbit/s, optical transmitter, optical receiver, jitter, connector footprint, cabling, bit error rate.

Standards Content (Sample)

INTERNATIONAL
ISO/IEC
STANDARD
9314-9
First edition
2000-06
Information technology –
Fibre Distributed Data Interface (FDDI) −
Part 9:
Low-cost fibre physical layer medium dependent
(LCF-PMD)
Reference number
INTERNATIONAL
ISO/IEC
STANDARD
9314-9
First edition
2000-06
Information technology –
Fibre Distributed Data Interface (FDDI) −
Part 9:
Low-cost fibre physical layer medium dependent
(LCF-PMD)
 ISO/IEC 2000
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any
means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher.
ISO/IEC Copyright Office Case postale 56 CH-1211 Genève 20 Switzerland
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– 2 – 9314-9 © ISO/IEC:2000(E)
CONTENTS
Page
FOREWORD . 5
INTRODUCTION .6
Clause
1 Scope . 7
2 Normative references. 8
3 Definitions. 9
4 Conventions and abbreviations . 13
4.1 Conventions. 13
4.2 Abbreviations. 13
5 General description. 13
5.1 Ring Overview . 13
5.2 Environment . 14
5.2.1 General. 14
5.2.2 Campus inter-building distribution environment . 15
5.2.3 Intra-building distribution environment. 15
5.2.4 Workstation distribution environment. 15
6 Services. 18
6.1 General. 18
6.2 LCF-PMD–to–PHY services . 18
6.2.1 Introduction. 18
6.2.2 PM_UNITDATA.request . 18
6.2.3 PM_UNITDATA.indication . 20
6.2.4 PM_SIGNAL.indication. 20
6.3 LCF-PMD-to-SMT services . 21
6.3.1 Introduction. 21
6.3.2 SM_PM_CONTROL.request. 21
6.3.3 SM_PM_BYPASS.request. 22
6.3.4 SM_PM_SIGNAL.indication. 22
7 Media interface connector specification. 23
7.1 Introduction. 23
7.2 General information . 23
7.2.1 Standardized connector . 23
7.2.2 Testing recommendations . 23
7.2.3 Station labelling . 23
7.3 LCF-MIC receptacle. 23
7.4 LCF-MIC plug . 23
7.4.1 LCF-MIC ferrule . 24

9314-9  ISO/IEC:2000(E) – 3 –
8 Media signal interface . 24
8.1 General. 24
8.2 Active output interface . 25
8.3 Active input interface . 25
8.4 Station bypass interface. 25
9 Interface signals . 26
9.1 General. 26
9.2 Optical receiver. 26
9.2.1 Signal_Detect . 26
9.3 Optical transmitter . 28
10 Cabling interface specification . 28
10.1 General. 28
10.2 Cabling specification. 28
10.2.1 Fibre types. 28
10.2.2 Bandwidth and attenuation values. 28
10.3 Bypassing. 29
10.4 Connectors and splices. 29
Annex A (informative) Test methods. 30
A.1 General. 30
A.2 Active output interface . 30
A.2.1 Optical power measurements . 30
A.2.2 Optical spectrum measurements . 30
A.2.3 Rise/fall response time measurements . 30
A.2.4 Jitter measurements. 30
A.2.5 Extinction ratio . 31
A.3 Active input interface . 31
A.4 Distortion and jitter contributions. 31
A.5 Distortion and jitter measurements. 32
A.5.1 DCD measurements . 32
A.5.2 RJ and DDJ measurements. 32
A.6 DDJ test pattern for jitter measurements. 34
Annex B (informative) Alternative cabling usage. 35
B.1 Alternative fibre sizes . 35
B.2 Connection losses . 35
B.2.1 Loss budgets . 35
B.2.2 Test specifications and procedure. 36
B.3 Optical bypass switches. 36
Annex C (informative) Electrical interface considerations . 37
Annex D (informative) Example of system jitter allocation. 39
D.1 Jitter sources . 39
D.2 Jitter calculation example. 39

– 4 – 9314-9 © ISO/IEC:2000(E)
Annex E (informative) LCF-MIC requirements and testing . 41
E.1 Combined LCF-MIC mechanical-optical requirements . 41
E.2 LCF-MIC testing definitions and conditions . 41
E.3 LCF-MIC receptacle axial pull test . 42
E.3.1 Purpose . 42
E.3.2 Test method. 42
E.4 LCF-MIC receptacle insertion/withdrawal force test. 42
E.4.1 Purpose . 42
E.4.2 Test method. 42
E.5 LCF-MIC receptacle optical repeatability test . 42
E.5.1 Purpose . 42
E.5.2 Test method. 42
E.6 LCF-MIC receptacle optical cross plug repeatability test . 43
E.6.1 Purpose . 43
E.6.2 Test method. 43
E.7 LCF-MIC plug axial pull test. 43
E.7.1 Purpose . 43
E.7.2 Test method. 43
E.8 LCF-MIC plug insertion/withdrawal force test . 43
E.8.1 Purpose . 43
E.8.2 Test method. 43
E.9 LCF-MIC plug off axis pull test. 43
E.9.1 Purpose . 43
E.9.2 Test method. 43
E.10 Cable/LCF-MIC plug pull strength test . 43
E.10.1 Purpose . 43
E.10.2 Test method. 44
Annex F (informative) Alternate Optical Interface Connector . 45
Annex G (informative) Labelling considerations . 46
G.1 General. 46
G.2 FDDI station labelling. 46
Bibliography . 48

9314-9  ISO/IEC:2000(E) – 5 –
INFORMATION TECHNOLOGY –
FIBRE DISTRIBUTED DATA INTERFACE (FDDI) –
Part 9: Low-cost fibre physical layer medium dependent (LCF-PMD)
FOREWORD
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission)
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. 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, 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 least 75 % of the national bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of
patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights.
International standard ISO/IEC 9314-9 was prepared by subcommittee 25: Interconnection of
information technology equipment, of ISO/IEC joint technical committee 1: Information
technology.
International Standards are drafted in accordance with the ISO/IEC Directives, Part 3.
Annexes A, B, C, D, E, F and G are for information only.
ISO/IEC 9314 consists of the following parts, under the general title Information technology –
Fibre Distributed Data Interface (FDDI):
– Part 1: Token Ring Physical Layer Protocol (PHY)
– Part 2: Token Ring Media Access Control (MAC)
– Part 3: Physical Layer Medium Dependent (PMD)
– Part 4: Single Mode Fibre Physical Layer Medium Dependent (SMF-PMD)
– Part 5: Hybrid Ring Control (HRC)
– Part 6: Station Management (SMT)
– Part 7: Physical Layer Protocol (PHY-2)
– Part 8: Media Access Control-2 (MAC-2)
– Part 13: Conformance Test Protocol Implementation – Conformance Statement (CT-PICS)
Proforma
– Part 20: Abstract Test Suite for FDDI – Physical Medium Dependent Conformance Testing
1)
(PMD-ATS)
– Part 21: Abstract Test Suite for FDDI – Physical Layer Protocol Conformance Testing
1)
(PHY-ATS)
– Part 25: Abstract test suite for FDDI – Station Management Conformance Testing (SMT-ATS)
1)
– Part 26: Abstract Test Suite for FDDI – Media Access Control Conformance Testing (MAC-ATS)
___________
1)
To be published.
– 6 – 9314-9 © ISO/IEC:2000(E)
INTRODUCTION
The Fibre Distributed Data Interface (FDDI) is intended for use in a high-performance general
purpose multi-station network and is designed for efficient operation with a peak data rate of
100 Mbit/s. It uses a Token Ring architecture with optical fibre as the primary transmission
medium. FDDI provides for hundreds of stations operating over an extent of tens of
kilometers.
The FDDI Part: Token ring low-cost physical layer medium dependent (LCF-PMD) standard
specifies the lower sublayer of the Physical Layer for FDDI. As such it specifies the power
levels and characteristics of the optical transmitter and receiver, and the interface optical
signal requirements including jitter. LCF-PMD also specifies the connector receptacle
footprint, the requirements of conforming FDDI optical fibre cablings, and the permissible bit
error rates.
LCF-PMD is one of a set of alternative international standard PMDs for FDDI. This set
includes the original PMD, the Single Mode Fibre PMD (SMF-PMD), and the Twisted-Pair
PMD (TP-PMD).
The set of FDDI standards includes the following standards:
a) a FDDI Part: token ring physical layer protocol (PHY), which 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;
b) a FDDI Part: token ring media access control (MAC), which specifies the lower sublayer of
the data link layer for FDDI, including the access to the medium, addressing, data
checking, and data framing;
c) a FDDI Part: token ring station management (SMT), which specifies the local portion of the
system management application process for FDDI, including the control required for
proper operation of a station in an FDDI ring.

9314-9  ISO/IEC:2000(E) – 7 –
INFORMATION TECHNOLOGY –
FIBRE DISTRIBUTED DATA INTERFACE (FDDI) –
Part 9: Low-cost fibre physical layer medium dependent (LCF-PMD)
1 Scope
This part of ISO/IEC 9314 specifies the requirements for the Fibre Distributed Data Interface
(FDDI); token ring low-cost fibre physical layer medium dependent (LCF-PMD).
FDDI provides a high-bandwidth (100 Mbit/s), general-purpose interconnection among
computers and peripheral equipment using fibre optics as the primary transmission medium.
FDDI can be configured to support a sustained data transfer rate of at least 80 Mbit/s
(10 Mbyte/s). FDDI provides connectivity for many nodes distributed over distances of several
kilometers in extent. Default values for FDDI are calculated on the basis of 1 000 physical
links and a total fibre path length of 200 km (typically corresponding to 500 nodes and 100 km
of dual fibre cable).
FDDI consists of:
a) a Physical Layer (PL), which is divided into two sublayers
1) A Physical Layer, Medium Dependent (PMD) sublayer (ISO/IEC 9314-3), with several
alternative medium choices, 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 medium 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 original PMD standard (ISO/IEC 9314-3), called PMD, defines attachment to multi-
mode fibre up to 2 km, while this LCF-PMD, optically interoperable with the original
PMD, defines low-cost attachments to multi-mode fibre up to 500 m. Additional PMD
sublayer standards are for attachment to single mode fibre (SMF-PMD), and twisted-
pair up to 100 m (TP-PMD);
2) A Physical Layer Protocol (PHY) sublayer (ISO/IEC 9314-1), and its enhancement,
(PHY-2), which provides connection between the PMD and the Data 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 conditioning 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 code;
b) a Data Link Layer (DLL), which is divided into two or more sublayers
1) An optional Hybrid Ring Control (HRC) (ISO/IEC 9314-5), which provides multiplexing
of packet and circuit switched data on the shared FDDI medium. HRC comprises two
internal components, a Hybrid Multiplexer (H-MUX) and an Isochronous MAC (I-MAC).
H-MUX maintains a synchronous 125 µs 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) (ISO/IEC 9314-2), and its enhancement (MAC-2),
which provides fair and 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;

– 8 – 9314-9 © ISO/IEC:2000(E)
3) An optional Logical Link Control (LLC), which provides a common protocol for 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 not specified by FDDI;
c) a Station Management (SMT), which provides the control 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 isolation and recovery, and scheduling policies.
FDDI LCF-PMD is a supporting document to FDDI PHY and FDDI PHY-2 which should be
read in conjunction with it. The FDDI SMT document should be read for information pertaining
to supported FDDI node and network configurations. The original FDDI PMD should be read
for issues relating to FDDI LCF-PMD to FDDI PMD optical interoperability.
ISO/IEC 9314 specifies the interfaces, functions, and operations necessary to ensure
interoperability between conforming FDDI implementations. This standard provides a
functional description. Conforming implementations may employ any design technique that
does not violate interoperability.
2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this part of ISO/IEC 9314. For dated references, subsequent
amendments to, or revisions of, any of these publications do not apply. However, parties to
agreements based on this part of ISO/IEC 9314 are encouraged to investigate the possibility
of applying the most recent editions of the normative documents indicated below. For undated
references, the latest edition of the normative document referred to applies. Members of IEC
and ISO maintain registers of currently valid International Standards.
IEC 60793-1-1, Optical fibres – Part 1-1: Generic specification – General
IEC 60793-1-2, Optical fibres – Part 1: Generic specification – Section 2: Measuring methods
for dimensions
IEC 60793-1-4, Optical fibres – Part 1: Generic specification – Section 4: Measuring methods
for transmission and optical characteristics
IEC 60793-2, Optical fibres – Part 2: Product specifications
IEC 60874-14, Connectors for optical fibres and cables – Part 14: Sectional specification for
fibre optic connector – Type SC
IEC 60874-19, Connectors for optical fibres and cables – Part 19: Sectional specification for
fibre optic connector – Type SC-D(uplex)
ISO/IEC 11801:1995, Information technology – Generic cabling for customer premises
ISO/IEC 9314-1:1989, Information processing systems – Fibre Distributed Data Interface
(FDDI) – Part 1: Token Ring Physical Layer Protocol (PHY)
ISO/IEC 9314-2:1989, Information processing systems – Fibre Distributed Data Interface
(FDDI) – Part 2: Token Ring Media Access Control (MAC)
ISO/IEC 9314-3:1990, Information processing systems – Fibre Distributed Data Interface
(FDDI) – Part 3: Token Ring Physical Layer, Medium Dependent (PMD)

9314-9  ISO/IEC:2000(E) – 9 –
3 Definitions
For the purposes of this part of ISO/IEC 9314, the following definitions apply. Other parts of
ISO/IEC 9314, e.g. FDDI MAC, PHY and PMD, may contain additional definitions of interest.
3.1
attenuation
level of optical power loss, expressed in decibels
3.2
average power
the optical power measured using an average reading power meter when the FDDI station is
transmitting a stream of Halt symbols
3.3
bypass
the ability of a station to isolate itself optically from the FDDI network while maintaining the
continuity of the cabling
3.4
centre wavelength
the average of the two wavelengths measured at the half amplitude points of the power
spectrum
3.5
code bit
the smallest signalling element used by the Physical Layer for transmission on the medium
3.6
concentrator
FDDI node that has additional PHY/PMD entities beyond those required for its own
attachment to an FDDI network. These additional PHY/PMD entities are for the attachment of
other FDDI nodes (including other concentrators) in a tree topology
3.7
connector plug
device used to terminate a fibre optic cable
3.8
connector receptacle
fixed or stationary half of a connection that is mounted on a panel/bulkhead. Receptacles
mate with plugs
3.9
counter-rotating
arrangement whereby two signal paths, one in each direction, exist in a ring topology
3.10
dual attachment concentrator
concentrator that offers two attachments to the FDDI network which are capable of
accommodating a dual (counter-rotating) ring
3.11
dual attachment station
a station that offers two attachments to the FDDI network which are capable of
accommodating a dual (counter-rotating) ring

– 10 – 9314-9 © ISO/IEC:2000(E)
3.12
dual ring (FDDI dual ring)
two FDDI rings that operate as (a pair of) counter-rotating logical rings
3.13
entity
an active service or management element within an Open Systems Interconnection (OSI)
layer, or sublayer
3.14
extinction ratio
the ratio of the low, or off optical power level (PL) to the high, or on optical power level (PH)
when the station is transmitting a stream of Halt symbols
Extinction ratio (%) = (PL/PH) × 100
3.15
fibre
dielectric material that guides light; waveguide
3.16
fibre optic cable
a cable containing one or more optical fibres
3.17
interchannel isolation
the ability to prevent undesired optical energy from appearing in one signal path as a result of
coupling from another signal path; cross talk
3.18
jitter
the variation in synchronization between bits in the FDDI signalling bit stream
3.19
jitter, data dependent (DDJ)
jitter that is related to the transmitted symbol sequence
NOTE DDJ is caused by the limited bandwidth characteristics and imperfections in the optical channel
components. DDJ results from non-ideal individual pulse responses and from variation in the average value of the
encoded pulse sequence which may cause base-line wander and may change the sampling threshold level in the
receiver.
3.20
jitter, duty cycle distortion (DCD)
distortion usually caused by propagation delay differences between low-to-high and high-to-
low transitions
NOTE DCD is manifested as a pulse width distortion of the nominal baud time.
3.21
jitter, random (RJ)
RJ is caused by thermal noise
NOTE Random jitter may be modeled as a Gaussian process. The peak-to-peak value of RJ is of a probabilistic
nature and thus any specific value requires an associated probability.
3.22
LCF-MIC plug
male part of the LCF-MIC which terminates a fibre optical cable

9314-9  ISO/IEC:2000(E) – 11 –
3.23
LCF-MIC receptacle
female part of the LCF-MIC which is contained in an FDDI node
3.24
logical ring
set of MACs serially connected to form a single ring
3.25
media interface connector (MIC)
a mated connector pair that provides an attachment between an FDDI node and a fibre optic
cabling
NOTE When referring to the original PMD’s MIC, the term MIC is used. When referring to the LCF-PMD MIC, the
term LCF-MIC is used. The LCF-MIC consists of two parts; an LCF-MIC plug and an LCF-MIC receptacle.
3.26
network (FDDI network)
a collection of FDDI nodes interconnected to form a trunk, or a tree, or a trunk with multiple
trees. This topology is sometimes called a dual ring of trees
3.27
node
a generic term applying to any FDDI ring attachment (station or concentrator)
3.28
numerical aperture (NA)
the sine of the radiation or acceptance half angle of an optical fibre, multiplied by the
refractive index of the material in contact with the exit or entrance face
3.29
optical fall time
the time interval for the falling edge of an optical pulse to transition from 90 % to 10 % of the
pulse amplitude
3.30
optical reference plane
plane that defines the optical boundary between the MIC Plug and the MIC Receptacle
3.31
optical rise time
time interval for the rising edge of an optical pulse to transition from 10 % to 90 % of the pulse
amplitude
3.32
original PMD
the PMD defined in ISO/IEC 9314-3
NOTE The original PMD supports multi-mode fibre optic cable with an 11 dB loss budget.
3.33
physical connection
the full-duplex physical layer association between adjacent PHY entities (in concentrators or
stations) in an FDDI network, i.e. a pair of Physical Links
3.34
physical link
the simplex path (via PMD and attached medium) from the transmit function of one PHY entity
to the receive function of an adjacent PHY entity (in concentrators or stations) in an FDDI
network
– 12 – 9314-9 © ISO/IEC:2000(E)
3.35
primitive
an element of the services provided by one entity to another
3.36
receiver (optical)
opto-electronic circuit that typically converts an optical signal to an electrical logic signal
3.37
ring
a set of stations wherein information is passed sequentially between stations, each station in
turn examining or copying the information, finally returning it to the originating station
3.38
services
FDDI services provided by one FDDI entity to another
NOTE Data services are provided to a higher layer entity; management services are provided to a management
entity in the same or another layer.
3.39
single attachment concentrator
concentrator that offers one attachment to the FDDI network
3.40
single attachment station
a station that offers one attachment to the FDDI network
3.41
spectral width, full width half maximum (FWHM)
the absolute difference between the wavelengths at which the spectral radiant intensity is
50,0 % of the maximum power
3.42
station
an addressable node on an FDDI network capable of transmitting, repeating, and receiving
information. A station has exactly one SMT and at least one MAC, one PHY, and one PMD
3.43
transmitter (optical)
an opto-electronic circuit that typically converts an electrical logic signal to an optical signal
3.44
trunk
a physical loop topology, either open or closed, employing two optical fibre signal paths, one
in each direction (i.e. counter-rotating), forming a sequence of peer connections between
FDDI nodes
NOTE When the trunk forms a closed loop it is sometimes called a trunk ring.
3.45
tree
a physical topology consisting of a hierarchy of master-slave connections between a
concentrator and other FDDI nodes (including subordinate concentrators)

9314-9  ISO/IEC:2000(E) – 13 –
4 Conventions and abbreviations
4.1 Conventions
The terms SMT, MAC, PHY, and PMD, when used without modifiers, refer specifically to the
local instances of these entities.
Low lines (e.g. control_action) are used as a convenience to mark the name of signals,
functions, and the like, which might otherwise be misinterpreted as independent individual
words if they were to appear in text.
The use of a period (e.g. PM_UNITDATA.request) is equivalent to the use of low lines except
that a period is used as an aid to distinguish modifier words appended to an antecedent
expression.
The use of a colon (e.g. N:PM_UNITDATA.request) distinguishes between two or more
instances of the same signal where N designates the other source/destination entity.
4.2 Abbreviations
AII Active Input Interface
AOI Active Output Interface
ANS_Max Maximum acquisition time (no signal)
AS_Max Maximum acquisition time (signal)
BER Bit Error Rate
BERT Bit Error Rate Tester
d.c. direct current
DCD Duty Cycle Distortion (jitter)
DDJ Data Dependent Jitter
ECL Emitter Coupled Logic
FOTP Fibre Optic Test Procedure
FWHM Full Width Half Maximum
LED Light Emitting Diode
LCF-MIC LCF-PMD MIC Connector
LS_Max Maximum line state change time
MIC Media Interface Connector
NA Numerical Aperture
NRZI Non Return to Zero, Invert on ones
RJ Random Jitter
SAE Static Alignment Error (clock offset error)
5 General description
5.1 Ring Overview
A ring consists of a set of stations logically connected as a serial string of stations and
transmission media to form a closed loop. Information is transmitted sequentially, as a stream
of suitably encoded symbols, from one station to the next. Each station generally regenerates
and repeats each symbol and serves as the means for attaching one or more devices to the
ring for the purpose of communicating with other devices on the ring. The method of actual
physical attachment to the FDDI ring may vary and is dependent on specific application
requirements as described in subsequent paragraphs.

– 14 – 9314-9 © ISO/IEC:2000(E)
The basic building block of an FDDI ring is a physical connection as shown in Figure 1. A
physical connection consists of the Physical Layers (each composed of a PMD and a PHY
entity) of two stations that are connected over the transmission medium by a Primary Link and
a Secondary Link. A Primary Link consists of an output, called Primary Out, of a Physical
Layer, communicating over a Primary medium to the input, called Primary In, of a second
Physical Layer. The Secondary Link consists of the output, called Secondary Out, of the
second Physical Layer communicating over a Secondary medium to the input, called
Secondary In, of the first Physical Layer. Physical connections may be subsequently logically
connected within stations, via attached MACs or other means, to create the network. As such,
the function of each station is implementer-defined and is determined by the specific
application or site requirements.
Two classes of stations are defined: dual (attachment) and single (attachment). FDDI trunk
rings may be composed only of dual attachment stations which have two PMD entities (and
associated PHY entities) to accommodate the dual ring. Concentrators provide additional
PMD entities beyond those required for their own attachment to the FDDI network, for the
attachment of single attachment stations which have only one PMD and thus should not
directly attach to the FDDI trunk ring.
The example of Figure 2 shows the concept of multiple physical connections used to create
logical rings. As shown, the logical sequence of MAC connections is stations 1, 3, 5, 8, 9, 10,
and 11. Stations 2, 3, 4, and 6 form an FDDI trunk ring. Stations 1, 5, 7, 10, and 11 are
attached to this ring by lobes branching out from the stations that form it. Stations 8 and 9 are
in turn attached by lobes branching out from station 7. Stations 2, 4, 6, and 7 are
concentrators, serving as the means for attaching multiple stations to the FDDI ring.
Concentrators may or may not have MAC entities and station functionality. The concentrator
examples of Figure 2 do not show any MACs although their presence is implied by the
designation of these concentrators as stations.
Connection to the physical medium as established by PMD is controlled by the station
insertion and removal algorithms of Station Management (SMT) which are beyond the scope
of this standard.
Physical Connection
Physical Link
Cable
Plant
PH_UNITDATA.request
PH_UNITDATA.indication
OUT IN
Medium
PHY PMD PMD PHY
IN OUT
PH_UNITDATA.indication
PH_UNITDATA.request
STATION N
STATION M
Physical Link
Figure 1 — FDDI links and connections
5.2 Environment
5.2.1 General
As shown in Figure 2 and as described in 5.1, an FDDI network consists of a virtually
unlimited number of connected stations. SMT establishes the physical connections between
stations, and the correct internal station configurations, to create an FDDI network. It is
understood that restrictions of the transmission media as defined (i.e. dynamic range and
bandwidth) may place limits on realizable physical configurations. Tradeoffs may be made
within specific site applications, such as distance versus optical bypassing, consistent with
these limitations.
9314-9  ISO/IEC:2000(E) – 15 –
While not intended to be limiting, FDDI has been defined to provide for a multi-level private
network serving a campus or multi-building environment described in ISO/IEC 11801.
According to figure 1 of ISO/IEC 11801 a generic cabling system consists of the following
subsystems: the campus backbone cabling subsystem, the building backbone cabling
subsystem, and the horizontal cabling subsystem. These subsystems describe an inter-
building distribution environment, an intra-building distribution environment, and a work
station distribution environment. The following subclauses discuss the requirements to be
considered when implementing FDDI networks.
5.2.2 Campus inter-building distribution environment
The campus environment is characterized by stations distributed across multiple buildings,
utilizing underground fibre cable distribution plant, where the distances might be as short as
several hundred metres and as long as tens of kilometres. At the shortest distances, the FDDI
LCF-PMD (Low-Cost Fibre) interface defined by this standard might possibly be used, but it
would generally be expected that the original PMD interface ISO/IEC 9314-3 would be used
for inter-building distances up to 2 km.
At the longer distances, a campus environment might use private fibre, and thus rely on the
FDDI SMF-PMD (Single-Mode Fibre) defined in ISO/IEC 9314-4, while connections that
required public links could rely on an FDDI SONET physical mapping interface.
This environment would typically be expected to be implemented as a dual-trunk ring, though
centralized concentrators with radial distribution to remote sites (buildings) can be used (see
ISO/IEC 11801). Optical bypass is also a candidate for this environment as transmission link
reliability considerations are paramount when underground fibre cabling is utilized due to the
great difficulty in restoring services if the link is physically damaged or lost.
5.2.3 Intra-building distribution environment
The intra-building environment is characterized by stations located throughout a building,
utilizing standard intra-building cable distribution models, where the distances typically range
from a few meters to a thousand metres. For more details on generic cabling within customer
premises, refer to ISO/IEC 11801.
At the very shortest distances, the FDDI TP-PMD (Twisted-Pair) interface might be used but it
would generally be expected that the FDDI LCF-PMD (Low-Cost Fibre) interface would be
used for distances up to 500 m and the original FDDI PMD interface for intra-building
distances above LCF-PMD limits.
This environment would typically consist of interconnections between concentrators located in
telecommunications closets and facilities such as floor distributors. However, it would also be
expected that some data centre to data centre interconnections would be implemented in this
environment as well using dual attachment stations. Concentrators would be interconnected
by either single or dual attachment. Optical bypass is also a candidate for this environment,
but less likely given the protection provided by both dual rings and concentrators.
5.2.4 Workstation distribution environment
The workstation environment is characterized by stations located within a short distance of a
floor distributor. It would typically utilize standard intra-building cable distribution models,
where distances are typically less than 100 m, and distances between distribution closets are
typically less than 500 m. For distribution from the workstation to the closest distribution
closet, the FDDI TP-PMD and LCF-PMD interfaces would typically be used. For distribution
where the workstation is more than one distribution closet away from the concentrator, the
FDDI LCF-PMD interface would typically be used, with the original FDDI PMD only being used
for distances above 500 m.
The environment would typically consist of single attachment interconnections from
workstations in the office or laboratory, to concentrators located in floor distributors.

– 16 – 9314-9 © ISO/IEC:2000(E)
Occasionally, dual attachment stations might be served, but it is expected that the link
distances as described above would still apply. Optical bypass is also a candidate for this
environment, but less likely given the protection provided by both dual rings and
concentrators.
STATION 5
SINGLE
MAC
H
STATION 3
STATION 4
DUAL
CONCENTRATOR
MAC G
DE FI
STATION 6
CONCENTRATOR
J
S
K
STATION 2
STATION 9 STATION 7
CONCENTRATOR
SINGLE CONCENTRATOR
CT
MAC L
BW U P OM
A X V N
MAC MAC MAC MAC
STATION 1 STATION 11 STATION 10 STATION 8
SINGLE SINGLE SINGLE SINGLE
Figure 2 — FDDI topology example

9314-9  ISO/IEC:2000(E) – 17 –
foc
foc
foc foc
fob fob
fob
fo&tp fo&tp
fo&tp fo&tp
fo&tp
fo&tp
fo&tp
Building
FDDI concentrator
FDDI user station
foc
fibre cabling (PMD, SMF and SPM links)
fob
fibre cabling (PMD and LCF-PMD links)
fo&tp
fibre and twisted-pair cabling (PMD, LCF-PMD and TP-PMD links)
Figure 3 — FDDI representative distribution environment example

– 18 – 9314-9 © ISO/IEC:2000(E)
6 Services
6.1 General
This clause specifies the services provided by the LCF-PMD. These services do not imply any
particular implementation or any interface.
NOTE These services for LCF-PMD are identical to those defined in the PMD; they are included here for
completeness, and changes are purely editorial.
Services described are:
(a) LCF-PMD services provided to the local Physical Protocol (PHY) entity
(indicated by PM_ prefix);
(b) LCF-PMD services provided to the local Station Management (SMT) entity
(indicated by SM_PM_ prefix).
An optional qualifier is sometimes needed to identify a signal unambiguously where there are
multiple instances of the same signal within a service interface (indicated by the “(N:)” prefix).
Thus, a prefix of (N:)PM_ or (N:)SM_PM_ indicates that an LCF-PMD could duplicate a signal
a number of times and identify each signal with a unique qualifier. For example, an LCF-PMD
in a dual station would use A:PM_ and B:PM_ as prefixes when required, whereas an LCF-
PMD in a single station may only use PM_ as a prefix. Concentrators may use other qualifiers,
such as M1:PM_ through Mn:PM_, to uniquely identify a signal.
Figure 4 shows the block diagram organization of the FDDI Low-Cost Fibre Physical Medium
Dependent (LCF-PMD) including the separate functions, intended to show physical
implementation or physical orientation of the components within an FDDI station. As
described, the interfaces and signals between PMD, PHY
...