REFERENCE

JUTTED STATES •ARTMENT OF jMMERCc

IBUCATION

^f°^

''•'Who*

NBS TECHNICAL NOTE 799

loo

15153

U.S.

ARTMENT

OF

MMERCE

National

Bureau

of

Standards

User Procedures Standardization

for Network Access

BTBureau of Standards

V 8 1974

-i wefi•

\0C> User Procedures Standardization

for Network Access

A. J. Neumann

Systems Development Division

Institute for Computer Sciences and Technology

(J ,^ t National Bureau of Standards

Washington, D.C. 20234

t.T

toXuvmuxty v\o\e- *yo> " i

Sponsored by

The National Science Foundation

18th and G, Street, N W. Washington, D.C. 20550

I

*'»a,u <* *

U.S. DEPARTMENT OF COMMERCE, Frederick B. Dent, Secretary

NATIONAL BUREAU OF STANDARDS, Richard W. Roberts, Director

Issued October 1973
National Bureau of Standards Technical Note 799

Nat. Bur. Stand. (U.S.), Tech. Note 799, 43 pages (Oct. 1973) CODEN: NBTNAE

For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 (Order by SD Catalog No. C13.46:799). Price 70 cents.
FOREWORD

This report is one of a series of publications

produced by the Institute for Computer Sciences and

Technology, National Bureau of Standards, under Grant

AG- 350 from the National Science Foundation.

This grant supports a broad program of research into

the foundations of computer networking in support of

scientific efforts.

A listing of completed and planned publications

produced by the Institute under this grant follows:

1. Primary Issues in User Needs

D. W. Fife

Chapter 10 in Networks for Research and Education:

Sharing of Computer and Information Resources

Nationwide

MIT Press, Cambridge, Mass.

Expected Publication October, 19 7 3

2. Some Technical Considerations for Improved Service

to Computer Users

T. N. Pyke, Jr.

COMPCON, 19 7 3 Seventh Annual IEEE Computer Society International

Conference

3. Computer Networking Technology - A State-of-the-Art

Review

R. P. Blanc and T. N. Pyke, Jr.

COMPUTER Magazine

Computer Society of the IEEE

4. Review of Network Management Problems and Issues

A. J. Neumann

NBS Technical Note 795

October, 1973

5. Annotated Bibliography of the Literature on

Resource Sharing Computer Networks

R. P. Blanc, I. W. Cotton, T. N. Pyke, Jr. and

S. W. Watkins

NBS Special Publication 384

September, 1973

6Network Management Survey

I. W. Cotton

NBS Technical Note

Fall, 19 7 3

iii
7. User Procedures Standardization for Network

Access

A. J. Neumann

NBS Technical Note 799

October, 1973

8. Review of Computer Networking Technology

R. P. Blanc

NBS Technical Note

Fall, 1973

9. Microeconomics and the Market for Computer Services

I. W. Cotton

Submitted to Computing Surveys

10. Cost Analyses for Computer Communications

R. P. Blanc

NBS Technical Note

Fall, 19 7 3

11. Network User Information Support

A. J. Neumann

NBS Technical Note

Fall, 1973

12. Quality Service Assurance Experiments

R. Stillman

NBS Technical Note

Fall, 1973

13. A Guide to Networking Terminology

A. J. Neumann

NBS Technical Note

Fall, 19 7 3

1M-. Research Considerations in Computer Networking

D. W. Fife

NBS Technical Note

Fall, 1973

IV
CONTENTS

Page

1.0 Introduction 1

2.0 Functional Summary 2 2.1 Initialization of User Access 2 2.2 Establishing a Communications Channel ... 4

2 . 3 User Identification 4

2.4 Authorization and Access 4

2.5 Obtaining Status Information 4

2.6 Computer and System Selection 5 2.7 Completion of Login 5 2.8 Logout 5 2.9 Accounting Data 5

3.0 Message Types and Procedures 6

3.1 Informational Messages 6

3.2 Command Messages 6 3.3 Special Command Signals 6 3.4 Message Sequencing 6

3.5 Degree of Interactivity 8

4.0 Comparison of Systems 8 4.1 Initialization "9

4.2 Establishment of Data Channel 9 4.3 Initial System Messages 10

4.4 User Signal 10

4.5 System Signals 10

4.6 Identification 10

4.7 Authorization and Access 11

4.8 Resource Selection 11

4.9 Logon Statistics 11

4.10 Logoff Statistics 11

4.11 End Message 12

4.12 Sequencing and Format Options 12

4.13 Default Procedures 12

5.0 Standardization of User Procedures 13

5.1 Need for Standardization 13

5.2 Standardization Criteria 14

5.3 Standardization Possibilities 14

17 Conclusions ... 35

6.0

7.0 References

v
FIGURES

Page

1. Network Access Subsystems 3

2. Message Types 7

3. BASIS Protocol Analysis (System A) 19

4. BASIS Protocol (System A) 20

5. GE MK II Protocol Analysis (System B) 21

6. GE MK II Protocol (System B) 22

7. INFONET Protocol Analysis (System C) 2 3

8. INFONET Protocol (System C) 2 4

9. MEDLINE Protocol Analysis (System D) 25

10. MEDLINE Protocol (System D) 26

11. NIC/ARPANET Protocol Analysis (System E) 2 7 12. NIC/ARPANET Protocol (System E) 2 8 13. SPIRES Protocol Analysis (System F) 29

14. SPIRES Protocol (System F) 30

15. Login Sequence Errors (INFONET) 31

16. User Command Data Elements 32

17. System Messages Data Elements (I) 33

18. System Messages Data Elements (II) 34

VI
USER PROCEDURES STANDARDIZATION

FOR NETWORK ACCESS

A. J. Neumann

User access procedures to information systems

have become of crucial importance with the advent of

computer networks, which have opened new types of

resources to a broad spectrum of users. This report

surveys user access protocols of six representative

systems. Functional access requirements are outlined,

and implementation of access procedures is analyzed

by means of a common methodology.

Qualitative assessment - of standardization

possibilities identifies standardization candidates

such as: system and user signals, on-line user

entries, system requests, and network wide categories

of message content.

Key words: Network access procedures; networking;

standardization; user protocols.

1. INTRODUCTION

User access procedures to information systems (user

protocols) are concerned with all actions a network user

has to perform to be able to use the facilities offered by

the network. These access procedures have become of

crucial importance, especially since computer access no

longer is the exclusive province of the computer operator

or programmer. It is now available to many users, to

computer specialists as well as to members of other professional groups interested in research and routine

operations

Access to computers is enhanced by the development of

networks. Remote users, with a relatively inexpensive

terminal, can now have access to a variety of computer

resources on a country-wide basis. As computer systems have

proliferated, so have methods of access. The present state

of the art is one of great diversity, so much so that the

large variety of access methods often makes it difficult for

the user who is looking for simple, uniform, and reliable

access methods, yet wants to use diverse resources. Ideally,

therefore, access should be similar to that used for worldwide telephone networks, where simple, uniform dialing

devices, procedures, and numbering schemes facilitate

operation.

This study is concerned with a description of access

(and exit) mechanisms, as the user sees them. Some
conclusions will be then offered as to possible directions

for standardization, which may help to unify procedures,

and aid the user in access to these systems. The immediate

task of this report is to collect data on access mechanisms

with a view to providing a basis for further work in planning, developing guidelines, and possible standardization

efforts

2. FUNCTIONAL SUMMARY

An access procedure, as seen by the user, consists of

a series of data entries into the system and of observation

of data outputs from the system, or reactions by the system.

These actions follow each other in a predetermined manner

and continue until the access procedure is completed.

The point of contact for the user is a terminal which

provides keyboard entry and display capability. Display

may be in the form of hard copy, or it may be volatile,

such as on a cathode ray screen. There are several

distinct phases of access which depend on both the characteristics of communications and computer hardware, and on

the requirements for access control, handling of traffic,

accounting and billing, or control of proprietary information. Figure 1 illustrates a functional breakdown of

subsystems. It shows user data terminal equipment, communications equipment, communications circuits, and a host

computer providing an operating system, user languages and

application packages. The communications channel may

include computers, such as communications computers and

interface message processors. Terminal equipment in

addition to an operator terminal may provide computing

capability.

The various phases of access are: initialization,

establishment of a data transfer channel between

communications equipments, establishment of a data link

from terminal to the host computer, which results in

computer access and the operation of the working program.

Included also must be procedures required for reversal of

the process, including program exit and shutdown of the

source data terminal equipment.

2.1 Initialization of User Access

The process of accessing a computer network starts

with the preparation of communications equipment by the

operator. Power for the terminal proper and ancillary
USER

TERMINAL

DTE

DCE

-CCT

DCE

COMMUNICATIONS

COMPUTER

DCE

^CCT

DCE

DTE/HOST COMPUTER

. OPERATING SYSTEM

. WORKING SYSTEMS

. LANGUAGES

CCT = Communications Circuit

DCE = Data Communications Equipment

DTE = Data Terminal Equipment

NETWORK ACCESS SUBSYSTEMS

Fig. 1
devices, among them acoustic couplers, are turned on.

Where a choice of terminal speeds is available, the proper

speed is selected. Similarly, a communications mode (half

duplex, full duplex) and other terminal options must be

selected and, in turn, activated.

2.2 Establishing a Communications Channel

Next, a communications circuit is established between

the user's terminal equipment and the equipment at the host

computer. This mav be done by message switching or circuit

switching systems. User access is usually through a dialup connection but dedicated access channels are also

available.

In some networks, this process requires several steps:

first, a local communications computer is dialed, and

later a remote computer address is entered. This selects

and connects with the desired host computer. Establishing

the communications channel involves the recognition of the

terminal characteristics in terms of terminal speed,

character set, and communications mode. Though there are

some systems that provide automatic terminal recognition,

in many cases the user assists in the process by transmitting a terminal identification code. A few communications computers perform user identification and access

control, but this is normally done by the host computer.

2.3 User Identification

User identification, for both accounting and access

control purposes , requires the operator to enter some

special information. Usually, such entries involve a user

number, password, project number, personal identification

code, or similar information. Most of this information

is entered by keyboard action in a character-by-character

mode

2.4 Authorization and Access

Based on the information supplied by the user, the

system validates his access request, and authorizes access

to the system. In cases where invalid passwords and/or user

numbers are detected, user access is terminated.

2.5 Obtaining Status Information

At some time during the access sequence, the user is informed of the network status. He may be told of the present
configuration, the latest software version in use, the port

number, concentrator and remote concentrator numbers. He

is also informed of planned shutdowns or intended system

changes. In addition the operability of the system is

often indicated by a "greeting message," including date,

time, and other accounting details.

2.6 Computer and System Selection

A common task of interest to the user is the selection

of the computer site, if he has a choice of more than one.

Further decisions must be made regarding desired computational or information processing programs and processes.

For these purposes, the user enters a site address and

various codes referring to the systems to be accessed.

2 .

Completion of Login

After the access sequence is completed, the system

sends a "system signal" to the user. This means that it

is ready for use. At this point, the user may access the

working system of his choice and begin operations.

2 .

8

Logout

The reverse procedure takes place upon leaving a

system. After the user indicates his desire to end operations , the system responds by transmitting data about

terminal time used, computer time used, and date and time

of logoff. Finally, an "end message" informs the user that

he has been duly logged out and that the system is disconnecting.

Usually the user must inform a hierarchy of systems of

his desire to terminate a session. These may include the

working system, the host operating system, and the

communications computer. There are, however, instances

where this sequence has been simplified so as to permit

logout by only one user command.

2.9 Accounting Data

At the end of the terminal session, the user receives

usage measurements. They include time measurements and

amounts of storage which record used resources. As a rule

this is part of the logoff procedure. These measurements

are reported together with the appropriate user and

account number, to assist him in managing his own resources

and results.
3. MESSAGE TYPES AND PROCEDURES

The access procedure thus consists of an exchange of

actions and reactions between the user and the terminal,

which represents the total system to the user. Messages exchanged during the access protocol may be of an

informational type or of a command type. Commands from

the user to the system are called system commands, or user

commands. Messages from the system to the user are called

system requests, or system messages. Figure 2 summarizes

the various message types.

3.1 Informational Messages

Informational messages convey required data to the

user, or to the system for purposes of accounting, usagemeasurement, or system performance measurement. Typical

messages of this nature deal with time, date, location,

system status, expended resources and system characteristics .

3.2 Command Messages

Command messages, on the other hand, require immediate

action, either on the part of the system, or on the part of

the user. Typical action commands are system requests

like: "LOGIN PLEASE," or "USER NAME" or commands to the

system such as "OFF" or "QUIT," which are used by the user

to terminate operations. Identification data also fall

into this category.

3.3 Special Command Signals

Two kinds of signals merit special mention: the "user

signal" and the "system signal" named by Little and

Mooers (l).1 The user signal is entered by the terminal user

to denote that his immediate task of data entry is finished

and that he is waiting for system action. Likewise, the

system signal, which is produced by the computer, tells the

user that processing is completed and that the next step

is up to him. In interactive processing, these signals

are used most frequently, and thus play a special role.

3.4 Message Sequencing

Diversity of system access procedures exists in the

variety of data elements contained in the informational

and command messages. In addition, sequencing of the

1 Figures in parentheses indicate the references at the end

of this- paper..
1 /"N ^ CO ft

^-N CO CO CO CO rd ^^ rd p 4-> -P

v_y

ft < ft

J

O -• 53

O -• < -a ~ CD TD

— S a) a) "O H CD CD TJ

CD Mft CD CO bO^ CD H rd co a) rd CO CD CO CO «H O

co

C

O

gw

CO -H

O

co £ O

co Bi CD -H ft Eh CD -H ft W w £ ft Oh CO £ ft ft CD CO >H < P • CO • CO

co

id

CD

W ^^ £ ft g o <d £ •H p -M CD 3 ^^ Q \w/ CO +-1 a1 ft ft CO S >1 CO CD CO CD CD g Q CO >>

CO

ft ^> CO ft 3-H

g o >> Eh 3 o 2 -H ft H CO ft & o g o +J H W O CD o a) T-i rd P ft ft o > CD ft ex CD ft •h rd CO 4-> 3 ft +-> *> co O ft H C CO TJ ft co C c H o o O CD CD CD O O g co CD TJ ft 3 O g 3 ft ft H P in co cr1 O H c^-H co EH •H CD CD ft Eh CD O CD CO T3) -H ft in ft CO ft rd ft >H >H

CO • « • CO •

^\

y^^

g

g CO P 6 ^>

v_/

H CD rd -l-J

w

H

w

C co CD rti ft s CD O >> < C cu o < •H CO CO O CO

l-H CO +J CO •H 3

E-h CO CO rd

O

H -P < w H e -p g rd

O

g CD

g ft 6 -H P^ < O +J g ft O CO ft ft X W O +-» ft CO H C <D EH ft X s w CO •H +J CO C CD H Si p • CO •H -P g ft w W

Eh CO

COp ^

CO o

Eh

Q

EH

g

Pi Eh pa CO CO >H P ;

CO

MESSAGE TYPES

Fig. 2 7
various elements involved in the access, i.e. , the access

sequence syntax, must be considered. The latter contains

both system messages and user messages.

3.5 Degree of Interactivity

Depending on their objectives and skills, users' needs

differ as to their degree of freedom in system access. A

novice user appreciates detailed step-by-step prompting

from the terminal. It is equally important to him that he

be able to put in his reply on a simple step-by-step basis,

while the experienced user may be willing to trade time and

complexity, requiring a minimum of guidance from the terminal. For these reasons , most systems provide several

access alternatives at the user's option.

Access pro

have been analy

in this analysi

three data base

and one node of

CA) , GE MK II ( ARPANET (E), an

and letter code

features. to the

analyses on pag

4. COMPARISON OF SYSTEMS

cedures for a few representative systems

zed and results are reported here. Included

s were two commercial time sharing systems

,

oriented information retrieval systems,

the ARPANET. The systems were: BASIS

B), INFONET CO, MEDLINE (D) , NIC/

d SPIRES (F). The ordering is alphabetical,

s in parentheses are used to refer system

particular systems, and to the protocol

es 19, 21, 23, 2 5, 2 7,. and 29.

The analyses were limited to development of a uniform

methodology of description of data elements, element

sequencing, and of categorization into message classes.

User and system generated messages are considered.

Not considered were data element format details. Data were

collected by entering and leaving the systems under test, and

by printing out the access protocols on a teletypewriter.

These printouts are shown in Figures 4 , 6, 8

, .10 , 12, 14,

and 15

Each protocol was then analyzed as to message type and

sequencing. These analyses, in a uniform format, are

shown in Figures 3, 5, 7 9 9 } n } and 13.

The following conventions have been observed in

documenting the access sequences for the various systems.

A serial number denotes the position of each data element

in the access sequence. The sequence is characterized by

four types of messages: system message (SM) , system
request (SR), user message (UM) , and user command (UC).

The system signal is denoted by (SS), while the user signal

is denoted by (US). Message categories are denoted by

capital letters. Marginal comments are in standard upper

and lower case. End of the login sequence is shown by a series of dashes. Several message elements printed on the

same line have their own sequence numbers. The logout

sequence starts after an appropriate systems signal.

Comparison of user command and system message data

element categories and data element sequencing are shown

in Figures 16, 17, and 18. Numbers in the boxes of the

tables refer to the individual analyses, and indicate the

ordering of the elements.

Results were not correlated with pertinent systems

documentation, nor have all possible variants of display

formats and message sequencing options been explored. The

examples cited are however representative and serve the

purposes at hand. Discussion of access sequence details

follows in the next sections.

4.1 Initialization

In this experiment, a typewriter- like terminal with

hard copy output was used/ It was connected to_the Bell

Telephone System through an acoustic coupler. Initialization here involved turning both coupler and terminal power

to "on," and setting of the coupler mode to either "duplex"

or "half-duplex. " Other terminals may have different and

additional initialization requirements.

4.2 Establishment of Data Channel

Access to systems was through the Bell System. In

some cases access is via long distance connections (A)

,

while in the case of ARPANET a local communications computer

(Terminal Interface Processor, TIP) provides network access

as well as common carrier switching control for remote

computer access (E). Various means are used to indicate to

the user that communications have been established. A

system request "PLEASE TYPE THE LETTER D" (D), a system

message giving configuration code, time and time zone,

and date, or no reaction at all, are typical cases. In the

latter case operating procedure requires that the user

enter a terminal recognition code, which elicits the first

system response (E). If , as in the ARPANET, more than one

computer is involved, a hierarchy of communications protocols is required, i.e. user to TIP, TIP to host and
finally user to host. After receipt of the systems message

from the TIP, and selection of the host address, a system

message indicating communications status confirms completion of the data link (E)

4. 3 Initial System Messages

A variety of system messages indicate that the data

link has been completed, and that terminal to computer

connection has been established. Such messages range from

a mere "HELLO" (E), to more complex messages giving .terminal identification codes, date and time messages CO, as well as messages indicating location, date and time CF).

Other initial system messages give system and communications status (E), and identification of systems software

(E) (A), equipment and port designations CO.

4.4 User Signal

User signals vary from system to system. On the

ARPANET several different user signals are being used to

enter a remote host. Entering of the host address, identification sequence, and working system code require depression of one terminal key, the "line feed" character.

Working program exit requires actuation of two keys,

"control," and "D. " Other user signals are "carriage

return," "new line," and "control, S" (F).

4.5 System Signals

Completion of a system action is indicated most often

by a "carriage return" following a "line feed." In addition

often a "prompt" signal indicates that the system is ready

for user entry. A variety of symbols are used for this

purpose such as: the 'at" character "@" CE), exclamation

mark "J" CO, and question mark "?" CF). Other systems

use words like: "COMMAND" (A) , "USER" CD), or "READY" CB)

4.6 Identification

An identification request is sometimes implied by

system requests like "PLEASE LOGIN" (A) or "LOGON" CO.

In other cases identification is required by standard

operating procedure, where the user, upon receiving the

initial message and a prompt signal, enters his identification data, like user number, password and identification

code (E). Some systems request identification detail

explicitly with system requests like "PASSWORD," or "USER

10
NUMBER" (B) (C). Password protection is obtained by

non-printing (E) (D) , or by underprinting (A) (B). Other

detail required are organization codes or account numbers,

and personal identification codes (E).

4.7 Authorization and Access

Invalid passwords or user numbers, like format errors

in entry of identification data may lead to repeated

system requests for login, or result in the disconnection

of the system. Figure 15 shows several user numbers which

were unacceptable to the system because of format error,

and brought about the subsequent disconnection of the

system.

4.8 Resource Selection

In the ARPANET, indications of the host address code

"L 2," initiates the establishment of a connection between

the user and the remote host (E). After receipt of the

greeting sequence and of completion of LOGIN, the selected

program is indicated by inserting the proper code.

In the GE MK II system, the system long form version

may request the programming language and the file to be

used. In the sequence shown here, the user selects

files and languages after being put into the READY

condition (B).

"4.9 Logon Statistics

Some systems provide a "logon date" except (D) and

CB). They also indicate logon or contact time. One system

provides both: contact time for the first system contact

and logon time for the actual system access (A).

4.10 Logoff Statistics

All logoff statistics provide time and resource

usage information in all cases except one (D). That

system apparently is of an experimental nature, and

metered user charges are not used. (B) includes the time zone,

The ARPANET furnishes additional information, including

a job number, user number, account number, as well as a

terminal number (E). Other systems account for System

Resource Units "SRU" used (C) or for Computing Resource

Units used "CRU" (B).

11
4. 11 End Message

Two of the tested systems conclude with a final system

message: "GOOD BYE" (C)"and "END OF SESSION" (F).

4.12 Sequencing and Format Options

Most systems provide several format options. Sequence

formats vary from a completely "interactive mode," where

each data element is entered separately and evokes a system

request for the next data element, to a "terse sequence,"

where all data elements are entered sequentially, separated

only by the proper syntax separator (space or comma). In

the interactive mode there are variations among the

systems. The system response may be a system signal, or

it may also be an explicit request for the next data

element, as illustrated by one commercial system which

calls for user number and password as the initial logon

step. In that system, this information may be entered

as

(user number ) (comma) (password) (user signal)

and will elicit a request for "project identification." A

permissible variant in that procedure is to follow the

sequence of:

(user number ) (comma) (user signal)

This will automatically provide an explicit request for the

password. When given, the password is then automatically

obliterated by a dense character field, thus shielding it

from human view, yet permitting machine recognition. An

example of an interactive, prompting sequence is shown in

Figure 12

4.13 Default Procedures

User errors in entering logon data elements are

generally handled in different ways . In the extreme case

,

an error might disconnect the system and require reestablishment of communications and of the login process. On

the other end, user errors would be interpreted by the

system and corrective system messages would provide guidance

The systems examined here operate somewhere between these

extremes

Common user errors occur through the omission of space

characters where required, through the use of wrong

12
separators (comma instead of space character), or through

the entry of the wrong sequence of data elements. Usually

the systems react by printing repeated requests for logon

and then by system cutoff, after a specified number of

attempts to enter the system have been made. Figure 15

shows reaction of one system to erroneous data entry.

After two attempts of entering a wrong user number with

syntax errors (omission of space character, and substitution

of zero character for the alphabetic character 0) and two

requests for LOGON the system disconnected.

The preceding discussion illustrates the variety of

message elements and procedure which make up the user

access sequences for the various systems. Indications are

that technical changes will continue, although functional

requirements appear to be relatively stable. Possible

standardization efforts must take the functional needs and

the rapidly changing technology into account.

5. STANDARDIZATION OF USER PROCEDURES

Standardization of user procedures presents many

problems. For this reason, there must be a compromise

between ideal requirements and the capabilities of

those concerned with implementing them. This is particularly true when time, personnel, and financial resources

are limited. Requirements are based on the user's needs,

while implementation of requirements needs to follow a

course that will produce the most desirable features with

limited resources.

There also is the question who should develop the

standards, private industry or government, and the question

of how badly a particular standard needs to be developed.

Early standardization in a developing technology may

inhibit progress , while lack of standardization may lead

to a proliferation of non- compatible features. In the case

of network access procedures, this may impact adversely

on ease of computer access and use. Standardization efforts

must also be concerned with the costs which might be

incurred by the systems, which may want to adopt proposed

standards

5.1 Need for Standardization

The need for standardization in network access

procedures has been recognized by users of timesharing

systems for some time, especially by those who use different

systems alternately. The need is now being accentuated

13
with the advent of networking capabilities, where data

requirements are increasing for identification, authorization, accounting, and data protection. At the same

time, network communications computers, more than ever

before, must recognize a great variety of terminals and

terminal options, and both terminal facilities and host

computers must interact with communications protocols of

greater complexity to an ever increasing extent.

5.2 Standardization Criteria

Since the standardization process is slow and time

consuming, standardization objectives must be carefully

determined. These are some criteria, on the basis of which

goals may be established: (1) frequency of usage of

item to be standardized; (2) commonality, and (3) required

precision.

Data elements, or message representations frequently

used by many users would, if standardized, provide ease

of use and reduction of user errors. They would also

enhance the operation of the system. Therefore, system

messages to users from different systems having the same

meaning should also have identical representations.

As an example, the use of a question mark, asterisk, dash,

or other graphic symbol as a system signal adds to user

confusion and dissatisfaction, when meanings in the various

systems differ. Further, in cases where precise user

input for machine recognition is required, format standards

would improve system operations. On the other hand, system

messages of an informational nature, not requiring immediate

user action, may be in free format, and their design is

governed by the basic rules of grammar and by readability

considerations

Common use of symbols requires uniformity, not only

for machine-readable data but for concepts and human

readable information as well. Categories of access,

accounting classifications, and types of malfunctions, for

instance, need to be described and categorized clearly and

uniformly if inter-system operation between various

services is expected in the network environment.

5.3 Standardization Possibilities

Opportunities for standardization of access procedures

exist in the areas of: message content categories, types

of messages, message formats and sequencing, and descriptive terminology.

14
5.3.1 Message Content Categories . Standardization of

message content is desirable as it relates to

classification schemes which are descriptive of

message content, such as data descriptions, file

descriptions or program descriptions. Likewise

network statistics and measurements depend on the

classification of system characteristics of equipment and of software, just as accounting procedures

depend on the structure of accounts.

5.3.2 Types of Messages . The first candidates for

standardization of message types would be the

user and the system signals. Their meanings

are unambiguous and precise, they are the ones

most frequently used on all systems. Uniformity in the meaning and use of these signals

would help the use of multiple systems. Next

in line would be "on line user entries," i.e.,

user commands (system commands) requiring

precise machine interpretation and reaction.

Similarly, system requests addressed to the

user require precise reaction by the user and

could be standardized. Also, the standardization of user entered informational messages is

of importance from an overall systems standpoint. Though they do not affect control

operations, uniformity in inter-systems accounting, access procedures, and statistical data

collection is required. Similarly system

messages , in coded form require standard

definitions to be universally understandable.

Some beginning has been made in standardization

of control elements. Little and Mooers (1)

have defined twelve universal user control

actions, and have suggested the assignment of

standard symbols to these actions. Additional

actions will be required for network operations.

Standardization at this functional level

appears practical and desirable. There is an

interaction with existing information exchange

codes (ASCII Code) (3) which also provide for

control characters. They do not cover all

needed functions , but standardization of additional functions is in progress. Terminal

access standards development needs to be

closely coordinated with this work.

Standardization of informational data elements

is a more difficult matter. Some beginning in

15
this area has been made, and continuation and

coordination is required. A standard for date

representation has been developed (8) and acceptance

of a standard similar to the date-time group in

military communications can be envisioned.

Other standard designations might be developed

for resource center locations (along the lines

of the three character airport codes) for

computer system configurations, and for software designations. Uniformity of definitions

would permit meaningful exchange of operating

statistics and correlation of system performance

parameters. Other data elements that might be

candidates for standardization are those pertaining to system characteristics and error

taxonomies

5.3.3 Format Standardization . Format standardization

may occur at several levels. On a higher level,

an entry procedure consists of a series of

interconnected messages. Their sequencing may

be arranged in different ways according to ease

of use from the users' viewpoint, or according

to the ease of processing from the systems'

viewpoint. On the level of individual messages,

or words, format considerations arise and need

consideration.

5.3.3.1 Message Sequencing . Figures 16, 17, and ]_8

show that , although there is some agreement

among data elements entered into and received

from the systems , there is little uniformity

in the sequencing of data elements within the

access procedures. Just as in international

telephone dialing, where a country code is

selected first, followed by an area code and

some local digits — which represents a hierarchy of switching facilities -- a general

conceptual ordering of access information

appears feasible. No recommendation or suggestions

on how to achieve this can as yet be made, but

the topic of sequencing merits further consideration, from the standpoint of both the user and

the system whose software must process these

messages

5-3.3.2 Word Formats . Then there is the issue of

word formats which directly relate to the

ability of a system to recognize and respond

to its inputs. Such details as punctuation

16
marks and space characters which may appear

trivial to the user, often have syntactic

meaning to control software. Though of no

interest to the human reader, their use must

be precisely specified.

Little and Moers have taken a dim view of

format standardization, stating that "since

data formats have a potentially infinite

variety, it is futile to consider the standardization of formats themselves." CD. They

propose instead the standardization of data

descriptions, the logical development of

elements of format generation, and finally a standard method of describing external data

formats for entry and display. Nevertheless,

it is believed that some format- related

standards might conceivably be developed and

would find general acceptance.

5.3.4 Descriptive Terminology . Related to standardization of message types, content, and formats,

is the descriptive terminology which is a necessary adjunct to standardization. Terminology needs to be unified, especially since

technical considerations of network entry

procedures involve such varied fields as data

processing, telecommunciations , linguistics,

computer sciences, and other engineering and

human oriented disciplines.

6. CONCLUSIONS

User network access protocols are becoming of increasinj

importance in utilization of emerging computer networks.

Standardization is required in some critical areas and will

have beneficial aspects, in terms of user productivity and

economics of network operations and utilization.

Standardization has been effected for keyboards (6),

(7), but extension towards new requirements for user control

of networks need to be added (2). Standards exist for data

elements, such as calendar date ( 8 ) , and states and counties

of the United States (9), (10). Again there is further

need for networking oriented effort.

Work is also underway to develop a unified language

for describing technical concepts, hardware and software

functions, and overall systems performance (M-) (5). While

17
this work is in progress, it needs the support of all those

engaged in developing systems standards for network access.

Additional definitions are needed in the specific area of

access protocols and these definitions need to be integrated

into network procedure standards efforts. It is essential

that a common language be developed not only to simplify

user operations but in support of training, maintenance,

and the interchangeable use of common network resources.

In summary, it is concluded that there is need for

standardization, that there are definable tasks to be undertaken, and that a standardization effort in user access

protocols would well be worthwhile.

Such an effort must however be quite broad, consider

existing and planned industry activities , economic impact

on user and manufacturers, transitional problems, and

relationships to existing and planned standards in related

areas

18
1,2 SM "BATTELLE INTERCOM 4.0"

3 SM DATE

4 SM TIME

5 SR "PLEASE LOGIN"

6 jucj "LOGIN"

7 SR "ENTER USER NAME"

8 jucj USER NAME

9 SM "HBHHHHH"

10 SR "ENTER PASSWORD"

11

f|UC: PASSWORD

12 SM SPACE

13 SM DATE

14 SM LOGIN TIME

System, Version No,

Underprint

15 , 16 SM EQUIPMENT NUMBER/PORT NUMBER

17 SS "COMMAND"

18 jUC "LOGOUT"

19 SM COMPUTE TIME

20 SM PP TIME

21 SM CONNECT TIME

22, 2 3 SM DATE, LOGOFF TIME

BASIS PROTOCOL ANALYSIS (SYSTEM A)

Fig. 3

19
BATTELLE INTERCOM 4.0

DATE 05/15/73

Tlfl£ 15..39. 15.

PLEASE LOGIf^

LOGIN

ENTER USER NAME- S1AN3S013

ftssseaasss enter password05/15/73 LOGGED IN AT 15.40.18

WITH USER- ID RO

EQUIP/PORT 77/50

COMMAND- BASIS

BASIS 70

DO YOU DESIRE OPERATING 1 NSTRUCTI ONS\

TYPE YES OR NO/NO

PLEASE ENTER YOUK LAST NAME. /NEUMANN

ENTER THE NAME OF DATA BASE TO BE SEARCHED.

/ N T I S

ENTER YOU* SEARCH ONE TERM AT A TIME.

1/ QUIT BASIS 70 HAS

ENJOYED SERVING YOU.

DO YOU HAVE ANY COMMENTSX

YES-NO/NO

CDONT FORGET TO #LOGOUT.# BEFORE DISCONNECTING.)

GOODBYE

END BASIS

COMMAND- LOGOUT

CH TIME .203

/JP TIME ^.692

CONNEC T T I M E HK S . 2 M I N . B6/lb/73 LOGGED OUT AT 15.42.08.<

BASIS PROTOCOL (SYSTEM A)

Fig. 4

20
1 UC TERMINAL RECOGNITION CODE

2 SR USER NUMBER REQUEST

3,4 UC "USER NUMBER," "PASSWORD"

5 SS "READY"

6 UC "BYE"

7-9 SM COMPUTING RESOURCE UNITS, TERM. CONNECT TIME

THOUSANDS OF CHARACTERS STORED

10-12 SM LOGOFF TIME, TIME ZONE, DATE

GE MK II PROTOCOL ANALYSIS (SYSTEM B)

Fig. 5

21
H

U#=aek73105,

READY

bye

0000.03 CRU 0000.01 TCH

OFF AT 15:30EDT 08/21/73

0000.03 KC

GE MK II PROTOCOL (SYSTEM B)

Fig. 6

22
1 SM Itmli Communications

2 SM SPACE Format Feature

3 SM PORT NUMBER

4 SM CENTER ID

5 SM SPACE Format Feature

6 SM TERMINAL ID

7 SM DATE

8 SM TIME

9 SR "LOGON?"

10 UC SYSTEM CODE

11 SR "USER ID"

12 UC' USER NUMBER

13 SR "PASSWORD"

14 uc! PASSWORD

15 SR "PROJECT CODE"

16 UC'

i PROJECT CODE

17, 18 SM UPDATE NOTICE ANNOUNCEMENT, DATE

19 SS t? t "

20 ucj "OFF"

21, 22 SM USAGE ON DATE AND TIME

23, 24 SM SRU / ELAPSED TIME

25 SM "GOOD BYE.

INFONET PROTOCOL ANALYSIS CSYSTEM C)

Fie;. 7

23
PORT: 6 4

CENTER: 8B

TERMINAL 1071 0S/15/73 13:00:43

LOGON: GPS

USER-ID: UBS002

PAS S W OR D : -

PkOJ CODE: 640090 1 ADM999 1 EDI F/L INFORM 5/14/73

•OFF

USAGE ON 05/15/73 AT 13:02:10

SRlTS:.8 ELAPSED TIME: 00:00:19

GOOD BYE.

CINFONET PROTOCOL (SYSTEM C)

Fig. 8

24
1 SR "PLEASE TYPE THE LETTER D"

2 UC "D"

3 SR "PLEASE LOG IN:"

4 UC USER CODE

5 SR "PASSWORD:"

6, 7 UC PASSWORD Cnon printing), ACCOUNT NUMBER

8 SM INTRODUCTION

9 SM REQUEST FOR FORMAT OPTION

10 SS "USER:"

11 :UC DISCONNECT COMMUNICATIONS

MEDLINE PROTOCOL ANALYSIS CSYSTEM D)

Fig. 9

25
Of. hi

tf) 31 a

Ul

3; o O 2

(- 2 UJ

UJ *—

to CO

UJ

or

UJ UJ in rt • _) < X > —

CD UJ UJ

u.

<r DC

:*:

_J s—

o z

<r <r

K > a <V n

UJ u3 fI—

UJ to UJ

C£ z "Dk

{- —I 1 UJ _1 ^ UJ K t—

Q

UJ2 a

UJ CO i—

z UJ x

*—i

a

X a: _] z E- <r Q <r o

UJ

X

~2L UJz

CO

1—

UJX

UJ

—

.^- fT" -J

J— UJ o

U3

1£ o s V —

fUJ o Q X a CO

UJ h»

a o • m

az

££ UJ UJ <Z <z UJ z 2; [-> H _j ,-t 2 >-H <r UJ t- i. 5> -£. S) o _1 a

UJ _1 CO -J co o Q

X

.J 2 no 2 m UJ CO o Z ^ CO £ r- UJ Q Q —

\ o 2 X •* U] • • UJ s .-< t— 2 5- t: 2; -J -1 UJ

i—•» >—••> <c z U! -* uj z. 2 5- a. a o *—

21 ~D f—

5- o •• o •• 2; o "3 H _j O -J a v a:

"£ ^\> UJ U. 2 C^ # UJ uj o UJ b h-

—

i— CO 71 3: CO ^ o <c <r •• <r <c •o <r CO 'O _J' — a. ."V uj UJ V) Ul co 1—4 _J z .-v UJ

_i -J <C _] <£

x fj

aO CO a. a. a. 0, a. Lm X o u, 3 QSW

En

c/J I*coooo

EhO

(XwHow

CDH

26
1 SM "HELLO 306"

2 jUC! "@L 2" Logon command, Host address no. 2 3,4 SM "LOGGER R OPEN T OPEN"

5 SM SYSTEM ID.

6 SM FACILITY ID

7 SM OPERATING SYSTEM ID

8 SS "@"

9 , 10 UC; USER NO/ACCOUNT NO

11 SR "IDENT =

"

12 'UC IDENTIFICATION CODE

13-16 SM JOB NO/ TT NO/ DATE/ TIME

17 SM STATUS MESSAGE

18 SS "@"

19 luCi ENTER

2 SS "*"

Identification request

21 UC "E L" Execute Logout

22-27 SM JOB NO/USER NO/ACCT NO/TT NO/DATE/TIME

2 8, 29 SM COMPUTE TIME / CONNECT TIME

30 SS "@"

31 IUC "C"

32, 33 SM "T CLOSED R CLOSED"

NIC/ARPANET PROTOCOL ANALYSIS (SYSTEM E)

Fig. 11

27
co

CO

CD

CS

CO(S

CO

fvO

COX

CO

H

CO _)

cos

OJ

co

CO

H 1 ss O 2 CV) <n

53 T3 CO

•JO "0 •» • 1 co a. •^ CO i

r—

o CO 1 tiJ vO T~ 00

X! NT 1 m

UJ >-

O z o (- a •V

1—

ui Ex] 30 z 2 ~£ ^0 0J \ o "D • • O z -< f£ CO ~i •» ••

Q < —• a f—c0

CO S3

U

'-.1 * m >-H

•7^ o z S o O X en I—

_J

Ld

M -) o ;'ii

h o o

0, • CO i—

"0 :0 o

CO Z o ^3 Q • £3

rr

sO !-• • a. < —I z Ul ••

Q

S> 1-1 >—

~- !x]

H 3 rj

:n z *-» It V) t- f— <r

'0 cc w X i (~ -< UJ 3 ~> z a o O ui a. UJ 00 2 'jj a O 3 i—

Ul -J _J CO o o ^ CD UJ z •/> a IJ a ;£ :0 o

_J o rj Z a rxi _i >< o a: "D

UJ _J o "C

H •—

t—

z o bJ _j (xJ

O f-»

r <S> _1 <2> c&

X * Gi> (— a>

wsH

CO

>h

COooo

EhO

PL,

EHH<

P^<o

CM

•H

P-i

28
1, 2, 3 SM STATION ID, DATE, TIME

4 SR "NAME ?"

5 UM NAME

6 SR "ACCOUNT?"

7 UC ACCOUNT NUMBER

8 SR "KEYWORD?"

9 UC KEYWORD

10 SR "TERMINAL?"

11 UC TERMINAL CODE

12 SR "COMMAND"

13 UC SYSTEM NAME

14 SM WELCOME ETC, NAME

15 SS M_ 9 II

16 UC "LOGOFF"

17 SM COMPUTE TIME

18 SM EDITING TIME

19 SM ELAPSED TIME

20 SM "END OF SESSION"

SPIRES PROTOCOL ANALYSIS (SYSTEM F)

Fig. 13

29
STANFORD 75 0!5/09/73 11:01:39

NAME? NEUMANN

ACCOUNT? 1067

KEYWORD?

TERMINAL? W99

COMMAND ? SPIRES

-WELCOME TO SPiaeS-2, NEUMANN

— v

-? LOGOFF

COMPUTE TIME =3.39 SECONDS

EDITING TIME = O.Ob SECONDS

ELAPSED TIMS = 00:16:47

END OF SESSION

SPIRES PROTOCOL (SYSTEM F)

Fig. 14

30
POrM": 64

GEN TEH: BB

TERMINAL 1233 05/15/73 13:04:55

LOGON: UBS002

LOGON: GPS

USER-ID: UBS 002

USER-ID: UBS002

GOOD-BYE

GOOD BYE.

PW

LOGIN SEQUENCE ERRORS CINFONET)

Fig. IB

31
11 1 r

GO ft w ft

ft CDO

H ft LD CD r- CO CO 6 CD

PL,

H o| rd

O

CO 2 ft . - £ <

ftft E < +J CD J \ w en CM o CM o ft CO XI o H H CM J o o w H

Iti

rd

ft o = HSM Pn CD J P J- CD c-- CM ft CD XI Q o CO O W P O S

EhW

g E 2 CD CD ft o o CM J" CD CD ft +-> X ft

ftH

HH

H o CO o S >>o £ H n HH X

CD CO

ft" •H ^ S ft CO J- fto H

ft

w

W 6 ft

CD

H

00

CD

H

CO = = H 2 Eh

CO < 00

H Pi

H P — < H o CD O CO

ft

— rH

O CDO

C X5

cy X)

C 3 rd

O o -P o •H CD >,

CD H->

C Pi CD s • rrj O X ft

fd bO

O •H CD CD

C 2 h

H H-> bO (D

H

O

O M-) rd rd ft

O

•H

H \ •H

O •H Ph

+-> rd

u +-> •H CD 6 Ph CD -P

rd 3 CD c ft

X CD Ph

CC

X rQ CD •H CO +J rd -H

O

•H Pn •H

R

X -P CO

O CO

O ftO

4h CD > 3 H

C CD >.

H 0) ,£} •H c CD Sh CD CO CD rH II

n

M -P 6 g XI X rH X XI CO ft CD rd C rd 3 fi & +-1 rd H X rd bO >^ bO C ft ft CO,

CD 2 2 H

O c a < pq c Eh rd bO

O

J ol

id 5 3 •H CD •H 3 •rH H in P-J P-i CO O 6 O H-> rd ft CD bfl CO Eh

0) CD CD CO o Ph •H CO +->

h

H c 2 P ..

k CO CO CO rd CD > o rd

O •rH rd | Ph

H o CD

0)CO D

D

p

D ft < Eh in

CD CO

HI ft & ft

J ' CD CD CDO

ft

+J

UJ P o2

USER COMMAND DATA ELEMENTS

Fig. 16

32
SPIRES F 00H

O Ph w

h pi; H

MEDLINE D oo

W

2O o P-i

i S

H

1-8

H

H PQ pa «

CD S

00H

CO <

<

CQ

LOH

C

O

•H

-PO

T3O

&

-PH

H

r1 o

CM

jj00

00

g\ CM

LO

CO

L-- H

rH

CO S) CO

a)

CO p

1

J" CO CO zt- • LO

CM

xj

rd

CU

CMH

o

P< rH

CO CD CM jg CM H g

#N CM LO CO H r»

r» H H rH o CM LO £ CM rH

C • O O • •H CO S o

CO P 3 s «

H rrj p -P H rH •H fn rd c • H rd

rd 3 Q -P CD O rd c C CD -P bO CO H CO S s C o bO bO

(1) •H =1 ft H •H H rd O ip, •P e 6 •H -p H -P CO CO C rd 6 e 3 fc & rd CO H O -P Q o o CO a1 o a) -P 6 CU

(D o 00 H o o o W PL, H CO CU -p

CO 2

w T3 >» >, C

CO CO W

SYSTEM MESSAGES DATA ELEMENTS (I)

Fig. 17

33
CO "—

H

(XH Pn (N oo

PhCO< : a*p<<\ H uo to 00 JCJ> H H rH H

M

: s

w

1 s

! M

1 J Q ! Q

H

I S

i H

i W

! S 00

! O O H oo co

Phs «% H r^ H

1—

^

S PQ

i w

en

CO CO Jd- | H H H

CO <

< * #> CQ no JO

a

-po

rd \

o . a O

rti CU 0) C

+-> -H e ,q

rd rti -H o H;

Q •a +-> •r~> H

bCC

•H s

-P O

CDO

O J

o .

r- en

1—

CO H H H

CM CO .H- UO CO 00 oo rCM CM CM CM CM CM CM CM —

CO —

CM H J- CM

CM CM CM EDCO

i H r1 H|

CM OO P CD

rH r o

Pia H

1 CM CD H 00 o

: CM cH CM CM CM

CD TJ +-> bi CU -P cu o Mh C 6 CO 3 CO CU Mh •H •H -P

• (^ P- fl! o -P -P 'H o £ rd C

! bl) •H a

c H Ol O TJ PL, ED

• o d) o H CU PL,

• o +-> CU o fl 3

# bO c O rd

in o £ Q) cu !h rQ 0) -P e q o

o CO a Eh rd •H pd P

T' 3 rd H T3 -P COj CO

PhPho

CDO

J

SYSTEM MESSAGES DATA ELEMENTS (II)

Fig. 18

34
7. REFERENCES

(1) "Standards for User Procedures and Data Formats in

Automated Information Systems and Networks." Little,

J. L. , and Mooers , C. N. , National Bureau of Standards,

Proceedings of the Spring Joint Computer Conference , 1968, pp. 89-94, 4 references.

(2) "Functional Specifications for Typewriter- Like TimeSharing Terminals." Dolotta, T. A., Princeton

University, Princeton, New Jersey. Computing Surveys , Vol. 2, No. 1, March 1970, pp. 5-31, 25 references.

(3) USA Standard Code for Information Interchange,

X-3. 4-1968. United States of America Standards

Institute. (Federal Information Processing Standard

Publication 1, November 19 68).

(4) American National Standard Vocabulary for Information

Processing. X-3. 12-1970. (FIPS PUB 11, December

19 70).

(5) American National Dictionary for Information Processinj

American National Standards Institute, in preparation.

(6) American Standard

Typewriter Keyboards

ASA X4. 7-1966.

(7) American National Standard

Alphanumeric Keyboard Arrangements Accomodating

the Character Sets of ASCII and ASCOCR.

American National Standard X-4. 14-19 71.

(8) Calendar Date

FIPS PUB 4

November 1968

U.S. Department of Commerce

National Bureau of Standards

(9) States and Outlying Areas of the United States

FIPS PUB 5-1

November 1968

U.S. Department of Commerce

National Bureau of Standards

(10) Counties and County Equivalents of the States of the

United States

FIPS PUB 6-1

June 19 70

U. S. Department of Commerce

National Bureau of Standards

35

<< U. S. GOVERNMENT PRINTING OFFICE : 1973—542-650/61

FORM NBS-H4A (1-71) U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO. NBS TN-799

2. Gov't Accession No.

3. Recipient's Accession No.

4. TITLE AND SUBTITLE

USER PROCEDURES STANDARDIZATION FOR NETWORK ACCESS

5. Publication Date October 1973

6. Performing Organization Code

7. AUTHOR(S)

A. J. Neumann

8. Performing Organization

10. Project/Task/Work Unit No. 640-2415

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

11. Contract/Grant No.

12. Sponsoring Organization Name and Address National Science Foundation

1800 G Street, NW

Washington, D. C. 20550

13. Type of Report & Period CoveredInterim

14. Sponsoring Agency Code

15. SUPPLEMENTARY NOTES

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

bibliography or literature survey, mention it here.)

User access procedures to information systems have become of crucial importance

with the advent of computer networks, which have opened new types of resources to

a broad spectrum of users. This report surveys user access protocols of six representative systems. Functional access requirements are outlined, and implementation

of access procedures is analyzed by means of a common methodology.

Qualitative assessment of standardization possibilities identify standardization

candidates such as: system and user signals, on-line user entries, system requests,

and network wide categories of message content.

17. KEY WORDS (Alphabetical order, separated by semicolons)

Network access procedures; networking; standardization; user protocols.

18. AVAILABILITY STATEMENT

[Xj UNLIMITED.

I I FOR OFFICIAL DISTRIBUTION. DO NOT RELEASE

TO NTIS.

19. SECURITY CLASS

(THIS REPORT)

UNCLASSIFIED

20. SECURITY CLASS

(THIS PAGE)

UNCLASSIFIED

21. NO. OF PAGES

43

22. Price

70^

USCOMM-DC 66244-P71