NASA Technical Memorandum 109924

NASA Access Mechanism_ Lessons Learned Document

Judy Hunter Denise Duncan Curtis Generous Lisa Burdick Rick Dunbar John Lycas Ardeth Taber-Dudas National Aeronautics and Space Administration Washington, DC

July 1994

STI PROGRAM SCIENTIFIC & TECHNICAL INFORMATION This publication was prepared by the NASA Center for AeroSpace Information, 800 Elkridge Landing Road, Linthicum Heights, MD 21090-2934, (301) 621-0390. Table of Contents

CHAPTER ONE - Background I.A. WHY A GATEWAY PROTOTYPE? ...... 1 I.B. PROJECT HISTORY ...... 1 I.B. 1. NASA STI Program Overview ...... 1 I.B.2. User Requirements ...... 2 I.B.3. Conceptual Design ...... 4

CHAPTER TWO - Prototype II.A. SYSTEM DESIGN CONSIDERATIONS ...... 7 II.A. 1. Hardware Factors ...... 7 II.A.2. Operating System Factors ...... 8 II.A.3. Graphical Interface Factors ...... 8 II.A.4. Development Tools Factors ...... 9 II.A.5. XWindow Development Toolkit Considerations ...... 10 II.A.6. Networking Considerations ...... 10 II.A.7. Z39.50 and POSIX ...... 12 II.B. ALPHA DESIGN AND IMPLEMENTATION ...... 12 II.B. 1. Time Constraints ...... 12 U.B.2. Technical Design ...... 12 II.B.3. NAM Modules ...... 14 II.C. BETA IMPLEMENTATION ...... 16 II.C. 1. System Redesign ...... 16 II.C.2. Hardware/Software/Network Requirements ...... 18 II.C.3. Beta Test Participants ...... 19 II.C.4. Schedule ...... 19 II.C.5. What Did We Provide? ...... 20 II.C.6. Statistics on Responses ...... 20

CHAPTER THREE - Lessons Learned III.A. DEVELOPERS' FINDINGS ...... 21 III.A. 1. Findings During Development and Testing ...... 21 III.A.2. Findings From Log Files and Monitoring ...... 22 III.B. USERS' FINDINGS ...... 22 III.C. PUBLIC DEMONSTRATIONS AND TRADE PRESS ...... REACTIONS ...... 24

CHAPTER FOUR - Options IV.A. CREATE NAM-Lite ...... 26 IV.B. USE WORLD WIDE WEB FORMS ...... 27 IV.C. CREAT NATIVE CLIENTS WITH SMALL REWRITE ...... 27 IV.D. CREATE FRONT END FOR INTERNET TOOLS ...... 27 IV.E. NAM - THE NEXT GENERATION ...... 27 IV. F. THROWAWAY NAM ...... 27 IV.G. OTHER CONSIDERATIONS ...... 28

CHAPTER FIVE - Recommendations V.A. SHORT TERM ...... 29 V.B. LONG TERM ...... 29 V.C. MANAGEMENT RECOMMENDATIONS ...... 29

GLOSSARY ...... 30

I.B. PROJECT HISTORY CHAPTER ONE- Background I.B.1. NASA STI Program Overview

The NASA Scientific and Technical I.A. WHY A GATEWAY Information (STI) Program was PROTOTYPE? established as a result of the National Aeronautics and Space Act of 1958 to The National Aeronautics and Space identify world-wide sources of scientific, Administration (NASA) Access technical, engineering, and related Mechanism (NAM) was initiated to information; develop required policy demonstrate the feasibility of using a statements; facilitate authorized access; (GUI) and and manage delivery of the information to intelligent gateway technology to NASA and its customer base. STI is basic streamline access to sources of Scientific and applied research results from the and Technical Information (STI). efforts of scientists and engineers. It includes new theory and information The NAM project is based upon a obtained from experimentation, technology known as the Intelligent observations, instrumentation, or Gateway Processor (IGP). The IGP computation in the form of text, numeric concept was pioneered by Lawrence data, or images. STI may be further Livermore National Laboratories (LLNL) transformed, described, evaluated, and/or in 1983 in a joint effort sponsored by synthesized and recorded in print, digital, NASA, the Department of Energy (DOE), magnetic, or other media to enhance its and the Department of Defense (DOD). communications and its usefulness and They adopted a national bureau of value to a wide spectrum of users and standards project known then as the USES. Network Access Machine. From a historical perspective, NASA was The purpose of the NAM prototype was to a leader in acquiring and processing STI in demonstrate to the NASA user community the mid 1960s to the late 1970s. The user the concept of a system of this type is to requirements and the services and products streamline access to diverse sources of provided by the Program were in harmony. information in the NASA environment. To The REmote CONsole (RECON) retrieval measure the applicability of the system, it engine was the first of its kind to provide was necessary to obtain feedback from users access to NASA's bibliographic selected users in various occupations. This database system. In fact, RECON was a was accomplished by fielding the system model for commercial companies and at user sites for a six-month testing period. other Federal agencies. From the late 1970s to 1990, the NASA user The members of the NAM Development requirements became unknown and Team had experience with intelligent NASA's operation remained unchanged gateway and GUI technologies. The team while other Federal organizations moved brought the lessons learned from their ahead. In 1990, NASA was still using the previous experiences to NASA. The first system that was developed in the 1960s step was to evaluate the strengths and with few changes. Beginning in 1990, new weaknesses of the previous management began to implement Total implementations and to make decisions Quality Management (TQM) about what would and would not meet the methodologies to improve the current NASA requirements. operations while planning to modernize the fragile Program. One of the projects initiated during this period was the NAM effort. A strategicvisiondocumentpreparedby information. The NASA user community theProgramstated,"thefocusof oureffort consists of NASA researchers, engineers, will be thedevelopmentof aglobal librarians, managers, and the broader programto encouragethecreationand university and aerospace industry exchangeof STI andfacilitateits use."To communities. implementthiseffort theProgramneeded to knowthefollowing: The primary objective of the study was to assess the potential for an intelligent • Theinformationrequirementsfor the gateway to meet NASA users' R&D community requirements for online STI retrieval. The study was limited to a sample of the user • Therelevantinformationsourcesto community and included NASA's Ames meetthoserequirements Research Center (ARC), Langley Research Center (LaRC), Lewis Research Center • Waysof facilitatingaccessto those (LeRC), and Goddard Space Flight Center informationsources (GSFC).

A teamcomprisedof multiplecontractors After the results of the study were wasformed.CurtisGenerousof UUcomis gathered and examined, the NAM project theSeniorTechnicalManagerresponsible scope changed; the prototype's design was for thetechnicaldesignandoverall expanded to include internal databases to managementof theproject.Rick Dunbar NASA such as RECON, as well as of UUcomis theSeniorAnalyst external databases such as STN and WAIS responsiblefor programmingandporting sources. In addition, the prototype design thecodeto otherplatforms.Denise was changed to include peer locating tools. Duncanfrom LogisticsManagementInc. This feature was added in response to the (LMI) is theInformationSpecialist users' expressed need, identified during responsiblefor performinguserstudies, study interviews. identifying sourcesof information,and interfacingandcoordinatingwith users. The Program knew that users needed a Duc Tran,undercontractto UUcom,isan simple way to locate and access STI from expertin theuseof X.11OSF/Motifandis their offices. They learned that users were responsiblefor theinitial designand using a variety of methods to do this: programmingtheGUI. JohnLycas(LMI) chatting with coworkers in their group, is theInformationSpecialistresponsible calling or writing colleagues for referrals for initial designandresearchingX to other experts or for information, going serverson PCs.ArdethTaber-Dudasand to the library or calling the librarians, and, Lisa Burdick (bothof RMSAssociates) infrequently, directly accessing areresponsiblefor creatingtheonlinehelp information sources from their desktops. screensandtheNAM UserManualand Their information and support providingoverall support. requirements are described in the NASA Gateway Requirements Analysis (NASA JudyHunter,astheManagerof Special TM-104951) published in March, 1991. Projectsfor NASA, is responsiblefor the This document summarizes the overallgovernmentmanagementof the alternatives and recommended actions, project. conclusions, and findings resulting from the study. I.B.2. User Requirements There was a high degree of consistency in In 1990, the NASA STI Program the user responses regarding the functional conducted a study to evaluate the requirements of an improved STI delivery feasibility of using the IGP and GUI system. The requirements of the majority technology to meet the NASA users' of interviewees can be grouped in three requirements for access to online parts: 1.Broader And Deeper Coverage Of of six months to allow users to Relevant Disciplines. Users expressed a evaluate the utility of access to need for comprehensive coverage of the new STI sources. disciplines in which NASA performs basic and applied research. This includes . That the prototype designers improved subject coverage of engineering, select a limited set of STI physics, geology, mathematics, electronics sources representing the variety and control systems, materials, U.S. and of available on-line STI and international patents, and life sciences. having the highest relevancy to the prototype user community. 2. Improved Identification of These were to include a source Information Sources. Users indicated that of information on research they need assistance identifying and performed outside the U.S.; retrieving pertinent STI from all major sources of chemistry, materials, foreign sources, and accessing numerical physics, engineering and patent data sets that result from previous information; resources; and observation-based research. At a access to human resources, minimum, they need assistance in locating such as the larger research STI sources within NASA, the U.S., and community and the STI internationally, even where gateway Program staff. access is not feasible.

. That the prototype include the 3. Improved Access to Information applications most frequently Sources. Users specified the need for requested by users, and that it reliable telecommunications off-Center; have a two-level interface: one for example, simplified electronic mail level for end-users and one for across varying mail systems and networks library staff. and increased information about, and access to, resources. They also need access . That the prototype be based in to some Center library services from their Center libraries and selected offices. They need to execute simple STI end-user offices. queries from their desktop systems. These queries include querying by parameters . That the prototype use existing other than text--for example, by chemical networks to provide simplified, structure--and retrieving complete reliable telecommunications documents with graphics intact, browsing paths connecting user STI sources and querying results, and workstations, the prototype forwarding retrieved foreign materials to a host, and the remote translation service. They should be able to information sources. set up queries for automatic execution on a dally, weekly, or as needed basis to keep . That all organizations that aware of specific topics. participate in STI delivery and use be included in the The requirements report recommended six prototype. actions: A listing of user requirements is shown in . That the STI Program provide a Table 1, with comments on how the prototype intelligent gateway prototype addressed these requirements. for user testing for a minimum User Tech Met Comments

Comprehensive discipline ,¢ B Alpha-D file, STN-Math, Inspec coverage Beta-All except D, STN-ChemAbs, Medline .... Improved source information 4 q A Database in Source Locator Improved access to sources 4 A/B Usable access to/reliable telecommunications vm Improved telecommunications Libraries have substandard equipment and off-Center resources Simplified email q A/B Pop up mail/peer iocator/user agents Full text 4 Full text data sources too expensive (requirement technically met / Multimedia 4 Not technically feasible Queries based on non-text ./ ,/ Time constraints _narameters creased information and access ,¢ 4 A/B Usenet, ARCHIE, Gopher, Mosaic ABA/BBB Simple desktop queries 4 A/B Desktop library access ,¢ B Ordering documents, email Current awareness system q Time constraints Electronic browsing of sources 4 A/B and results Textual translation No available on-line translation service Multi platform support q Time constraints Wide area connectivity PSCNI _/ Am hosts Graphical User Interface "_ Am Multilevel interfaces 4 Am DecNet connectivity (SPAN) q PSCNI _/ A NSI ,,t a

Standards based approach ,¢ Am Simultaneous Search DBs 4 Time constraints Peer Locator q Am Canned queries/batch ,¢ Time constraints Customizable forms q Time constraints

Table 1. Summary of Prototype Responses to Requirements * A indicates Alpha prototype version and B indicates Beta prototype version

Design of the NAM, which began in the fall of 1991, was based on users' I.B.3. Conceptual Design requirements stated in the NASA Gateway Requirements Analysis document. Other In the summer of 1992, the STI Program factors that could have an impact on the assembled a team to respond to the ability to use rapid prototyping recommendations stated in the methodologies were also employed. The requirements report. The team operated initial plan was to have a working under two major constraints: a working prototype for testing within a year. prototype was needed within one year, and the budget for hardware, software, and A working version of the prototype was personnel was limited. first demonstrated in April 1992 at the NASA STI Managers' Conference. The concept for the NAM was a unique the prototype evaluation. The user approach to STI assistance: a desktop tool interface was limited to terminal to assist scientists, engineers, and emulation, and in general, the software information specialists in locating and was not modular enough. using a complex mix of resources. These resources included formal and informal Defense Gateway Information System sources of information for many (DGIS) from the Defense Technical disciplines, Internet resources, and Information Center (DTIC) channels of communication with fellow DTIC was one of the sponsors of the scientists and engineers and information original IGP development at LLNL. DTIC professionals. In essence, this system continued development of the software in represented an expansion of the definition the DGIS in the 1980s. It had many of the of STI to include Intemet resources and same limitations as the IGP software-a human beings. centralized architecture, with users connecting to the host minicomputer via a In addition to this wider variety of VT 100 terminal emulation; no Application resources, the NAM concept included a Programming Interface (API); and thus no higher degree of integration than was potential for a GUI. In general, the heretofore seen in STI systems. This software would not port well to a desktop tool had to support (as much as distributed computing environment. feasible) all the ways users find, get, and use ST/, so they would only have to install Foreign Market Analysis System and use one STI tool. It had to be (FMAS) prototype developed by the integrated into the user's desktop Army Materiel Command (AMC) environment, so it would be natural to FMAS was developed based on the DGIS incorporate its use into the normal work software and had all the limitations of the patterns. It had to be easy to use (less than DGIS software. However, in the VT 100 a half-day of training) for the beginner, screens, a query form had been used. This and not constraining to the experienced type of query preparation screen had been user. For both integration into the desktop used successfully by engineers at the U.S. environment (which was primarily that of Army Laboratories. a workstation, Macintosh, or personal computer) and ease of use, a The commercial software packages graphical user interface was desirable. reviewed included Ascent Gateway, STILAS, and Grateful Med. With this concept in mind, the team evaluated software available from other Control Data Corporation's Ascent agencies and commercial off-the-shelf Gateway software is a commercial version (COTS) software in terms of its potential of the DGIS system. It includes database for the NAM prototype implementation. access and query capability, electronic Some of these systems are listed below, mail, and internal peer location with a summary of the reasons each was mechanisms. It lacks a GUI and a not used in the NAM: distributed architecture.

Intelligent Gateway Processor (IGP) SIRSI Corporation's STILAS software Software from Lawrence Livermore offered multi-database searches, but no National Laboratories (LLNL) tools for access to 'informal' data sources, The original IGP technology was such as peers and bulletin boards. It would developed by LLNL under contract to have required a great deal of modification NASA, DOD, and DOE. The NAM team to provide Internet tools and a GUI. Since obtained a copy of this software from all modifications to the software had to be LLNL and found it too inflexible, both for performed by SIRSI corporation, it was the initial modifications to create the NAM not flexible enough for prototype prototype and those needed in response to development. GratefulMed is theNationalLibraryof community'srequirements.Theprototype Medicine's(NLM) frontendto their developmentwasdesigned,implemented, Medlinedatabase.It consistsof asoftware andcodedwith theunderstandingthat this packagethatallowsasynchronous wasathrowawaysystemthatwasto be communicationsbetweenaMacintosh usedsolelyasa rapidprototypefor the computerandthehostdatabasemachine. purposeof demonstratingtheconceptto Thispackagewasinflexibleandunableto theNASA usercommunity.During the supportothercommunicationscapabilities Betatestphase,constantmonitoringof the (i.e., TCP/IP),wassupportedonly on the usageof theprototypeandongoing Macintosh,anddid notsupportother communicationwith testersallowedfor databases. thedesignto berefined.Thisresultedin a totalof threeprototypeversionsbeing After reviewingthefeasibilityof using released,eachwith featuresandfixes existingintelligentgatewaysoftware, requestedby thetestcommunity. NASA decidedto developaprototype basedon thenewerLLNL sourcecode. A numberof designconsiderationsand After a studyof theprogram,it was practicalconstraintsdeterminedthe determinedthattoomanychangesand developmentenvironmentandthescopeof modificationswererequiredto importthe theprototype. functionsneededto meettheNASA STI were considered. These included CHAPTER TWO- TCP/IP, OSI, DECNET, and AppleTalk. The platform had to Prototype support all of the above protocols, either as a standard part of the operating system or through add-on II'A. SYSTEM DESIGN hardware/software. CONSIDERATIONS That it support the GUI interfaces II.A.1. Hardware Factors proposed to be used by NAM. This meant that color bitmap screens had to The hardware requirements for the NAM be supported by the hardware. prototype were as follows: That the development team have some That it be well-suited for development. knowledge of the hardware • The design team wanted assurance that environment. This requirement was hardware factors would not impair the key to implementing the prototype software development process. This within a year. meant finding an industry standard hardware platform for which tools and That it serve as a multi-purpose software could easily be obtained from computing platform. The machine also third party vendors. had to provide local services such as email and basic wide area network That it support the networking and services such as routing and domain communications capabilities needed name support to the local area network for NAM. At the time of the original shown in Figure 1. design, many networking protocols

Novell SMTP Server Mail Mats PCs Gateway Printers NSI Router

Thin Ethernet

nova.sti.nasa.gov Sun 4/470 Server Spares

Figure 1. STI Program LAN II.A.2. Operating SystemFactors NAM development team had several options available to them at this time: Additionally, the prototype specification Sunview/XView contained requirements that needed to be supported by the operating system: Sunview was immediately rejected due to it's proprietary nature and the fact Multi-tasking. The NAM prototype that the vendor () server would be supporting many had announced plans to drop support in the near future. simultaneous users concurrently.

Mac OS OS support of networking facilities. The networking capabilities of the The prototype developers had the hardware needed to be supported as option of developing a GUI for the an integral part of the system. The Macintosh Operating System (MacOS); however, the intended design team's experience with the socket level abstraction provided by audience for the prototype included other than Macintosh users and this many OSs strengthened this requirement. option was restrictive. Microsoft Windows Process control capabilities. The distributed client/server design MS Windows was by far the most approach required that the OS include popular platform among the intended users. The lack of standardization in background processing, process control, and violation protection. development tools and communications API's caused User access control. Because the concerns on the support of such a NAM server supports simultaneous platform. users, the OS facilities should support the concept of user identification and The choice of MIT/X 11 Revision 4 provide facilities for authentication , was made for several reasons: and authorization. This would give the NAM server the capability of accessing and granting permissions to It was standards based, as the X individual users, and groups of users, protocol was an accepted standard and source or target host in FIPS PUB 158-1 (IEEE identification. P1295.1)

Must comply with FIPS requirements It was a widely used environment to meet all POSIX specifications, in the NASA scientific and including P1003.1. engineering community.

After reviewing all of these above It was freely available in the public domain with full source code and was a requirements, the UNIX-based operating de-facto standard on most workstations system (or a variant of) was chosen as the operating system of choice. such as SUN and Silicon Graphic.

DOS, Microsoft Windows, and MacOS II.A.3. Graphical Interface Factors users could be supported by purchasing a commercial X server for their It was also necessary to decide what workstations. All users would be able to windowing environments the graphical use the GUI from their own desktop user interface (GUI) would support. The computer. II.A.4. Development Tools Factors was made available for creating the prototype. A compiler for the C To facilitate the development effort, it was programming language is provided with agreed that the following guidelines the operating system and is the language should be considered in the selection of an of choice of the developers. Many public acceptable environment: domain utilities and tools were also used during the development phase of this Support industry standard high level project, including such facilities as the language compilers, such as Pascal, or following: ANSI-C. Perl: an interpreted language optimized Support standardized Application for scanning arbitrary text files, extracting Programming Interfaces (API) information from those text files, and whenever possible to support all of the printing reports based on that information. low level routines. It's also a good language for many system management tasks. The language is Install tools and facilities to support intended to be practical (easy to use, development in a multi-platform, efficient, complete) rather than beautiful distributed environment. Since the (tiny, elegant, minimal). It combines some development would be done by several of the best features of C, sed, awk, and sh, people working on different sections of so people familiar with those languages the application at one time, the ability should have little difficulty with it. to support such a work group was (Language historians will also note some necessary. vestiges of csh, Pascal, and even BASIC- PLUS.) Expression syntax corresponds Have available proper debugging tools quite closely to C expression syntax. and utilities to support a multiple Unlike most UNIX utilities, Perl does not developer environment; such tools arbitrarily limit the size of your data-if include revision control utilities, you've got the memory, Perl can slurp in linker, preprocessors and incremental your whole file as a single string. loaders. Recursion is of unlimited depth. And the hash tables used by associative arrays Support the Graphical User Interface grow as necessary to prevent degraded (GUI) environment that would be performance. Perl uses sophisticated selected (see Chapter II.A.4 above). pattern matching techniques to scan large amounts of data very quickly. Although After careful review of all the available optimized for scanning text, Perl can also options, and in view of all of the factors deal with binary data and can make dbm and considerations outlined above, the files look like associative arrays (where selection of a SUN SPARC was made. The dbm is available). final architecture of the prototype test bed consisted of a SUN 4/470 SPARC server, Xups: a graphical source level debugger chosen as the hardware platform for for the C programming language running under the X 11 and SunView window development because it has a robust Operating System (SunOS) and a contract systems. It supports both run time was already in place that would allow the debugging with breakpoints and post- mortem debugging from a core file. On procurement period to be relatively short. Two SUN SPARC IPC workstations were Suns you can attach ups to a running also purchased to be used for process. Xups runs in its own window, development. thus not interfering with the target program's I/O. The Xups window has two major areas - one showing a structured Since a UNiX-based development environment was chosen, a rich set of tools document representing the target state, the othershowingthesourcethatisbeing staff also had previous experience in executed. developing applications with OSF/.

Zmail: zmailis aMIME-compliantmail II.A.6. Networking Considerations useragent(MUA) thatcansupportoneof severalmail transportagents(MTAs).In The STI user community is geographically its typicalconfiguration,zmailsupports dispersed and therefore presented some SMTP.Zmail supportstwointerfaces:an constraints on the communications X/Motif graphicaluserinterface,anda alternatives that were available. The NAM commandline interface. development team had several wide area network alternatives to choose from: H.A.5. XWindow Development Toolkit Considerations NASA Wide Area Connectivity NASA's current wide area connectivity Once the selection of an appropriate includes TCP/IP and DECNET wide area windowing system was made, the selection networks provided by the NASA Science of an appropriate toolkit to support the Internet (NSI) and the Program Support "look and feel" that was desired for the Computer Networks Internet (PSCNI). prototype was needed. The options Both the NSI and PSCNI provide available to the team at the time consisted connectivity between NASA Centers. The of : PSCNI does not, in general, provide connectivity to the Internet. The NSI is a Xiib more open network that is designed to was eliminated immediately due to facilitate communications with NASA the very complex nature of this low-level researchers globally, and as a result library, and due to the enormous amount provide good Internet connectivity for of work necessary to develop original NASA researches. Our goal was to support widgets to standardize the look of various the entire NASA research community so forms. we chose the NSI as our wide area network provider. Andrew Toolkit The Andrew Toolkit was eliminated next GOSIP because of poor developer support and In addition, there was the need to support limited functionality. The Andrew toolkit GOSIP (Government OSI Profile) which is a public domain toolkit that was one of mandates the use of Open Systems the first developed for X 11 programmers. Interconnection (OSI) networking protocols where feasible. There is OpenLook (OLIT) Toolkit vs. currently very little OSI support and few OSF/Motif OSI products available. The Open Look toolkit versus OSF/Motif were then the only two choices left. After Due to the lack of wide area OSI support conducting an informal market survey of and products, we chose to use the TCP/IP software firms and agencies doing their networking protocol suite due to it's own X 11 developments, we found an extensive availability and reliability. approximate 3:1 ratio of Motif-based Furthermore, since TCP/IP was on the applications over OL1T. The development NASA Inter Center Council on team chose the OSF/Motif toolkit because Networking's (ICCN) list of Approved it was more widely implemented and this Short Term Protocols, this would not increased the probability of incorporating violate the ICCN mandate during the the NAM gateway with other X 11 systems migrating to OSI. (ICCN is the NASA in the future. OSF/Motif is also based on Council responsible for implementing OSI Xlib which would provide a simpler in the NASA community). The development environment and a more development staff also had extensive pleasing look and feel. The development

10 backgroundin thedevelopmentof TCP/IP conferences and at other government basedservices,andwereespecially agencies. familiar with thesocketlevelabstraction thatis providedby mostUNIXbased X Protocol over Serial Line platforms.Socketsareanendpointfor For those platforms (e.g. Sun's, Hp's) communicationbetweenprocesses,similar which use the X-Windowing system as the to theway atelephoneistheendpointof GUI, the use of a specialized X transport communicationbetweenhumans.Each protocol over serial lines is also an sockethasqueuesfor sendingand alternative. There are three known receivingdata.Socketsaretyped implementations of this capability, two accordingto their communications proprietary and one an in-process standard. properties.Thesepropertiesinclude whethermessagessentandreceivedata X-Remote - NEC's proprietary socketrequirethenameof thepartner, implementation of a stripped down X whethercommunicationis reliable,the protocol which essentially allows X to formatusedin namingmessagerecipients, run over a non-IP stack. By etc. eliminating the TCP/IP protocol overhead and through the use of Communications compressing and tokenizing To support a truly distributed application, techniques, NEC has been able to it is imperative that packet level obtain fairly good benchmarks. Field connectivity exists between each module tests of this technique showed in the NAM application group. The lack of acceptable levels of performance when such packet level connectivity can be used in conjunction with V.32bis resolved through the use of several modems (14.4 Kbaud modems). The alternative connectivity tools including: display of large graphic images, such as those used in the weather maps on Asynchronous Communications the NAM system, proved to be too There was also a need to support slow for acceptable use. Although a asynchronous communications such as dial proprietary protocol, NEC has released up access for users who did not have the details of the protocol to the X Internet connectivity. This option Consortium which is in the process of presented bandwidth limitations. There are making the X-remote a baseline a number of ways to support both IP and release for the Low Bandwidth X the over asynchronous (LBX) protocol in the future release of dial-up lines including Serial Line IP the X 11 Release 6 Windowing system (SLIP), which is a widely implemented but (see LBX below). non-standardized protocol, and the Point- to-Point Protocol (PPP). PPP has been X-Express - Another competing described and accepted as a standard and technology attempting to duplicate offers many built-in features which make NEC's proprietary implementation. the configuration and management of a This protocol was not tested during the PPP connection much easier. Performance Beta test phase since as it became of a PPP connection is also supposedly commercially available only during the higher due to various techniques built-in to last few days of the testing period. This the protocol such as Header compression, approach is also a proprietary Type of Service (TOS) prioritizing, technique: there are no plans on automatic IP addressing negotiation, and making the protocol publicly available. others. Low Bandwidth X (LBX) - NEC's In general, we decided not to support dial- proprietary implementation of a up access for our test community. We did, stripped down X protocol has been however, use asynchronous released to the X Consortium who is in communications for demonstrations at the process of making a slightly

11 modified version of X-remote as the 1992. In February of 1992 the release date Low Bandwidth X (LBX) protocol in was changed from June to April so that a the future release of the X 11 Release 6 presentation and demo could be made at Windowing system. Once this process the annual STI Managers Conference to be is done (late 1993/early 1994), the held in Houston at the Johnson Space definition of LBX will be finalized and Center. This change in plans finalized published as a standard. No hard data what would be in the prototype. The demo about performance and platform also brought forth the need for a SLIP support is yet available to the authors. connection for asynchronous communications. II.A.7. Z39.50 and POSIX Due to time constraints, many originally At the time of the prototype design, the planned capabilities of the alpha system specification for the 1992 version of the had to be cut, including the following: ANSI Z39.50 protocol had not yet been finalized. Furthermore, the handling of • Simultaneous searches of various non-Z39.50 compliant queries needed to remote databases be achieved to handle some of the unusual • Canned queries and batch processing characteristics of some of the remote data which would allow users to set up a sources being used, and these types of "current awareness" system for queries did not fit well into the Z39.50- themselves 1988 spec. As a result, Z39.50 was not • The number of remote systems which used in the prototype. would be queried • Accounting features to track cost and POSIX 1003.1 is the IEEE Portable usage information Operating System Interface for Computer • Non textual queries Environments. Its goal is to provide a comprehensive operating system II.B.2. Technical Design environment that application programmers can be confident will be supported across a The alpha prototype builds on the previous variety of machines. The IEEE 1003.1- work of many other people; many of its 1990 national standard was adopted in facilities are based on ideas and functions April 1933 as FIPS PUB 151-2 POSIX.1. from other projects and are presented in an POSIX-1 provides a low-level kernel intuitive, easy-to-use system. For example, operations API to support such tasks as query-by-forms interfaces have been used process control, signals, file management, in both structured and unstructured etc. At the time of the start of development databases. In addition, the Interact tools of the NAM prototype, neither the C provided under the Bulletin Boards and compiler nor the interface builder and Utilities icons were developed by others in Motif toolkit supported the POSIX. 1 and the Internet community. ANSI-C standards needed to perform POSIX. 1 compliant development. For this The distributed nature of the NAM reason, it was decided to not use the prototype was implemented using peer to POSIX. 1 API. peer inter-process communications techniques. There are several reasons for II.B. ALPHA DESIGN AND this modular design: IMPLEMENTATION By distributing portions of the application to different processors, a II.B.1. Time Constraints certain amount of replication can be provided to improve reliability of Development was started on the Alpha service. System in December of 1991. The scheduled release of the alpha was June

12 Improvedperformanceby distributing requirements of the prototype (limited portionsof theapplicationto avoid capability, cost, availability to use slow network links or bottlenecks that OSF/Motif, etc..). may exist. A diagram of the NAM architecture design Improved performance by dedicating is depicted in Figure 2. Each module of the machines to be associated with specific NAM is self-contained, capable of tasks, such as database machines, communicating with the other modules via where system load problems might a strict transaction protocol, using TCP/IP exist. as the underlying transport mechanism to assure a reliable, bi-directional Customization for a group or an communications path. The various individual is possible since the network capable interfaces among functionality of each module is clearly modules are shown in dotted lines, while defined and limited in scope. By using other interfaces which are internal paths, the Application Programming are shown in solid lines. The Interfaces (API), a site can easily communication path among components is customize the NAM interface to provided using TCP/IP-based inter-process provide specific capabilities needed for communications. This allows all the their users. modules to be running on the same machine or distributed among machines • Supports geographically dispersed connected via local and wide area users and data collections. networks. Connectivity between the NASA Centers was provided by the The NAM prototype had several false NASA Science Internet (NSI), which, in starts as the programming staff turn, is connected to the rest of the investigated the use of GUI development Internet. The NAM prototype was tools such as NASA's TAE+, Integrated designed to make use of this connectivity Computer Solution's Xcessory-Builder, to operate. and X-Designer. None of those tools fit the

Figure 2. NAM Modules

13 Support to a limited number of users of software (The X Window System) for the dial-up communications has been provided client ensures that the application will be using personal computers with Microsoft portable to the variety of platforms found Windows, XVision and XRemote in the user community. Use of the software, and high-speed modems for use OSF/Motif Toolkit provides a unified look at exhibits and demonstrations. and feel on all platforms (UNIX workstations, Microsoft Windows-based II.B.3. NAM Modules personal computers, and Macintosh systems). The NAM is composed of nine basic modules: The prototype was developed in a distributed, multi-vendor environment, • Graphical User Interface (GUI) with the use of standards emphasized to • Intelligent Source Locator maximize the potential for migration to • Database of Databases other platforms in future versions. The • NAM Server GUI was implemented as a single X 11 • Communications Toolkit client called xnam. • Communications Agents • Data Filters Xnam displays the top level icons to the • Utilities and Bulletin boards user and responds to his requests. This • Peer Locator Tools program uses fork() and exec0 to invoke any of the programs found under the The modules listed above are grouped into email, Bulletin Boards, and Utilities icons. several programs that were developed on a All of these programs are stand-alone Sun SPARC running SunOS 4.1.x. The applications that have been integrated into Graphical User Interface (GUI) consists of NAM for ease of use. two X-window clients that are executed and interact with the user. They are xnam To use the NAM, one's desktop computer and xconnect. The second program, ingd, is the information server for the Database must be able to display an X-window. DOS-Based and Macintosh computers of Databases and for the digital must have an X- phonebook. The last program, namd, is the installed for this to happen. The NAM NAM server which provides the developers did an informal study of connectivity to and talks to the remote databases on behalf of the user. These existing Xserver software based on reliability, speed, and ease of installation programs communicate with each other and maintenance and chose several for use over a network. with the NAM GUI. The software products chosen are listed in Table 2 The NAM Server, Communications below. Toolkit, Communications Agents, and Data Filters are written in Perl. The rest of the modules are written in the C programming language (K&R). The GUI IBM PC DOS with VisionWare, R5 is based on X 11 Release 4 using the Clones MS- eXceed Windows OSF/Motif 1.1 toolkit and is currently Macintosh MacOS MacX, eXodus R4 being ported to X11 Release 5 and the Sun SPARC SunOS mwm,,ctwm, R4, R5 OSF/Motif 1.2.2 toolkit. We are currently 4.I.X olwm, porting the code to IBM RS6000 and IBM AIX mwm R4 Silicon Graphics platforms. RS6000 Silicon IRIX R4 The NAM GUI is a custom built Graphics windowing application, tailored to the Table 2. Xll Servers requirements of the STI Program user community. Use of standards compliant

14 The user's computer must be connected to by the user to allow him to review a a TCP/IP network which can access the particular search strategy. Internet or use an asynchronous prot_ __ol for X11 over serial lines such as XRemote The NAM Server or LBX. The NAM server is a concurrent process that spawns a copy of itself for connection The Intelligent Source Locator so that a large number of users may access The intelligent source locator was it at any given time. The server provides implemented under the Data Sources icon user authentication and authorization, and in the GUI. The locator was implemented also logs all activity. The NAM server to allow users to query on a subject incorporates the following: without knowing which formal source contained the information. The locator • Communications Toolkit provides the following services: • Communication Agents • Data Filters • Provide a list of databases • Provide a list of subjects Communications Toolkit • Locate appropriate sources on the The Communications Toolkit provides a known subjects. modular approach to providing communications capability to information retrieval systems external to the NAM. The Database Of Databases This facilitates modification of the user The Database of Databases is the database interface in response to user testing, while that contains the information about the not affecting the server code. Another formal data sources that NAM provides module provides batch and delayed access to. In addition, the data used by the operations. That spawns the appropriate NASA phone book under the Peer Locator agent and accepts commands from the Icon is maintained under the same remote user. database management system. The databases and their subject coverage is The Communications Agents manually maintained by the developers. The Communications Agents are PERL scripts spawned by the Communications The server's database contains the Toolkit that connect and communicate Database of Databases, the digital NASA with the remote database on behalf of the phone book, subject lists, connections user. data, and costing data. The Database of Databases maintains the records of remote The Data Filters sources, their subject coverage, and The Data Filters provide reformatting relevance scores for each subject. functions. They decode the data coming from the remote host and translate them to Xconnect is launched when a user requests a standard format to be used by the GUI. to connect to a database. This program Tags used for various headings are manages all of the query-by-forms screens, translated into English; time and date communicates with the NAM server, and stamps are put into a common format; and controls the display of output from the user prompts are eliminated. The data communications toolkit. The internal filters are built into the communications routines extract relevant information from agents. The filters are maintained by the the form, generate a valid query syntax for developers. the remote host, and then ships that query out. Currently, the query strings are built Utilities and Bulletin Boards on the server in Crystal City, VA and then sent to the remote database. A historical Everything that falls under the Bulletin Boards and Utilities main icons are tools track of all queries is kept and is viewable that are freely distributed on the Internet.

15 They are all X applications that work on a manipulation, and the presentation of the variety of hardware platforms and application stayed essentially the same. operating systems and have been Several of the changes were made as users integrated into the NAM for ease of use were beta testing the system and citing for the NASA STI user community. The problems to the developers. A list of the table below shows which utilities were major changes from the alpha version to available under these icons for the ALPHA the beta version are noted below. prototype. GUI The beta version gained increased Usenet News nn news reader performance by keeping all data structures ARCHIE xarchie version 1.3 in memory. The alpha version used a number of temporary files to store data Local Time xclock downloaded from remote databases. This Weather Forecast xforecast change was a major efficiency and speed Weather Maps fetchmaps and gain at the expense of larger memory xloadimage requirements.

Table 3. Alpha Version Utilities and In the alpha version the INGRES database Bulletin Boards calls were hard coded into the X 11 GUI. This dependency was removed. A new Peer Locator network server process was created (called This module consists of the following ingd). Now the GUI establishes a tools: connection to the database server when queries are made via the Source Locator or • finger NASA digital Phone Book. • NASA Phone Book • whois The GUI was split into two separate X 11 client programs. The xconnect program Query-by-form interfaces are provided to was responsible for establishing a all of these tools as well as a pop-up email connection to the NAM server (namd), function. This allows a user to click on the controlling the query by forms screens, email address of the person being searched and for translating the query to be sent to for and immediately send mail without the remote database. The xnam program typing the address of the recipient. was responsible for displaying the main icon box, providing job control for The UNIX finger and whois commands are invoked processes, and invoking xconnect when connections to the formal data available to dynamically query NASA and non-NASA machines. The NASA Phone sources were required. The following Book provided in NAM is a static major changes were also made: collection of digital telephone directories obtained from the NASA Centers during Under the data sources icon, additional the beginning of the prototype. These data sources were made available. MEDLINE and Chemical Abstracts are stored in a local Ingres database were made available through STN as H.C. BETA requested by some of the beta testers. IMPLEMENTATION • STN was no longer searchable by journals. II.C.1. System Redesign The file D collection within NASA The beta version of the software addressed RECON was disabled due to the fact many internal problems dealing with data that there are limited access records there which could not be made available to the general public.

16 Native mode connections were added to support expert searchers who did not wish to be restrained by the forms help Retuni list of valid commands interface. dblist Return list of databases Subiect list Return list of subwects • A number of the selection screens were locatedb "subject" Locate db based on simplified or removed. subiect locperson "first" Return phonebook data "middle" "last" "code" An optional status window was created "center to record billing costs for the various databases. Table 4. Defined Set of Requests

The long citation display was Email formatted for easier reading by using Electronic mail is provided in two basic bold facing and an easier to read flavors. There are email interfaces such as format. Elm and ZMail provided to allow users to send, receive, filter, and file their Intelligent Source Locator electronic mail. There is also a custom The intelligent resource locator module "pop up" mail interface available in the provides information about the various Data Sources and Peer Locators. This remote sources and their coverage of facility is used to email search results to subjects of interest to the users. It provides the user when searching the data sources. a mechanism to update a source's It's also used in the Peer Locator when a relevance score for the chosen subject, search yields a email address. based on the user's disposition of search results from that source. The locator was Utilities and Bulletin Boards changed to use a new program called ingd A number of useful tools became available to query the Database of Databases which on the Internet and were incorporated maintains the records of remote sources, under the Bulletin Board and Utilities their subject coverage, and relevance icons. They included ARCH/E, mosaic scores for each subject. and gopher. Weather maps and satellite images were also made available to Database Server demonstrate to users the capability to In the alpha version the INGRES database download graphics. calls were hard coded into the X 11 GUI. This dependency was removed in the beta Table 5 shows the publicly available version. A new network server process programs incorporated into the Beta was created (called ingd). Now the GUI Prototype. establishes a connection to the database server when queries are made via the Utility: A_U_ Pt_O_l'_n source locator or NASA digital Usenet News xrn version 6.17 ARCHIE xarchie version 1.3 phonebook. WAIS xwais fi'om li'ee WAIS- 0.1 The ingd is a concurrent server that World Wide Web xmosaic version 1.1 accepts a set of well defined requests, Gopher x_opher version 1.3 queries the database server, and returns the Local Time sunciock results. See Table 4. Weather Forecast xforecast Weather Maps fetchmaps and xloadimage

Table 5. Beta Version Utilities and Bulletin Boards

17 Peer Loeator Tools is connected to the Internet via the NASA Under the peer locator icon, the Knowbot Science Internet (NSI). Users received an and DNS queries were removed. The account on nova.sti.nasa.gov, connected Knowbot program did not work properly, via the Internet, and then executed the and the DNS query function was not application; the display of each session useful or understandable by most users. was transmitted back to the user's local The X.500 services were added because workstation and displayed using an X NASA, as an agency, had decided to Window manager. Thus there were two support X.500 Directory Service Agents basic requirements of beta testers: 1) their (DSA's) at each of the NASA Centers to PCs, Macs, or UNIX workstations had to simplify electronic mail addressing. The have TCP/IP connectivity to the Internet, Digital NASA phonebook that we had and 2) they had to be able to display an X originally collected was allowed to Window. See Figure 3. stagnate since an up-to-date X.500 system seemed provide current data. The first requirement, Internet connectivity, eliminated many of the II.C.2. Hardware/Software/Network NASA libraries from the beta test, since Requirements most did not have TCP/IP connectivity to the Internet. Other libraries were not For the prototype test, the NAM software allowed to participate because their local was maintained on a single server with the network administrators felt that X IP address nova.sti.nasa.gov, in Arlington, Window-based applications would cause Virginia; both the NAM client and the too much network traffic on their local server ran on that machine. This processor

Beta Test Connectivity Requirements _TCP/IP LAN

TCP/IP LAN a

I

LAN /IP LAN

Mac

Figure 3. NAM Prototype Connectivity Requirements

18 area network. This was not true, but they six-month period. A complete list of the could not be persuaded otherwise. participants and their organizations are listed in Appendix A. The second requirement, X-Window capabilities, did not eliminate many NASA H.C.4. Schedule employees or on-site contractors; the majority of these beta testers .already had Date the X Windows display capability. Where Nov-91 Technical Design necessary, the NASA STI Program was Dec-91 Start Development able to supply limited numbers of users with the X server software needed for PCs Apr-92 Alpha Demo @ STI Conf. Jun-92 and Macs, including eXodus, eXceed, or Original Alpha Due Date Disk Drives Delivered XVision for the PC, and MacX or eXodus Au_-92 for the Macintosh. For the UNIX Dec-92 Begin Beta Test With Six Users workstations, no software was purchased, since X Windows capability is generally Jan-93 Present NAM at AIAA included with that class of workstation. If Meeting not supported by the vendor for a Jan-93 Add 14 Testers particular UNIX workstation, the entire Feb-93 Add 10 Testers X 11 Release 5 is available at no cost on Apr-93 Add 1 Tester the Internet via anonymous ftp. May-93 Add 9 Testers, GCN Article Jun-93 End Official Beta Test II.C.3. Beta Test Participants Jul-93 Computerwodd Article Jul-93 > Over 250 Inquiries The requirements analysis report recommended testing the prototype with a Table 6. Project Schedule minimum of fifty users for a period of six months. After the initial demonstration of The requirements analysis report was NAM at the STI Managers' Meeting in delivered in March 1991. Market analysis Houston in April 1992, we solicited began immediately to determine if there participation from the NASA Center were suitable products available (from libraries. Our hope was that the libraries commercial or other sources) to meet the would both participate as users in the beta requirements. In July 1991, the test and assist in assembling a good development team was assembled and sample of end-users by displaying the conceptual design began; in November system in an open area. However, network 1991, technical design started. connectivity requirements eliminated most Development of the software began in of the Center libraries that wanted to December of 1991, with a due date of June participate in the beta test. Only three beta 30, 1992 for demonstration of the alpha testers came from the libraries or library version. In February, 1991, the schedule referrals; the majority of the beta testers was changed, to have a demonstration of were people who saw NAM demonstrated the system at the April, 1992 STI by a colleague or at a trade show and Managers' Meeting. On April 28, a wished to participate in testing. working version of the NAM was Participants for the beta test were limited demonstrated to attendees at that meeting. to NASA employees and contractors who were U.S. citizens. During the summer of 1992, additional disk drives were procured to provide the As word of the prototype spread, the NAM additional space for user accounts; during team began receiving requests for beta test this time, the alpha version was revised to accounts. This resulted in gradual growth include more tools and to make the in the number of beta testers to a total of software more robust. Also during this forty by the end of the test period, instead time, many vendors' versions of the X of a sample of fifty testers for the entire

19 serversoftwarefor MacintoshandPC II.C.6. Statistics on Responses platformswereevaluated,andthe packagesto besupportedwereselected. Users were electronically mailed a Internaltestingwasperformedby the questionnaire about the prototype developmentteamandJ'VI"users,anda application. A copy of the questionnaire is user'smanualwasproduced. in Appendix A. The answers to the questionnaire (with names omitted) are Thebetaversionof thesoftwarewas provided in Appendix B. completedin thefall of 1993,andbeta testersweresolicitedin November1993. User feedback was collected via electronic Thesix-monthtestingperiodbegan mail responses. Unfortunately, only a December1, 1992andwascompleted small number of the beta testers responded May 31, 1993.Userswereadded to the questionnaire. The collected gradually,sincethemajorityof theusers responses were tallied and analyzed. nominatedthemselvesfor thebetatest afterseeingtheNAM onacolleague's As illustrated in Figure 4, the most widely desktopor atanexhibit.Thus,mostusers used portion of NAM was the Data formally evaluatedtheNAM overaperiod Sources icon. The graph shows statistics shorterthansix months.At theendof the based on actual number of transactions betatestperiod,usersweresentevaluation performed during the official beta test formsvia electronicmail for responseby period. Bulletin Boards, which were thesamemechanism. actually the Internet tools, and others, which were the weather maps, were the II.C.5. What Did We Provide? next most popular items.

We provided users with an account on our 59% Sun processor (nova.sti.nasa.gov). They 100o 9o0 executed the NAM GUI (both the NAM 8o0 client and server) on nova, and displayed it 7o0 to their local workstation over the Internet. 600 500 We provided electronic mail and telephone 400 30O support to users needing assistance with 10% 13% 13% 20O NAM operation. We also provided initial 100 5% on-site support for users installing X o server software on personal computers or Macintosh workstations. After a number of users had begun using the NAM with no training from the development team, we visited some user sites to offer them Figure 4. NAM Use by Icon training, user manuals, and demonstrations to other potential users. We provided each user with a user manual if they wanted one.

20 X.500 More Useful Than Electronic CHAPTER THREE- Phonebook The developers stopped updating the Lessons Learned electronic phonebook because it required them to continually obtain electronic versions of the phonebook from each III.A. DEVELOPERS' center. Each centers' data was in a FINDINGS different format, which made this difficult. Using each centers' X.500 III.A.1. Findings During Development online directory for the phonebook and Testing information proved to be more useful, since NASA has made a commitment to Local Availability of NAM GUI keep information in these directories current. It was found, however, that Developers found the biggest problem to be the slowness of the interface when the people didn't select X.500 under peer application was run remotely (as was locators because they didn't know what it done in the beta test). The problem was did; instead they chose the NASA Phonebook option. The X.500 option that we were running an X application should have been renamed to reflect its over a wide area network (WAN), which function. caused the throughput to be very slow. If the X application approach is to be successful, local concentrations of X- Limited Internet Connectivity to Libraries based NAM users should be served by a local machine capable of running the Before the beta test phase began, it was NAM GUI to attempt to maintain the assumed that each NASA library would high-bandwidth requirement between the have a running version of the NAM X application and the X display on a located in an open area of the library. It was soon learned, however, that most of local area network (LAN). This would the libraries did not have access to the require that at least one machine be Internet from local machines. Some located at each site that would be libraries did have access, but their LAN capable of running the NAM GUI for administrators did not want X people who can not run the GUI on their desktop machine (i.e., PCs and applications running locally because Macintosh computers). Users with UN/X- they thought they would cause networks based machines with X 11R5 and Motif bottlenecks. This lack of connection with libraries placed limits on the Beta Test. installed would be best served by installing the application on their own workstations. Lack of Adequate Platforms Eliminated Some Testers Native Clients are Needed for Each Many people expressed great interest in Supported Platform becoming beta testers, but could not due so because their workstations did not The deployment of the prototype to the different NASA centers pointed out the meet the minimum system requirements. difficulty in getting an X-Window The X Server software required Microsoft Windows on DOS machines, system running reliably in many different hardware environments. The with at least 8 MB of memory and a support of IBM-PCs and clones was VGA monitor. Many systems, especially in the libraries, did not meet these especially difficult due to the many differences in hardware/software requirements. Macintosh platforms with small monitors and low memory were configurations encountered in the beta also eliminated. test community.

21 PC Xserver Software Selection III.B. USERS' FINDINGS Cumbersome A study was done of existing Xserver Testers Loved It! software to determine the one which was The most common comment was "This is best suited to run the NAM application. great!" The testers were very happy to The testing and selection of this software have access to NAM, and many have took longer than planned, and the selected incorporated it's use into their everyday packages still had occasional bugs. work. That's not to say that there is no room for improvement. During the process Dial-in connection to the NAM was of beta testing, users responded with supported for demonstrations and exhibits. comments and recommendations for the XRemote performed better than the other modification of the functional serial protocols, PPP and SLIP, for dial-in requirements for NAM. connections to the NAM, using a 9600 baud modem. XRemote is a proprietary Slow Response Time communications protocol developed by The most often heard comment from users NCD. It falls under a technology category was that the NAM application was too referred to as Low-Bandwidth X (LBX). A slow. The NAM GUI used by the beta standard for LBX is expected in X1 l/R6, testers ran from a machine in Crystal City, to be released in early 1994. Virginia. The GUI was then displayed on the user's workstation over the Internet. Users Like the Expand Feature This meant that every keystroke and every The expand feature allowed users to search click of the mouse button had to go over for an author or rifle, and choose from a the Internet and back for the user to see list of terms that were close to the one anything happen. As a result, the searched. Users liked this feature because application was slow. they did not have to know exactly how to spell an author's name or how it was Type of Training Desired entered into the database. Generally, the testers felt personal training from a knowledgeable user, plus a III.A.2. Findings From Log Files and combination of online instruction (tutorials Monitoring and more extensive help screens) was the best training environment. They felt the Intermediate Form Used Most help screens in the beta test version were Results showed that the Intermediate not very helpful. query form, which allowed users to query on words or phrases found in the abstracts More Sources of Information Needed of documents, was used more than the Most of the users found the NAM novice or expert. The most common type interface so useful that they wanted to add of query was based on Author name, more data types and sources of followed by Subject/Keyword queries. The information to those currently available. Intermediate form supported both these On average, each user had one or two query types. additions to the information sources provided through the prototype. Types of Electronic Phonebooks Popular information requested were as follows: Electronic phonebooks were widely used. This capability will be enhanced as more • Full text corporate and national electronic phone • All NASA papers and technical reports books and directories become available. • Product reviews and descriptions The directories need not be global to be • Science Citation Index useful. Often the organizational level • Readers' Guide to Periodicals directories were used. • Standard reference works • NASA program descriptions • NEXUS, LEXIS, DIALOG

22 • GeoRef Full Text Retrieval • Non-textualdatabases Once abstracts are retrieved users would • NASA budgetinformation like to access full text documents. This has • Physicalpropertiestables;flow been a requirement mentioned by a properties majority of the users and should be given • Databaseof peopleandtheirexpertise high consideration. • NASA satellitedata(EOSDIS, NSSDC) Search and Retrieval Techniques • NASA softwareavailablefor reuse Users want to expand their search and • COSMICcatalogue retrieval techniques to include tools other • Educationalsoftware than Boolean logic, such as relevance • Images feedback, natural language queries, and • Planetaryandlunaryimagesavailable spatial, range, and proximity searching. from JPL • Publicity imagesavailablefrom Public User Customization Affairs offices Users want the ability to customize the • Propertydatabase(flow database) query screen to suit their individual search • Numericaldatabases needs. • Citations index • Commercial information (Thomas' Local Printing Requested Register) Once information is retrieved, users need • NASA Thesaurus the option to print the results locally at • DIALOG their site. Currently the system directs • CIA word FACT Book output to a printer attached to the NAM • Softlib server in Crystal City.

Single Query Against Multiple Sources Action Items Needed for Short Citations Users would like an option to have the Options currently available for long system determine appropriate remote citations, such as print, save, and FAX, are host(s) for a topic, and have the system needed on the short citations screen as execute the query against the appropriate well. Many users know a document is source(s). Users should have control of the needed simply by looking at the title and querying process in all phases (for do not want to view the long abstract example, to edit the list of remote sources before acting on it. chosen for execution, or not; to view intermediate results, or not, etc.) Perform Actions on Multiple Documents Selective Dissemination of Information Users would like to be able to act on more Some users would like the option of than one document at a time. For instance, creating a standing topic of interest to be if they found 50 documents through a executed automatically or at the user's search in their area, they would like to be request (also known as selective able to mail them all to themselves or dissemination of information). choose more than one at a time.

Usenet News Filter Post Processing Tools Some users thought it would be useful to Users requested that post processing tools be able to query Usenet News categories be available to allow specific for specific information so they would not transformations to be performed on data have to search through many messages to obtained from searches. An example given find something of interest. is a duplicate elimination process that would delete multiple instances of the same data found in multiple sources.

23 Data Visualization week per year to several weeks per year, Many sites store data that is non-textual in and a high of $20,000 per year. format. The ability to have various file formats, such as postscript files or Uses of Desktop Information Access numerical data, translated automatically Users found that they used NAM mostly to into a readable image is desired by users. stay current in their field or prepare a presentation or paper. The next most Language Translation important use was to find an expert for Users need to translate foreign language collaboration or to help solve a problem. files as they are transported as well as the After that the most popular use was to terms on which they are searched. prepare/refine a project proposal. Others used the NAM to train library patrons or to Graphical User Interface (GUI) to find references via author search. Databases Easy to Use The GUI concept was applied to Predicted Use of NAM bibliographic database queries by a form Users were asked to predict the frequency on which users filled in blanks with which they would use the various corresponding to attributes of the remote facilities provided by the prototype. Users database. The forms were the same predicted that they would use all facilities, regardless of the remote database. Users with a frequency of use for different had no difficulty using the forms for single facilities ranging from once per month to queries and found them to be much easier several times per day. than learning the query language native to the database being searched. Professional Users predict that they would use mall and searchers felt that the forms could be made bulletin boards most frequently, followed more effective by the addition of tools to by access to data sources (in order of use the remote source's Thesaurus and frequency: ARIN, and Inspec) followed by Frequency functions when available. utilities and peer locators.

Minimum Training Required III.C. PUBLIC DEMONSTRATIONS The NAM Prototype has been used AND TRADE PRESS REACTIONS successfully by NASA engineers with no prior training other than a demonstration In January, 1993, the STI Program exhibit lasting less than one-half hour. The unique staff began to demonstrate the NASA combination of tools to access internal and Access Mechanism at various trade shows, external information, formal and informal exhibits, and conferences throughout the sources, peer location and Internet utilities United States. Public reactions to the is applicable in various user environments. NAM varied with the particular exhibit Users liked the fact that they did not need attendees. a lot of training to use the NAM. Audiences consisting mostly of Electronic Phonebooks Popular researchers and NASA employees or Users liked the digital phonebooks to find contractors were very interested in the information about their peers and found Data Sources portion of NAM. They were them very useful. They especially found thrilled to find that someone was trying to the email addresses helpful. make commonly used databases such as STN and RECON user friendly. Most Desktop Access to Infromafion Saves audiences said they currently went to their Staff Time site library to have searches done for them, Users were asked to estimate the time and they disliked having to physically go and/or money they would save per year if there and then wait for the search being they had the NAM available to them from performed. Many people did not know their desktop. Individual estimates of what RECON was; they simply knew that savings ranged from a low of at least one

24 their librarian found information from the NAM project, the systems on which it some database inside NASA. After a short runs, and the data source portion of the demonstration of the NAM they were very software. It mentioned the other functions impressed with the simplicity, and the next of NAM but did not go into great detail question was always, "How can I get it?" about them. This article generated interest, or "When will this be available to the but did not give a point of contact to the public?" readers. Some people still managed to track down the STI program by asking Exhibits that were tailored towards new NASA employees how to contact the technology brought different responses programmers listed in the article. from attendees. These audiences were more interested in the Internet tools than On July 5, 1993 Computerworld published the database search mechanisms. They an article titled, "NASA's GUI Makes the were excited to see that they could have Internet User Friendly." (see tools such as WADS, Gopher, Usenet and appendix).This article focused on the World Wide Web available to them modularity of the NAM software and through one single application. They also graphical user interface to the Internet. wanted to know how they could get NAM The article also informed readers that they put on their desktop workstation. could learn more about NAM by sending email to [email protected], which Although there was a great deal of interest forwarded the messages to all members of from conference attendees in becoming the NAM team. This article generated beta testers for NAM, many of them did interest from over 250 readers who wanted not qualify. Some conferences had many to know when NAM would be available to attendees from commercial firms to which the public and how they could learn more we could not supply the software. Many of about it. Those interested received the people did not have Internet access at instructions on how to download a their desktop, so they would not be able to technical NAM paper using FTP or a use NAM. Others became uninterested gopher client. More people are getting when they found out they needed to connectivity, but need help navigating purchase the Xserver software to use their way to useful information. Many NAM on a PC or Macintosh. Generally thought that having several tools available comments were positive from all groups, through one piece of software was an and they wanted to know when the excellent idea and they wanted to try it software would be publicly available. themselves. The NAM team was very surprised to learn that most of the interest As more people learned about the NAM, in the NAM software was based on the interest continued to grow. On May 24, tools, not the database search utilities as 1993 Government Computer News planned. Tools such as WADS, gopher, and published an article titled, "NASA's WWW are publicly available to everyone, Homegrown GUI Scores Big With Beta but many people do not know how to Testers." (see appendix). This article obtain them and make them run. focused primarily on the background of

25 strategy any more complicated to the CHAPTER FOUR- novice user. The native mode will be available for those expert users of Options RECON, STN, or DIALOG. The expert screen will be dropped because it is somewhat limiting for true expert users IV.A. CREATE NAM-Lite who want to search using the native system query language. The existing NAM application could be modified so the NAM GUI could be Basic peer locator tools will still be distributed to users. The server portions of available with NAM-Lite. The digital NAM can still be run in a more controlled phonebooks will be dropped because they environment. It is recommended that the are too difficult to keep current. The X.500 following changes be made to the current service will be available and possibly NAM system to create NAM-Lite: renamed digital phonebook. Other basic services such as finger, netlib, and whois • User authentication will remain the same. Adding a new • Limit to RECON, STN and DIALOG service class such as NetFind would connectivity greatly enhance the user's capabilities to • Only intermediate and native screens locate individuals. • Basic peer locator tools provided • Top level icons modified The top level icons will be modified with a • Group/Set operations whole new look to differentiate them from • Screens for new account information the current version of NAM. There will • Automatic link to thesaurus only be three main buttons, which will be • Source locator redone Data Sources, Peer Locator, and Tools. • Added Peer Locator tools The tools button will be a user-defined button with which users can link local The NAM-Lite program should still applications, such as ernail, WWW, WAIS contain the functionality of RECON and and gopher. STN. Adding DIALOG as a database source would fill the majority of user NAM-Lite should include the capability to requests for external sources. User perform group operations. Users will be authentication will need to be built into the able to select all or multiple sets of data system to allow a user to maintain and and perform group operations on them modify his/her own passwords and userid such as printing, faxing, or mailing. information. The user will have the option of using STN, DIALOG and RECON, as An automatic link to the thesaurus will be with the current system, but if they do not implemented in NAM-Lite. Users will be have an existing account they will be able to search on terms, but if they are presented with an informative page on unclear about a term they can how to get accounts either online or by automatically bring up a thesaurus to assist contacting the respective agency. Once an them. account has been established, the user will be transparently connected to the remote The source locator needs to be updated to system as with the current version of connect to accessible file collections and NAM. reflect access to collections by user id. Users would be able to connect to NAM-Lite should only limit the search classified information if their user id was form to the intermediate and native of a certain class. screens. The novice screen is unnecessary because the intermediate screen allows for Once NAM-Lite is created it can be more complex searches by the experienced distributed to the NASA community. user but does not make a simple search

26 NAM-Lite would replace the current Since the QUEST system takes as its version of the NAM that is being run origins the same software that RECON remotely by users; it would be run locally uses, it is anticipated that modification of to obtain maximum speed, which has been the source code of BRAQUE to work with a large problem. _ RECON would not be too extensive. This would give the STI Program a quick and The same NAM-Lite described above inexpensive PC platform native client. The could be made available to the public. The ESA folks have stated that they would be user authentication process, which gives willing to give the STI program a copy of instructions on how to obtain an account, the source code for this purpose. may spark interest for potential users at universities and research institutions to obtain RECON accounts. IV.D. CREATE FRONT END FOR INTERNET TOOLS The GUI should be ported to other UNIX variants such as IRIX, HP-UX, and AIX. The icon of the NAM called Bulletin This would allow for a larger community Boards provided the user with a front end of potential users to take advantage of the to public domain software such as WWW, NAM-Lite. Archie, gopher, and WAIS. These applications proved to be a very popular IV.B. USE WORLD WIDE WEB portion of NAM and could be isolated into FORMS a separate GUI providing easy access to commonly used Internet tools. Implement the functions of the formal data sources access using the forms functionality of Mosaic/WWW. This will The entire design of the NASA Access allow us to leverage from the work done at Mechanism needs to be reconsidered, the National Center for Supercomputing redesigned, and reimplemented. A new Applications (NCSA) on Mosaic. This design specification should be written to approach also allows the limited support alleviate problems with the current system capabilities of the STI Program to and to take advantage of new technology. concentrate on the service aspects of the An Object Oriented Design (OOD) should NAM rather than concentrating on the be used. A GUI that may be easily tailored development of native clients. Currently, to individuals or small groups needs NCSA provides native clients for UNIX should be provided. The GUI should be (X 1 1/OSF Motif), MS-Windows, and implemented natively under UNIX/X, MacOS platforms. MacOS, and Microsoft Windows. New tools and services need to be provided to IV.C. CREAT NATIVE CLIENTS help users locate and access the data WITH SMALL REWRITE sources they need.

Native clients could be written for PC IV. F. THROWAWAY NAM (DOS and Windows) and Macintosh platforms that would provide the same The first option is to remove all access to functionality as the current NAM system. the current system. What has been learned The European Space Agency (ESA) has from the prototype can be incorporated developed a MS-Windows based product into the NASA STI Program's RECON called BRAQUE (BRowse And QUEry). Replacement system. This is not a viable This system allows PC users connected to option unless the RECON Replacement is either a TCP/IP Internet or via an implemented in a timely fashion. asynchronous modem to connect to ESA's QUEST system and perform searches using a GUI query-by-forms capabilities.

27 IV.G. OTHER CONSIDERATIONS

Issues of distribution, support, and access rights need to be considered. Any user community to whom we provide access to a potential new version of NAM needs to be made aware of data access restrictions.

28 consistent from client to client. For other CHAPTER FIVE - applications that we have integrated like gopher, WAIS, email, etc. we should use Recommendations the best native client that is available in the public domain. V.A. SHORT TERM V.C. MANAGEMENT Both the NAM-Lite version and a RECOMMENDATIONS WWW/Mosaic Forms version of NAM It is recommended that the current NAM GUI should be developed and made available to the NASA user community as prototype system be modified in a timely manner so that it can become available to soon as possible. These recommendations suggest interim measures designed to the NASA user community as quickly as serve our user community until the formal possible. Functions that are out of date or RECON replacement is made available. not used will be removed from the system, and remaining functions will be updated as The NAM-Lite implementation would be described in the previous section. This made available in both source and binary new version of the product will be known forms to allow maximum outside exposure as NAM-Lite. Once the product is ready and encourage outside enhancements. The for distribution, the team should do use of either COSMIC and/or anonymous whatever is needed to get the libraries to FTP as distribution medium sites is use the system. The NAM-Lite system strongly encouraged. should act as an interim system until the RECON Replacement system is in place. The WWW/Mosaic Forms version, on the Once the RECON Replacement system is other hand, does not require a distribution in place, the Program will need to evaluate medium, as the form would simply be the need for keeping NAM-Lite made available on the STI's WWW server. operational. This would be a HTML document that would be interpreted by WWW clients Once an operational system is in place, such as Mosaic. support of the NAM product should be transferred to the Information Services Operational support of the NAM-Lite Section of the STI Program. Training will version should be provided by the be supplied for the Help Desk staff at Information Services Section of the STI CASI so they can handle the questions Program. Maintenance of the code should they receive on a daily basis. be limited to bug fixes and minor enhancements only. Functions that provide users with an interface to the Internet utilities should be Versions of NAM-Lite must be ported to isolated and distributed as a separate other common platforms (UNIX, PCs and system via COSMIC. Mac's). It is also recommended that the NASA STI V.B. LONG TERM Program's Engineering Review Board discuss the role NASA wants to play in Native clients for MS-Windows, providing a system like NAM to the user MacOS, and Xll community. Does the Program want to The possibility of modifying the support the system forever or distribute the ESA/BRAQUE software to work for MS- software and let the Centers and Program Windows platform should be researched. Offices do as they want? This is a strategy Native clients for Macintoshes also need to question which will need more discussion. be developed. The parts of the current client that are unique should remain

29 archie GLOSSARY A system to automatically gather, index, and serve information on the Interact. The initial implementation of agent _ _ archie provided an indexed directory In the client-server model, the part of of filenames from all anonymous FTP the system that performs information archives on the Interact. Later versions preparation and exchange on behalf of provide other collections of a client or server application. information. _

American Standard Code for archive site Information Interchange (ASCII) A machine that provides access to a A standard character-to-number collection of files across the Internet. encoding widely used in the computer An "anonymous FTP archive site," for industry. example, provides access to this material via the FTP protocol. anonymous FIT Anonymous VI'P allows a user to authentication retrieve documents, files, programs, The verification of the identity of a and other archived data from anywhere person or process. in the Internet without having to establish a userid and password. By backbone using the special userid of The top level in a hierarchical network. "anonymous" the network user will Stub and transit networks that connect bypass local security checks and will to the same backbone are guaranteed to have access to publicly accessible files be interconnected. on the remote system. bandwidth AppleTalk Technically, the difference, in Hertz Apple Computer's suite of protocols (Hz), between the highest and lowest that enables the hardware and software frequencies of a transmission channel. on an AppleTalk network to interact However, as typically used, bandwidth and to route data. is the amount of data that can be sent through a given communications application circuit. A program that performs a function directly for a user. FTP, mail, and Berkeley Software Distribution (BSD) Telnet clients are examples of network Implementation of the UNIX operating applications. system and its utilities developed and distributed by the University of application layer California at Berkeley. "BSD" is The top layer of the network protocol usually preceded by the version stack. The application layer is number of the distribution, e.g., "4.3 concerned with the semantics of work BSD" is version 4.3 of the Berkeley (e.g., formatting electronic mail UNIX distribution. Many Intemet hosts messages). How to represent that data run BSD software, and it is the and how to reach the foreign node are ancestor of many commercial UNIX issues for lower layers of the network. implementations.

Application Program Interface (API) Bulletin Board System (BBS) A set of calling conventions which A computer, and associated software, define how a service is invoked which typically provides electronic through a software package. messaging services, archives of files, and any other services or activities of

30 interest to the bulletin board system's Corporation which is widely is use operator. Although BBSs have today traditionally been the domain of hobbyists, an increasing number of Defense Advanced Research Projects BBSs are connected directly to the Agency (DARPA) Internet, and many BBS's are currently An agency of the U.S. Department of operated by government, educational, Defense responsible for the and research institutions. development of new technology for use by the military. DARPA (formerly client known as ARPA) was responsible for A computer system or process that funding much of the development of requests a service of another computer the Internet we know today, including system or process. A workstation the Berkeley version of UNIX and requesting the contents of a file from a TCP/IP. file server is a client of the file server. Defense Data Network (DDN) client-server model A global communications network A common way to describe the serving the U.S. Department of paradigm of many network protocols. Defense composed of MILNET, other Examples include the name- portions of the Internet, and classified server/name-resolver relationship in networks that are not part of the DNS and the file-server/file-client Internet. The DDN is used to connect relationship in NFS. military installations and is managed by the Defense Information Systems connection-oriented Agency. The data communication method in which communication proceeds Defense Data Network Information through three well-defined phases: Center (DDN NIC) Often called"The connection establishment, data NIC," theDDN NIC's primary transfer, and connection release. TCP responsibilityisthe assignment of is a connection-oriented protocol. Intemet network addressesand Autonomous System numbers, the connectionless administrationof the rootdomain, and The data communication method in providinginformationand support which communication occurs between servicesto the DDN. Itisalsoa hosts with no previous setup. Packets primary repositoryforRFCs. between two hosts may take different routes, as each is independent of the dialup other. UDP is a connectionless A temporary, as opposed to dedicated, protocol. connection between machines established over a standard phone line. datagram A self-contained, independent entity of Directory Access Protocol data carrying sufficient information to X.500 protocol used for be routed from the source to the communication between a Directory destination computer without reliance User Agent and a Directory System on earlier exchanges between this Agent. source and destination computer and the transporting network. Directory System Agent (DSA) The software that provides the X.500 DECNET Directory Service for a portion of the A proprietary network communication directory information base. Generally, protocol by Digital Equipment each DSA is responsible for the

31 directoryinformationfor asingle mail is one of the most popular uses of organizationor organizationalunit. the Internet.

Directory User Agent (DUA) email address The software that accesses the X.500 The domain-based or UUCP address Directory Service on behalf of the that is used to send electronic mail to a directory user. The directory user may specified destination. be a person or another software element. Ethernet A 10-Mb/s standard for LANs, initially Distributed Computing Environment developed by Xerox and later refined (DCE) by Digital, Intel and Xerox (DIX). All An architecture of standard hosts are connected to a coaxial cable programming interfaces, conventions, where they contend for network access and server functionality (e.g., naming, using a Carrier Sense Multiple Access distributed file system, remote with Collision Detection (CSMA/CD) procedure call) for distributing paradigm. applications transparently across networks of heterogeneous computers. Federal Information Exchange (FIX) Promoted and controlled by the Open One of the connection points between Software Foundation (OSF), a the American governmental interacts consortium led by Digital, IBM, and and the Internet. Hewlett Packard. Fiber Distributed Data Interface (FDDI) distributed database A high-speed (100Mb/s) LAN A collection of several different data standard. The underlying medium is repositories that looks like a single fiber optics, and the topology is a dual- database to the user. A prime example attached, counter-rotating token ring. in the Internet is the Domain Name System. file transfer The copying of a file from one Domain Name System (DNS) computer to another over a computer The DNS is a general purpose network. distributed, replicated, data query service. The principal use is the lookup File Transfer Protocol (FTP) of host IP addresses based on host A protocol that allows a user on one names. The style of host names now host to access and transfer files to and used in the Intemet is called "domain from, another host over a network. name," because they are the style of Also, FrI'p is usually the name of the names used to look up anything in the program the user invokes to execute DNS. Some important domains are the protocol. It is defined in STD 9, .COM (commercial), .EDU RFC 959. (educational), .NET (network operations), .GOV (U.S. government), finger and .MIL (U.S. military). Most A program that displays information countries also have a domain. For about a particular user, or all users, example, .US (United States), .UK logged on the local system or on a (United Kingdom), .AU (Australia). remote system. It typically shows full name, last login time, idle time, Electronic Mail 0gmail) terminal line, and terminal location A system whereby a computer user can (where applicable). It may also display exchange messages with other plan and project files left by the user. computer users (or groups of users) via a communications network. Electronic

32 gateway International Organization for Theterm "router"is nowusedin place Standardization (ISO) of theoriginal definitionof "gateway". A voluntary, non-treaty organization Currently, a gateway is a founded in 1946 that is responsible for communications device/program that creating international standards in passes data between networks having many areas, including computers and similar functions but dissimilar communications. Its members are the implementations. This should not be national standards organizations of the confused with a protocol converter. By 89 member countries, including ANSI this definition, a router is a layer 3 for the U.S. (network layer) gateway, and a mall gateway is a layer 7 (application layer) internet gateway. While an internet is a network, the term "internet" is usually used to refer gopher to a collection of networks A distributed information service that interconnected with routers. makes available hierarchical collections of information across the lnternet Internet. Gopher uses a simple protocol (Note the capital "I.") The Internet is that allows a single Gopher client to the largest internet in the world. It a access information from any accessible three-level hierarchy composed of Gopher server, providing the user with backbone networks (e.g., NSFNET, a single "Gopher space" of MILNET), mid-level networks, and information. Public domain versions of stub networks. The Internet is a the client and server are available. multiprotocol interact.

Government OSI Profile (GOSIP) internet address A subset of OSI standards specific to A IP address that uniquely identifies a U.S. Government procurements, node on an interact. An Internet designed to maximize interoperability address (capital 'T') uniquely identifies in areas where plain OSI standards are a node on the Internet. ambiguous or allow excessive options. lnternet Protocol lIP) host The Intemet Protocol, defined in STD A computer that allows users to 5, RFC 791, is the network layer for communicate with other host the TCP/IP Protocol Suite. It is a computers on a network. Individual connectionless, best-effort packet users communicate by using switching protocol. application programs, such as electronic mail, Telnet, and FTP. Internetwork Packet eXchange (IPX) Novell's protocol used by Netware. A hostname router with IPX routing can The name given to a machine. interconnect LANs so that Novell Netware clients and servers can Interagency Interim National Research communicate. and Education Network (IINREN) An evolving operating network interoperabiHty system. Near term (1992-1996) The ability of software and hardware research and development activities on multiple machines from multiple will provide for the smooth evolution vendors to communicate meaningfully. of this networking infrastructure into the future gigabit NREN. Kermit A popular file transfer protocol developed by Columbia University.

33 Because Kermit runs in most operating requests sent via email. Internet environments, it provides an easy examples include Almanac and netlib. method of file transfer. Kermit is NOT Mail servers have also been used in the same as FTP. Bitnet to provide FTP-like services. See also Electronic Mail, File Transfer knowbot Protocol. An experimental directory service. Multipurpose Internet Mail Extensions layer (MIME) Communication networks for An extension to Interact email that computers may be organized as a set of provides the ability to transfer non- more or less independent protocols, textual data, such as graphics, audio each in a different layer (also called and fax. It is defined in RFC 1341. level). The lowest layer governs direct host-to-host communication between National Institute of Standards and the hardware at different hosts; the Technology (NIST) highest consists of user applications. United States governmental body that Each layer builds on the layer beneath provides assistance in developing it. For each layer, programs at different standards. Formerly the National hosts use protocols appropriate to the Bureau of Standards. layer to communicate with each other. TCP/IP has five layers of protocols; National Research and Education OSI has seven. The advantages of Network (NREN) different layers of protocols is that the The NREN is the realization of an methods of passing information from interconnected gigabit computer one layer to another are specified network devoted to High Performance clearly as part of the protocol suite, Computing and Communications. and changes within a protocol layer are prevented from affecting the other National Science Foundation (NSF) layers. This greatly simphfies the task A U.S. government agency whose of designing and maintaining purpose is to promote the advancement communication programs. of science. NSF funds science researchers, scientific projects, and listserv infrastructure to improve the quality of An automated mailing hst distribution scientific research. The NSFNET, system originally designed for the funded by NSF, is an essential part of Bitnet/EARN network. See also Bitnet, academic and research European Academic Research communications. It is a high speed Network, mailing list. "network of networks" that is hierarchical in nature. At the highest Local Area Network (LAN) level, it is a backbone network A data network intended to serve an currently comprising 16 nodes area of only a few square kilometers or connected to a 45Mb/s facility that less. Because the network is known to spans the continental United States. cover only a small area, optimizations Attached to that are mid-level can be made in the network signal networks and attached to the mid- protocols that permit data rates up to levels are campus and local networks. lOOMbls. See also Ethemet, Fiber NSFNET also has connections out of Distributed Data Interface, Wide Area the U.S. to Canada, Mexico, Europe, Network. and the Pacific Rim. The NSFNET is part of the Internet. mail server A software program that distributes files or information in response to

34 network Open Systems Interconnection (OSI) A computer network is a data A suite of protocols, designed by ISO communications system that committees, to be the international interconnects computer systems at standard computer network various different sites. A network may architecture. be composed of any combination of LANs or WANs. OSI Reference Model A seven-layer structure designed to network address describe computer network The network portion of an IP address. architectures and the way that data For a class A network, the network passes through them. This model was address is the first byte of the IP developed by the ISO in 1978 to address. For a class B network, the clearly define the interfaces in network address is the first two bytes multivendor networks and provide of the IP address. For a class C users of those networks with network, the network address is the conceptual guidelines in the first three bytes of the IP address. In construction of such networks. each case, the remainder is the host address. In the Intemet, assigned packet network addresses are globally unique. The unit of data sent across a network. See also: Intemet. "Packet" is a generic term used to describe a unit of data at all levels of Network File System (NFS) the protocol stack, but it is most A protocol developed by Sun correctly used to describe application Microsystems and defined in RFC data units. See also datagram. 1094 that allows a computer system to access files over a network as if they Packet lnterNet Groper (PING) were on its local disks. This protocol A program used to test reachability of has been incorporated in products by destinations by sending them an ICMP more than two hundred companies, and echo request and waiting for a reply. is now a de facto Internet standard. The term is used as a verb: "Ping host X to see if it is up!" Network Information Center (NIC) A NIC provides information, Point-to-Point Protocol ('PPP) assistance, and services to network The Point-to-Point Protocol, defined in users. RFC 1171, provides a method for transmitting packets over serial point- Network Information Services (NIS) to-point links. A set of services, generally provided by a NIC, to assist users in using the port network. A port is a transport layer demultiplexing value. Each application Network News Transfer Protocol has a unique port number associated (NNTP) with it. See also Transmission Control A protocol, defined in RFC 977, for Protocol. the distribution, inquiry, retrieval, and posting of news articles. postmaster The person responsible for taking care node of electronic mail problems, answering An addressable device attached to a queries about users, and other related computer network. See also: host, work at a site. router.

35 protocol organizations such as CCITT and A formal description of message ANSI. formats and the rules two computers must follow to exchange those route messages. Protocols can describe low- The path that network traffic takes level details of machine-to-machine from its source to its destination. Also, interfaces (e.g., the order in which bits a possible path from a given host to and bytes are sent across a wire) or another host or destination. high-level exchanges between allocation programs (e.g., the way in router which two programs transfer a file A device that forwards traffic between across the Intemet). networks. The forwarding decision is based on network layer information protocol stack and routing tables, often constructed A layered set of protocols that work by routing protocols. together to provide a set of network functions. routing The process of selecting the correct queue interface and next hop for a packet A backup of packets awaiting being forwarded. processing. Serial Line IP (SLIP) remote login A protocol used to run IP over serial Logging in on a remote computer, lines, such as telephone circuits or RS- using a protocol over a computer 232 cables, interconnecting two network, as though locally attached. systems. SLIP is defined in RFC 1055.

Remote Procedure Call (RPC) server An easy and popular paradigm for A provider of resources (e.g., file implementing the client-server model servers and name servers). of distributed computing. In general, a request is sent to a remote system to Simple Mail Transfer Protocol (SMTP) execute a designated procedure, using A protocol, defined in STD 10, RFC arguments supplied, and the result 821, used to transfer electronic mail returned to the caller. There are many between computers. It is a server-to- variations and subtleties in various server protocol, so other protocols are implementations, resulting in a variety used to access the messages. of different (incompatible) RPC protocols. SLIP See Serial Line IP. Request For Comments (RFC) The document series, begun in 1969, snail mail that describes the Internet suite of A pejorative term referring to the U.S. protocols and related experiments. Not Postal Service. all (in fact very few) RFCs describe Internet standards, but all Internet TCP/IP Protocol Suite standards are written as RFCs. The Transmission Control Protocol over RFC series of documents is unusual in Intemet Protocol. This is a common that the proposed protocols are shorthand that refers to the suite of forwarded by the Internet research and transport and application protocols that development community, acting on runs over IP. their own behalf, as opposed to the formally reviewed and standardized protocols that are promoted by

36 Telnet address, phone number, and email Telnet is the Intemet standard protocol address. for remote terminal connection service. It is defined in STD 8, RFC 854 and Wide Area Information Servers (WAIS) extended with options by many other A distributed information service that RFCs. offers simple natural language input, indexed searching for fast retrieval, _,Transmission Control Protocol (TCP) and a "relevance feedback" mechanism An Internet Standard transport layer that allows the results of initial protocol defined in STD 7, RFC 793. It searches to influence future searches. is connection-oriented and stream- Public domain implementations are oriented, as opposed to UDP. available.

Usenet Wide Area Network (WAN) A collection of thousands of topically A network, usually constructed with named newsgroups, the computers that serial lines, which covers a large run the protocols, and the people who geographic area. read and submit Usenet news. Not all Internet hosts subscribe to Usenet and World Wide Web (WWW or W3) not all Usenet hosts are on the Intemet. A hypertext-based, distributed information system created by virtual circuit researchers at CERN in Switzerland. A network service that provides Users may create, edit, or browse connection-oriented service regardless hypertext documents. The clients and of the underlying network structure. servers are freely available.

white pages X The Internet supports several databases X is the name for TCP/IP based that contain basic information about network-oriented window systems. users, such as email addresses, Network window systems allow a telephone numbers, and postal program to use a display on a different addresses. These databases can be computer. The most widely- searched to get information about implemented window system is X11, a particular individuals. Because they component of MIT's Project Athena. serve a function akin to the telephone book, these databases are often XA00 referred to as "white pages". The CCITT and ISO standard for electronic mail. It is widely used in WHOIS Europe and Canada. An Intemet program that allows users to query a database of people and other X.500 Internet entities, such as domains, The ccrlT and ISO standard for networks, and hosts, kept at the DDN electronic directory services. See also NIC. The information for people white pages, Knowbot, WHOIS. shows a person's company name,

37 REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188

1. AGENCY USE ONLY (leave blank) 3. REPORT TYPE AND DATES COVERED Technical Memorandum 2. REPORTJuly 1994DATE

4. TITLE AND SUBTITLE 5. FUNDING NUMBERS NASA Access Mechanism - Lessons Learned Document

6. AUTHOR(S) Lisa Burdick, Rick Dunbar, Denise Duncan, Curtis Generous, Judy Hunter, John Lycas, Ardeth Taber-Dudas

7. PERFORMINGORGANIZATIONNAME(S)ANDADDRESS(ES) 8. PERFORMING ORGANIZATION NASA STI Program REPORT NUMBER Code JTT

9. SPONSORING/ MONITORINGAGENCYNAME(S)ANDADDRESS(ES) 10. SPONSORING / MONITORING AGENCY National Aeronautics and Space Administration REPORT NUMBER TM- 109924 Washington, DC 20546

! !. SUPPLEMENTARY NOTES

12a. DISTRIBUTION / AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE Unclassified / Unlimited Subject category - 82

13. ABSTRACT The six-month beta test of the NASA Access Mechanism (NAM) prototype was completed on June 30, 1993. This report documents the lessons learned from the use of this Graphical User Interface to NASA databases such as the NASA STI Database, outside databases, Internet resources, and peers in the NASA R&D community. Design decisions, such as the use of XWindows software, a client-server distributed architecture, and use of the NASA Science Internet, are explained. Users' reactions to the interface and suggestions for design changes are reported, as are the changes made by the software developers based on new technology for information discovery and retrieval. The lessons learned section also reports reactions from the public, both at demonstrations and in response to articles in the trade press and journals. Recommendations are included for future versions, such as a World Wide Web (WXVW) and Mosaic based interface to heterogeneous databases, and NAM-Lite, a version which allows customization to include utilities provided locally at NASA Centers.

4. SUBJECT TERMS 15. NUMBER OF PAGES databases, computer programs, information systems, prototypes, on-line 37 systems, architecture (computers), information retrieval 16. PRICE CODE A03

17. SECURITY CLASSIFICATION 18. SECURITY CLASSIHCATION 19. SECURITY CLASSIFICATION 20. LIMITATION OF ABSTRACT OF REPORT Unclassified OF THIS PAGE Unclassified OF ABSTRACT Unclassified Unlimited

Available from NASA Center for AeroSpace Information 800 Elkridge Landing Road Linthicum Heights, MD 21090-2934 (301) 621-0390