ISO/IEC 9314-7:1998

Information technology - Fibre distributed data interface (FDDI) - Part 7: Physical layer protocol (PHY-2)

The Fibre Distributed Data Interface (FDDI), ISO/IEC 9314, is intended for use in a high-performance general purpose multi-node 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 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 Physical 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. This part of ISO/IEC 9314 for PHY-2 is an enhancement to the original FDDI standard on PHY (ISO 9314-1).

General Information

• Status: Published
• Publication Date: 30-Aug-1998
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• 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: 31-Mar-1998
• Completion Date: 02-Sep-1998

Standards Content (Sample)

INTERNATIONAL
ISO/IEC
STANDARD
9314-7
First edition
1998-08
Information technology –
Fibre distributed data interface (FDDI) –
Part 7:
Physical Layer Protocol (PHY-2)
Reference number
INTERNATIONAL
ISO/IEC
STANDARD
9314-7
First edition
1998-08
Information technology –
Fibre distributed data interface (FDDI) –
Part 7:
Physical Layer Protocol (PHY-2)
 ISO/IEC 1998
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– ii – 9314-7 © ISO/IEC :1998(E)
CONTENTS
Page
FOREWORD . iv
INTRODUCTION . v
Clause
1 Scope. 1
2 Normative references . 4
3 Definitions. 4
4 Conventions and abbreviations . 6
4.1 Conventions . 6
4.2 Abbreviations . 6
5 General description. 8
6 Services. 9
6.1 PHY-to-DLL services . 9
6.1.1 PH_UNITDATA.request . 10
6.1.2 PH_UNITDATA.indication. 10
6.1.3 PH_INVALID.indication . 12
6.2 PHY-to-PMD services . 11
6.2.1 PM_UNITDATA.request. 11
6.2.2 PM_UNITDATA.indication. 12
6.2.3 PM_SIGNAL.indication . 12
6.3 PHY-to-SMT services . 13
6.3.1 SM_PH_LINE_STATE.request . 13
6.3.2 SM_PH_STATUS.indication . 14
6.3.3 SM_PH_CONTROL.request . 15
7 Facilities. 16
7.1 Coding. 16
7.1.1 Code bit. 16
7.1.2 Code group . 16
7.2 Symbol set . 18
7.2.1 Line state symbols . 18
7.2.2 Control symbols . 18
7.2.3 Data Quartets (0-F). 20
7.2.4 Violation symbol (V) . 20
7.3 Line states. 20
7.3.1 Line State (QLS) . 20
7.3.2 Halt Line State (HLS) . 21
7.3.3 Master Line State (MLS) . 21
7.3.4 Idle Line State (ILS) . 21
7.3.5 Active Line State (ALS) . 21
7.3.6 Cycle Line State (CLS). 22
7.3.7 Noise Line State (NLS) . 22
8 Operation. 24
8.1 General . 24
8.1.1 Coding. 24
8.1.2 Clocking . 25
8.1.3 Latency. 25

9314-7 © ISO/IEC:1998(E) – iii –
8.2 Encode function . 26
8.3 Transmit function . 26
8.4 Receive function . 26
8.5 Decode function. 27
8.6 Elasticity Buffer function. 27
8.7 Line State Detection function . 29
8.8 Smoothing function . 30
8.8.1 Limit Smoother. 31
8.8.2 Target Smoother . 35
8.9 Repeat Filter function. 38
8.9.1 State RF0: IDLE. 39
8.9.2 State RF1: REPEAT. 39
8.9.3 State RF2: FILTER. 39

Annex A (informative) Ring Latency Caculation . 44
Figures
Figure 1 – Structure of FDDI standards. 3
Figure 2 – Peer Physical Connection example . 9
Figure 3 – PHY functional block diagram example. 23
Figure 4 – Limit Smoother state diagram. 33
Figure 5 – Target Smoother state diagram. 36
Figure 6 – Repeat Filter state diagram . 41
Figure 7 – FDDI-II jitter characteristics . 43
Tables
Table 1 – Symbol coding. 17

– iv – 9314-7 © ISO/IEC:1998(E)
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.
International Standard ISO/IEC 9314-7 was prepared by Joint 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 Layer Protocol (PHY) (1989)
– Part 2: Token Ring Media Access Control (MAC) (1989)
– Part 3: Physical Layer Medium Dependent (PMD) (1990)

1)
– Part 4: Single Mode Fibre Physical Layer Medium Dependent (SMF-PMD)
– Part 5: Hybrid Ring Control (HRC) (1995)
– Part 6: Station Management (SMT)
– Part 7: Physical 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 Conformance 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)
– Part 26: Media Access Control Conformance Testing (MAC-ATS) (under consideration)
___________
1)
To be published.
9314-7 © ISO/IEC:1998(E) – v –
INTRODUCTION
The Fibre Distributed Data Interface (FDDI), ISO/IEC 9314, is intended for use in a high-performance
general purpose multi-node 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 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 Physical 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 basic FDDI standards, ISO/IEC 9314, 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/IEC 9314,
b) A Physical Layer Media Dependent (PMD), which specifies the lower sublayer of the Physical
Layer of ISO/IEC 9314,
c) A Station Management (SMT), which specifies the local portion of the system management
application process of ISO/IEC 9314.
A number of extensions to ISO/IEC 9314 are completed or in process. One extension, ISO/IEC 9314-5,
for Hybrid Ring Control (HRC) commonly known as FDDI-II, extends the capability of FDDI to handle
isochronous data streams at a multiplicity of data rates. Another extension, ISO/IEC 9314-4, provides
for a single-mode optical fibre version of PMD (SMF-PMD) and will permit optical links of up 60 km.
Other extensions, addressing alternate PMDs, provide low-cost attachments 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 to ISO 9314-1 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.

9314-7 © ISO/IEC:1998(E) – 1 –
INFORMATION TECHNOLOGY —
FIBRE DISTRIBUTED DATA INTERFACE (FDDI) —
Part 7: Physical Layer Protocol (PHY-2)
1 Scope
This part of ISO/IEC 9314 specifies the Physical Layer Protocol (PHY), the upper sublayer 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 pe
...