A 1 1 10b 2b0030

noceedings of the First

i LAN-Transport Workshop

Report of the First Workshop for Local Area Network

Implementors of the NBS Specifications of the

International Standards Organization Transport

Class 4 Protocol, the IEEE 802.2 Type 1 Class 1 Link Protocol, and the IEEE 802.3 10 Megabit CSMA/CD

Specification

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Institute for Computer Sciences and Technology

Systems and Network Architecture Division

Washington, DC 20234

February 1 - 2, 1 983

-QC

100

. U56

83-2673

1983

U.S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

may'"'? 1983

r* n — O )-f acc

NBSIR 83-2673 u

PROCEEDINGS OF THE FIRST

LAN-TRANSPORT WORKSHOP

Report of the First Workshop for Local Area Network

Implementors of the NBS Specifications of the

International Standards Organization Transport

Class 4 Protocol, the IEEE 802.2 Type 1 Class 1 Link Protocol, and the IEEE 802.3 10 Megabit CSMA/CD

Specification

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Institute for Computer Sciences and Technology

Systems and Network Architecture Division

Washington, DC 20234

February 1 - 2, 1 983

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS. Ernest Ambler. Director

TABLE OF CONTENTS

Abstract 1

Workshop Summary 1

Workshop Background 1

Workshop Attendees 3

Minutes, February 1 6

Minutes, February 2 12

Future Plans 16

ABSTRACT

The National Bureau of Standards Institute for Computer Sciences and

Technology (ICST) has prepared specifications for the International

Organization for Standardization's (ISO) Class 4 Transport Protocol. At

the request of a number of companies, ICST organized a workshop for

local area network implementors of these specifications. The workshop

focused on implementation techniques and strategies so that a multivendor demonstration of these protocols can occur at a major computer

conference in the 1984 time frame. This report documents the

workshop and records implementation choices and agreements made by

the participants.

Keywords: communication protocols; computer networks; local area networks;

standards; transport protocol

WORKSHOP SUMMARY

This report documents the first workshop for local area network implementors of

the ICST specifications for the International Standards Organization (ISO)

Transport Class 4 Protocol on IEEE 802 compatible local area networks. The

workshop, held by ICST at the request of a number of companies, assembled 51 attendees from 29 organizations. It provided a forum for local network

manufacturers to share ideas and learn about Class 4 implementations, to discuss

and agree on a common set of options, and to foster a multi-vendor local network

demonstration of Class 4 Transport on an 802 LAN at a major computer conference

in 1984.

The workshop resulted in several agreements. The vendors concurred to use the

IEEE P-802.3 10 megabit baseband CSMA/CD local area network for layer 1, IEEE

P-802.2 type 1 class 1 logical link control service for layer 2, an octet of zeros

representing a "null" network independent convergence protocol for layer 3 and the

mandatory portions of the ICST specification of ISO Class 4 Transport for layer 4.

These agreements allow for the reliable transmission of data among host computers

and terminals used in the multi-vendor demonstration.

Applications such as messaging, file transfer, remote terminal access and others

will use these protocols. Details concerning these applications will be discussed at

the next workshop.

WORKSHOP BACKGROUND

Computer network protocol standards that provide for the interconnection of a wide variety of computers, terminals, and special purpose systems are needed by

computer manufacturers, vendors and users. To meet these needs, the

International Organization for Standardization (ISO) has produced an open systems

interconnection reference model for use as an aid in developing protocol standards.

The reference model defines a 7 layer architecture in which protocol standards are developed.

1
In June of 1982, the ISO produced a draft proposal for Transport layer 4. The

proposal is entitled "Information Processing Systems — Open Systems

Interconnection — Transport Protocol Specification/ISO/TC97/SC16 n-1169." It contains English proses describing the protocol mechanisms for Transport Class 0

through Class 4 services.

The ICST has developed a formal description technique for defining protocol

specifications and ICST applied the technique to the ISO Class 4 Transport. ICST

uses the resulting specification as input to a compiler that produces about fifty

percent of the protocol implementation automatically. The implementation is exercised and tested in an ICST laboratory for internal consistency and compliance

with other protocol implementation.

The remainder of this report documents the workshop and records the agreements

made during the two-day interchange of ideas.

2
LAN/Transport Workshop

ATTENDEES

Allen-Bradley Company

David C. Sweeton

Systems Division

747 Alpha Drive

Highland Heights, OH 44143

American Bell

A. A. Akiwpelu

307 Middletown/Lincroft Road

Lincroft, NJ 07738

Michael Herrick

307 Middletown/Lincroft Road

Lincroft, NJ 07738

Associated Computer Consultants

Joseph Maixner

Local Area Network Center

2901 Park Avenue

Sequel, CA 95073

BDM Corporation

John Long

International Support

7915 Jones Branch Drive

McLean, VA 22102

Roger S. Novack

7915 Jones Branch Drive

McLean, VA 22102

Boeing Computer Services Company

Sheldon Blauman

P.O. Box 24346

Seattle, WA 98124

Chris Dunlap

7980-90 Gallows Court

Vienna, VA 22180

Bolt, Berenak & Newman

John Burruss

50 Moulton Street

Cambridge, MA 02238

Ross Call on

50 Moulton Street

Cambridge, MA 02238

Burroughs Corporation

Scott A. Stein

CNG/Tredyffrin Plan

P.O. Box 203

Paoli, PA 19301

Contel Information Systems

Samuel E. Clopper, Jr. Government Systems Division

11781 Lee Jackson Highway

Fairfax, VA 22033

Control Data Corporation

J. L. Nading

4201 Lexington Avenue

Arden Hills, MN 55112

B. S. Sekhon

4201 N. Lexington Avenue

Arden Hills, MN 55112

3Com Corporation

Pamela Lawson

1390 Shorebird Way

Mountain View, CA 94043

Greg Shaw

1390 Shorebird Way

Mountain View, CA 94043

Digital Equipment Corporation

Anthony G. Lauck

1925 Andover Street

Tewksbury, MA 01876

Jeff Schriesheim

1925 Andover Street

Tewksbury, MA 01876
E-Systems ICL

Marvin Jenkel

7700 Arlington Blvd.

Falls Church, VA 22046

William Livingston

7700 Arlington Blvd.

Falls Church, VA 22046

Fisher Body

Charles D. Groff

30001 Van Dyke Avenue

Warren, MI 48090

Ford Motor Company

Shaun Devlin

Room S-2097, Scientific Research Lab

P.O. Box 2053

Dearborn, MI 48121

Melvin Gable

Room E-1174, Scientific Research Lab

P.O. Box 2053

Dearborn, MI 48121

General Motors Corporation

Ronald Floyd

GMME&D - MD/66

GM Technical Center

Warren, MI 48090-9040

Honeywell Information Systems, Inc.

William Stallings

7900 Westpark Drive

McLean, VA 22102

IBM Corporation

G. A. Deaton, Jr. IBM Communications Products Division

E87/651

P.O. Box 12195

Research Triangle Park, NC 27709

J. J. Quigley

IBM Systems Products Division

24E/037

P.O. Box 10500

Palo Alto, CA 94304

John Salter

London, England

Inco, Inc.

Paul Styger

C3I Systems Division

8260 Greensboro Drive

McLean, VA 22102

Thomas Trump

C3I Systems Division

8260 Greensboro Drive

McLean, VA 22102

Integrated Microcomputer Systems, Inc.

Kenneth Lindsay

1235 Jefferson Davis Highway

Suite 1408

Arlington, VA 22202

Howell Mei

1235 Jefferson Davis Highway

Suite 1408

Arlington, VA 22202

Intel Corporation

Allen Rochkind

SC6-056

3200 Lakeside Drive

Santa Clara, CA 95051

INTERLAN, Inc.

David Potter

3 Lyberty Way

Westford, MA 01886

Jonathan Taylor

3 Lyberty Way

Westford, MA 01886

Los Alamos National Laboratory

Don Tolmie

Los Alamos, NM 87545

4
NBI, Inc. James Moulton

Institute for Computer

Douglas McCallum

P.O. Box 9001

Boulder, CO 80301

Sciences & Technology

Room B212, Building 225

Washington, D. C. 20234

National Bureau of Standards Robert Rosenthal

Institute for Computer

Robert Blanc

Institute for Computer

Sciences & Technology

Room A231, Building 225

Washington, D. C. 20234

Sciences <5c Technology

Room B226, Building 225

Washington, D. C. 20234

Shirley Watkins

Institute for Computer

Dennis Branstad

Institute for Computer

Sciences & Technology

Room A219, Building 225

Washington, D. C. 20234

Sciences & Technology

Room B226, Building 225

Washington, D. C. 20234

North Carolina State University

Robert Carpenter

Institute for Computer

Sciences & Technology

Room A219, Building 225

Washington, D. C. 20234

Bill Chimiak

School of Physical and Mathematic

Sciences <5c School of Engineering

Box 5490

Raliegh, NC 27650

John Heafner

Institute for Computer

Sciences & Technology

Room B218, Building 225

Washington, D. C. 20234

Phillips Information Systems

Rene Archambault

5250 Ferrier

Montreal, Canada H4B1L4

Jerry Linn

Institute for Computer

Sciences & Technology

Room B212, Building 225

Washington, D. C. 20234

Systems Architects, Inc.

Ashok Kuthyar

510 W. Annandale Road

Falls Church, VA 22046

William Majurski

Institute for Computer

Sciences & Technology

Room A219, Building 225

Washington, D. C. 20234

Tektronix, Inc.

Maris Graube

P.O. Box 500

Beaverton, OR 97077

Kevin Mills

Institute for Computer

Sciences & Technology

Room B212, Building 225

Washington, D. C. 20234

Andy Luque

P.O. Box 500

Beaverton, OR 97077

Unger mann-Bass, Inc.

John M. Davidson

2560 Mission College Blvd.

Santa Clara, CA 95050 5
MINUTES

8:30 a.m.

8:45 a.m.

February 1, 1983

Introduction and Opening Remarks

Mr. Robert Blanc, ICST, welcomed the attendees to the meeting

and introduced the workshop chairman — Mr. Mauris Graube.

Mr. Graube, Chairman of the IEEE 802 local area networks (LAN)

standards committee, acknowledged a need for standard higher

layer protocols. The ISO standards for higher layer protocols

seem to be the most likely candidates to fill the need. However,

Mr. Graube believes the current ISO transport protocol specification

is too ambiguous — more specifics need to be addressed.

After providing this background, Mr. Graube cited the following

objectives for the workshop:

1) Agree upon a common set of options for Class 4 Transport,

2) Share ideas for Class 4 Transport implementation schemes,

and

3) Establish a deadline for demonstrating a multi-vendor

Class 4 capability over a local area network.

Introduction to ICST Transport Protocol Specification

Dr. John Heafner, ICST, provided an introduction to the ICST

Transport Protocol Specification. The specification consists

of six volumes:

1) Volume 1: Overview and Services,

2) Volume 2: Class 2 Transport Protocol Specification,

3) Volume 3: Class 4 Transport Protocol Specification,

4) Volume 4: Transport Service Specification,

5) Volume 5: Guidance to the Implementor, and

6) Volume 6: Guidance for Implementation Selection.

Volumes 1, 3, 4, and 5 were distributed. Volumes 2 and 6 are

not pertinent to the workshop purpose at this time.

Dr. Heafner stated that the specification is undergoing editing

and ICST expects to submit it for legal review in three to four

weeks, prior to the Federal Register announcement. Dr. Heafner

6
9:00 a.m.

11:30 a.m.

affirmed the ICST intention to maintain interoperability with

ISO transport and described the ICST Class 4 Transport as a superset of the ISO Class 4 Transport.

Overview of ICST Class 4 Transport

Mr. James Moulton, ICST, presented an overview of the details

of the ICST Class 4 Transport protocol. The following topics

were covered:

1) Overview of ISO Transport Class Structure,

2) Comparison of ISO and ICST Transports,

3) Overview of ICST Transport Services,

4) Transport Protocol Data Unit (TPDU) Structure,

5) TPDU Types, and

6) Protocol Mechanisms.

After Mr. Moulton's presentation, Dr. John Davidson, UngermannBass, listed seven concerns with the proposed Transport protocol.

These concerns were:

1) The minimum/maximum size for Transport protocol data

units is too large,

2) The sequence space is 7 or 31 bits instead of a more usual

8 or 32 bits,

3) There appears to be no way to piggyback ACKs with Data,

4) The mechanism for reducing window size seems to be an unnecessary complication of the protocol,

5) The difference between expedited flow control and expedited

acknowledgement is unclear,

6) There is no data length indication in the TPDU, and

7) There appears to be no way to address an end user.

In subsequent discussions, these seven concerns were addressed

and Dr. Davidson was satisfied that the various viewpoints behind

each concern were fully expressed.

Design Choices

Mr. John Burruss, BBN, identified several design issues that

he believed were relevant to the workshop objectives. Mr. Burruss

made suggested choices for each issue and the workshop attendees

discussed the ramifications of those choices and, where appropriate,

7
3:30 p.m.

4:00 p.m.

suggested alternative solutions. The topics explored included:

1) How to implement transport in a host environment,

2) Acknowledgement strategy,

3) Retransmission intervals,

4) Timer values,

5) Flow control strategy, and

6) Addressing.

Mr. Jerry Linn, ICST, described the service that ICST provides

to organizations interested in implementing Class 4 Transport.

The services include:

1) Protocol specification documentation,

2) A reference implementation,

3) A specification compiler,

4) Test tools including:

a) a scenario interpreter,

b) an exception generator, and

c) test scenarios and log files from tests, and

5) Cooperative testing.

Mr. Graube resumed the floor and asked how many vendors were

interested in participating in a multi-vendor demonstration

at a major computer conference in 1984. Twelve vendors were

in favor of exploring the idea further. Mr. Graube suggested

a list of topics to explore during the second day of the workshop.

These topics included:

1) Class 2 or Class 4 Transport?

2) Addressing,

3) Criteria for acceptable connect request TPDUs,

4) Maximum TPDU size,

5) Sequence number format,

6) Expedited data,

7) Non-use of checksums,

8) Defaults for optional fields,

8
4:20 p.m.

4:35 p.m.

9) Quality for optional fields,

10) Concatenated TPDUs,

11) User data in connect/disconnect request TPDUs,

12) ERR TPDU,

13) Datagram Transport (Unit Data service option), and

14) Byte-ordering conventions.

Network Layer

Mr. Ross Callon, BBN, reported upon the current Internet Protocol

(IP) work in the standards arena. Mr. Callon proposed the use

of a null network independent convergence protocol at layer

three with a single octet as the network header (value of zero)

for the multi-vendor demonstration. This is consistent with

the 'null' header format in the current ANSI X3S3.3 IP proposals.

Physical and Link Layers

Mr. Robert Rosenthal, ICST, reported upon the current LAN

standards work in the IEEE 802 Committee and in the ECMA

TG 24 committee. Both groups maintain very close liaison and

both groups have reached consensus on a number of issues including

the three separate access methods at the physical layer. The

access methods include CSMA/CD, Token Bus and Token Ring.

Each access method utilizes its own physical medium specifications.

Only the CSMA/CD and Token Bus methods are in "letter ballot";

the Token Ring method is still in IEEE 802 committee.

Mr. Rosenthal presented the current state of the IEEE 802 logical

link control documentation, also in "letter ballot," and he illustrated

the following link frame structure indicating where the proposed

null network layer header would go:

9
Silence

PREAMBLE

1 Octet Starting Frame Delimiter

6 Octets DESTINATION ADDRESS

6 Octets SOURCE ADDRESS

2 Octets Octet Count

1 Octet D L S A P

1 Octet S L S A P

1 Octet Control

1 Octet Network "Null" Header

0 to 1496

Octets

J

S

TPDU

PAD

4 Octets CRC

Silence

Mr. Rosenthal discussed the types of service provided pointing

out that both a connectionless datagram and a connection-oriented

link service are available in IEEE 802.

Mr. Graube polled the attendees and discovered that the overwhelming

majority were interested in basing the multi-vendor demonstration

on a "null" network layer header as proposed; on only the connectionless

type 1 class 1 IEEE 802 link service using 48 bit addressing; and,

10
5:00 p.m.

on the IEEE 802 CSMA/CD access method using the 10 megabit/sec

baseband coaxial cable specification.

Mr. Graube adjourned the meeting for the first day of the workshop.

11
MINUTES

February 2, 1983

During the second day of the workshop, options for use in the 1984 demonstration

were choosen, addressing was discussed, specific applications for the demonstration

were selected, and future plans including the next meeting schedule and agenda

were set.

The list of topics presented at 4:00 p.m. on February 1 was revisited. Consensus

was reached on the issues tabulated below.

Issue Choices Consensus

Class Selection Class 2, Class 4, both Class 4 was choosen

as appropriate since

all participants expect

to use the connectionless

datagram type 1 class 1 link service.

Connection

Acceptance Criteria

Data in CR

Data in DR

Quality of Service

Security Parameters

Do not use data

Do not use data

Not used

Not used

Maximum TPDU Size The Maximum TPDU size is a power of 2. As shown

on February 1, the IEEE

802 frame can be 1518; but,

the link and network

layer headers require

22 octets leaving 1496

octets for transport.

Use the negotiation

scheme specified

in Class 4 Transport.

If 2048 octets is selected ,it is understood that

the maximum TPDU

is 1496 octets.

Sequence Number 7 bits or 31 bits Participants will

implement both

lengths. A proposal

to use 7 or 31 bits

will be made and

negotiated during

connection establishment.

Fourteen companies

wanted 31 bits while

only four wanted

7 bits.

12
Issue Choices Consensus

Expedited Data The use of expedited data

is application dependent.

Participants agreed

to use the default.

Use of Checksums The use of checksums is negotiated in the ISO

specification.

Particpated agreed

to use the checksum

on the CR TPDU

but all CR's will

request that checksums

not be used. Checksums

will also be ignored

in DT TPDUs.

Version Number Use the value 1. The sender of a CR will include

the version number

parameter, the receiver

of a CR may choose

to ignore it. The

version number parameter

value will be equal

to 1.

Unimplemented or Unrecognized options

Ignore the option or return an ERR TPDU.The version number

may be ignored.

Checksums default

to the "no use option."

The maximum TPDU

default size is 128

octets. All unimplemented

or unrecognized

codes in CR and

CC TPDUs will be

ignored. All unimplemented

or unrecognized

codes in other TPDUs

requires an ERR

TPDU response.

Concatenated TPDUs Blocking of multiple

TPDUs is allowed in the

ISO specifications.

All participants

agree to receive

blocked TPDUs.

It is optional to

send blocked TPDUs.

13
Issue Choices Consensus

Error TPDUs

Unit Data

Flow Control

Conformation

Graceful Close

Sending and receiving

ERR TPDUs were discussed.

The use of the Unit Data

or Transport datagram

facility was discussed.

The use of flow control

conformation was discussed.

The use of Graceful

Close was discussed.

All implementations

must be able to

receive ERR TPDUs

but they

need not generate

them. The ERR

TPDU is useful for

debugging and as an aid in intervendor

compatibility and

security.

The Unit Data option

is not recommended

for this demonstration.

The transmission

of the flow control

conformation AK

TPDUs by the DT

transmitter is optional.

However, a DT receiver

must be able to

recognize the receipt

of flow control conformation

AK TPDUs and act

in accordance with

the specification.

This allows the data

receiver to optionally use credit reduction.

The sender of a GR should not assume

that the receiver

is anything but ISO

compatible. The

receiver of a GR

not implementing

Graceful Close can

close or return an

error.

14
Tony Lauck of Digital Equipment Corporation presented an addressing scheme

consistent with the mechanisms proposed by the IEEE 802 logical link control

committee and with the mechanisms required by Class 4 Transport. The following

diagram helps illustrate the approach.

USER

_( > ( ) ( >_

\ ! /

\ ! /

I Transport ! Transport ! Entity i

i

i

i Layer 1•

i

i ii

: x sy

< > ( >

i / p

nr I# !

1 Network 11

1

1 Network I Entity 1

1 Vendor

Layer 1 1

1i

• a !b

( ) ( ) Station S: Globally Assigned

Link Service Access Point

Layer

1 z

( )_

/

S

I

•

II !c

( )

The transport entity x is addressed S.a.

The transport entity y is addressed S.a.p.

The transport entity z is addressed S.c. _

15
The suggestion was made to ask IEEE 802 for a Link Service Access Point LSAP

"a" pointing to the null ISO network entity. Since the Network Entity is null,

we assume it points to the Network Service Access Point "x." We assume that

other non-null ISO network entities will contain mechanisms for pointing to other

Network Service Access Points "y" and "z".

The TSAP identifier pointing to the USER is specified in the CR suffix parameter.

The participants agreed to use an ASCII character string to represent the TSAP.

The first octet of the string would be all zeros followed by an even parity "NBS..."

With consensus reached on addressing, Mr. Graube began a discussion on possible

applications for the 1984 multivendor demonstration.

For each identified application, the interested companies were identified and

tabulated as indicated below:

APPLICATION INTERESTED

ORGANIZATION

Messaging 3COM, DEC,

NBI

ASCII File Transfer Ford, DEC,

TEC

ASCII on top of transport Ford

U-B

X.29 ICL

Teletex ICL

File service (binary) DEC, Boeing

Phone DEC

5. Future plans

The next workshop is scheduled for May 5 and 6, 1983. It was obvious

that the identified applications require a thorough "flushing-out".

Specific application protocols neet to be defined. It was agreed that

application proposals and specification of application protocols would

be an agenda item at the next meeting.

16
NBS-H4A (rev. 2-80

U.S. DEPT. OF COMM. 1. PUBLICATION OR 2. Performing Organ. Report No. 3. Publication Date BIBLIOGRAPHIC DATA

REPORT NO.

SHEET (See instructions) NBSTR 83-2673 February 1983

4. TITLE AND SUBTITLE

Proceedings of the First LAN-Transport Workshop

5. AUTHOR(S)

6. PERFORMING ORGANIZATION (If joint or other than NBS. see in struction s) 7. Contract/Grant No. NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE «. Type of Report & Period Covered

WASHINGTON, D.C. 20234

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State, ZIP)

Institute for Computer Sciences and Technology

National Bureau of Standards

U.S. Department of Commerce

Washington, D. C. 20234

10. SUPPLEMENTARY NOTES

_2) Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bibliography or literature survey, mention it here)

The National Bureau of Standards Institute for Computer Sciences and Technology (ICST)

has prepared specifications for the International Organization for Standardization's

(ISO) Class 4 Transport Protocol. At the request of a number of companies, ICST

organized a workshop for local area network implementors of these specifications.

The workshop focused on implementation techniques and strategies so that a multi

vendor demonstration of these protocols can occur at a major computer conference

in the 1984 time frame. This report documents the workshop and records implementation

choices and agreements made by the participants.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolons)

communication protocols; computer networks; local area networks; standards;

transport protocol

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