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Author(s) Gebhardt, Heidi L Title Communication

1. Bus DQDB High Speed Serial Bus HSSB In vehicle Communication Bus Advanced Mobile Phone Service Connectionless Network Protocol CLNP Transport Protocol 4 TP4 and Global System for Mobile Communications are all available from third parties OPNET models multiple client server applications email database file transfer etc peer to peer protocol delays server backlogs and transaction response time and throughputs It also models satellite systems and mobile communications nodes Some military system libraries are available for this product These are available through various Department of Defense agencies 3 Configuration Management The user is responsible for managing input and output files Separate probes will have separate output files However a rerun of a model will overwrite existing output files The user can graphically display the Network Node or Process levels of the model Each layer provides the user with a different degree of the model s detail 4 Cost OPNET Modeler is available commercially for 18 000 00 This includes all of the current commercial libraries and 90 days of maintenance and technical support Additional technical and upgrade support is available for 3 000 00 per year The university edition is available for 600 00 per year MIL 3 Inc offers a free one day training seminar They also have a three day OPNET Modeler course available in Washington DC for 1 500 00 Customized
2. California 93943 5101 Brei or Dan C Boger CC BO santa ne een Naval Postgraduate School Monterey California 93943 5101 Professor Paul H Moose CC Mo 0 oo ccc c ccc cc cece cvccvccccccccsccsecedesececvcss Naval Postgraduate School Monterey California 93943 5101 a Heiler Gebhardt Bere ee en innen PO Box 265 31 Four Wheel Drive Road Warren Pennsylvania 16365 61 CAPT Jay Kistler IA 22 Chief of Naval Operations 2000 Navy Pentagon OPNAV N6M Washington D C 20350 2000 62
3. Price Commercial 18 000 00 48 500 00 695 00 23 500 00 40 800 00 University 600 00 3000 00 350 00 500 00 500 00 Accessibili 3 Completeness 4 Management Cost 2 HP UX SGI AIX Solaris 43 OPNET COMNET II EXTEND WORKBENCH G2 MODELER Methods Reduction Documentation 4 _3 3 4 3 Ease Of Use 2 Desigr Extendibili 5 Of Results Fideli 5 Flexibili 4 Tateroperability 4 Miscellaneous 2 Environment Support Reliabili 5 Securi 3 Software 4 Tutorial per User Interface 4 Validation 5 Verification 5 Non Weighted 106 87 100 97 95 Totals Table 7 1 Comparison of Products C THE GRAND SOLUTION A quick total suggests that OPNET is the best overall software product However the criteria must be weighted when selecting a specific software product for the user s needs By weighting each evaluation criterion a priority for the characteristics required for a mission is established These weights may differ for each distinct task An organization should give serious consideration to the weights based on their generic usage of the product unless the organization can afford to purchase more than one product This will provide the organization with a product that may not be the best for every instance but will be the best for the organization s overall usage An example a unit is looking for a software product that can model experimental architectures and systems in addition to
4. The network topology can be created via drag and drop icons or with menu options Once the topology is established parameters may be altered by double clicking on the items A parameter window will appear with drop down menus to assist the user The verify option provides a detailed list of all errors present in the network topology or basic flow 20 The user may alter the run time parameters clock speed run iterations animation event trace through a simple menu Post analysis support allows the user to easily browse the reports and statistics 24 Validation The simulating of existing networks where measurement data is available produced results consistent with the real data COMNET II provides the user with a basic to intermediate analysis of the network and its interfaces This is dependent on the parameters and events established by the user 25 Verification Upon completion of the model the product does a quick verification of the network connections The tool seemed to function as described in the documentation Instructions detailed in the tutorial produced the desired results C CONCLUSIONS COMNET IL is a simple straightforward comprehensive network planning tool User training is easy and icon based network designing allows for quick construction and reconfiguration COMNET II provides a method for analyzing and optimizing computer based networks 21 IV EXTEND A INTRODUCTION Extend de
5. internally via tables External interfaces include C and C programs and Objectbench files The users must establish the link or interface between Workbench and the external functions 6 Data Reduction Workbench provides immediate access to statistics gathered during a simulation run The user can select global or specific statistics to be gathered The standard statistics that Workbench gathers are inter arrival lifetime population q population q response quantity response and utilization Users can also create user defined collect statements in C language to accumulate additional continuous or discrete statistics not ordinarily collected by Workbench Workbench includes these probability distributions empirical erlang exponential gamma hyper exponential normal triangular uniform binomial geometric I empirial I uniform and poisson ie Documentation Workbench s documentation is quite extensive The Quick Start Manual provides a basic overview of the most commonly used features and includes an example or mini tutorial on creating compiling and animating a simple model Creating Models Simulating Models SES sim Language Reference Technical Reference Query Interpreter and Language Reference Cosim Reference and an Installation Manual are also included in the Workbench documentation No design specifications were available 8 Ease Of Use The basic features of Workbench are fairly easy to learn and u
6. provides a basic overview and helps the user to locate the cause of the fault Errors are listed by line of code which is immediately displayed for the user Various options are available within the animation probe to enhance the user s 11 troubleshooting capabilities Assistance is available by phone email and through the world wide web 23 User Interface The user interface is a mixture of windows menus icons and text editors A window listing the current functions of the mouse buttons is provided at the bottom of the screen A command window informs the user of the current status of the screen Multiple levels can be open at the same time and a recirculate button permits the user to move freely from level to level The numerous menus can be confusing to novice users 24 Validation The tool is capable of providing a very detailed solution The simulation of existing systems where measurement data was available produced results consistent with the real data 25 Verification The tool seemed to function as described in the documentation Instructions detailed in the tutorial produced the desired results C CONCLUSIONS OPNET Modeler while not for the beginner is a comprehensive tool It provides the user with the ability to model at the state and process level This provides a greater flexibility in the modeling of new technologies OPNET is a sophisticated program for modeling and simulating communication system
7. quick high to intermediate level network modeling with familiar built in icons Extend developed by Imagine That Inc is very user friendly It does not contain network icons but the user can build them The product is flexible and can be used to model more than just networks computers and communication equipment Workbench created by Scientific and Engineering Software Inc permits users to access the model s code Network icons are not included but can be created by the user or purchased for an additional cost Access to the model s code and debugging the model are all completed in a language similar to C These can be difficult for a non programmer G2 by Gensym Corporation provides a completely object oriented modeling environment The documentation is very confusing Programming is easy for non programmers It is completed in a structured natural language similar to the human language 49 A user s needs and modeling and programming capabilities should be evaluated prior to choosing a software product A weighted criteria evaluation is recommended for selecting the correct software tool B APPLICATIONS WITHIN THE MILITARY The complex technology and the limited availability of troops and money provides an environment without the capability to fully test evaluate integrate and analyze new equipment Modulation simulators can be used to evaluate the integration of new equipment New equipment can be modeled tested and
8. reader with the knowledge to make an informed product selection based on the user s needs A matrix of the products and the evaluation criteria provides a quick overview of the analysis 14 SUBJECT TERMS COMNET II OPNET Modeler Workbench Extend G2 PAGES 16 PRICE CODE 20 LIMITATION OF 17 SECURITY CLASSIFICA TION OF REPORT ABSTRACT Unclassified UL NSN 7540 01 280 5500 Standard Form 298 Rev 2 89 Prescribed by ANSI Std 239 18 298 102 18 SECURITY CLASSIFI CATION OF THIS PAGE Unclassified 19 SECURITY CLASSIFICA TION OF ABSTRACT Unclassified Approved for public release distribution is unlimited COMMUNICATION MODULATION SIMULATORS AN ASSESSMENT Heidi L Gebhardt Captain United States Army B S Pennsylvania State University 1988 Submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE IN SYSTEM TECHNOLOGY Command Control and Communications from the NAVAL POSTGRADUATE SCHOOL June 1997 ANCS RAEG YE PE AS a G 753 a vito Y muni EY KNOX LIBRAR i LU N nn BS b SCHOOL p G ys 3 ws ABSTRACT The military drawdown and budget cutbacks have created a greater emphasis on shorter faster and cheaper ways to do the mission Modulation simulators have become a critical component in the evaluation and testing and integration of new network communications and command and control technologies and applic
9. terrain or frequency features Outages must be developed as part of the model Delays and blocks can simulate temporary and permanent outages Time delays probability distributions and triggers can be established to create and fix outages 16 Operational Environment Workbench is only available for UNIX platforms and thus are not very portable The platforms are commercially available 17 Post Analysis Support Workbench provides textual reports and machine readable output The reports can be displayed on the screen or printed The reports consist of a cover page two optional user generated output sections a report header a detailed statistical report an optional node summary statistical report and an ending banner The machine readable output can be post processed using most commercial spreadsheets or word processors The user can also print the graphical representation of the model Available only on SUN platforms SES graph is a small easy to use graph program It is a front end for a program called grafit R created by Graphicus Inc Kirkland Washington SES 1994 1995 pp A 1 SES graph enables the user to display and plot statistical data produced during the model s run These graphs can be displayed in bar charts pie charts line charts spline charts or a step function chart 33 18 Reliability The product executes in its own run time environment Debugging features are included 19 Security Workben
10. 2 TROUBLESHOOTING ASSISTANCE e Is animation available e Ability to view code Can you see inside the model 54 e 1 800 help lines e Frequent problems list lessons learned 23 USER INTERFACE e Type Windows C programming UNIX programming etc e Quality e Effectiveness 24 VALIDATION e Degree of accuracy e Variable quick answer intermediate answer detailed answer 25 VERIFICATION e Of tool design and functions How do we know it works 55 LIST OF REFERENCES CACI Products Company COMNET III Network Simulation Tool http www caciasl com comnet html April 1997 CACI Products Company COMNET III User s Manual Planning for Network Managers CACI 1995 Gensym G2 Reference Manual Version 4 0 Gensym Corporation 1995 Gensym Gensym http www gensym com products g2realtime html May 1997 Imagine That Inc Extend Performance Modeling for Decision Support Imagine That ne 1995 MIL 3 Inc Corporate Background Prentice Hall 1987 MIL 3 Inc OPNET Modeler Users Manual MIL 3 Inc 1989 1996 Pressman R S Software Engineering A Practitioner s Approach McGraw Hill Inc 1992 SES SES Workbench Simulating Models Scientific and Engineering Software Incorporation 1994 1995 Sullivan J E A Computer Network Simulation Tutorial For COMNET IT Naval Postgraduate School 1996 57 BIBLIOGRAPHY Advanced Research Center Computer Software and Communicatio
11. 5 Flexibili 5 4 20 Interoperability 2 4 8 Miscellaneous 1 2 2 Operational 3 5 15 3 5 15 3 5 15 3 5 15 Environment 45 OPNET COMNET II EXTEND WORKBENCH G2 MODELER Support l Reliabili 345 15 3 5 15 Securi 1 3 3 Ber Software 5 4 20 Tutorial Assistance User Interface 5 4 20 Validation S56 15 Verification Seal Non Weighted 369 306 378 348 344 Totals Table 7 2 Example Weighted Comparison of Products D OVERALL COMPARISON Each of the five products analyzed in this thesis has its own special characteristics and capabilities Why select one over the other The functions and capabilities vary making some products more preferable for different applications and scenarios CACT s COMNET II is the best choice for modeling a WAN or LAN COMNET IM provides all the familiar computer network icons in a user friendly environment to enable the user to quickly model and analyze a computer network COMNET IM however does not model communication or information systems Nor does COMNET IH model the innards of a computer MIL 3 developed OPNET Modeler which can model computers communication and information systems from the network through the process and state levels Numerous libraries are available to assist the modeler OPNET s primary disadvantage is its fixed run speed This can cause extensive time delays during a simulation run of a detailed model SES Workbench like OPNET can be used to model communication co
12. 8 A 29 A NO EEEISDEeE EEREEENRIUEEEEERERREREEERERFRRERNE GE SE0R 2 Eur 7 SS MENTERITERTR ere anne ee 23 NA EERREREEEEEEEEEREEEEURRREFBEELTEER Cr gt gt A e254 AG dde aA ced oo sededss suas duudsedcerdiussseennsccccocsseeeesesunsbuubavesaels 37 A INTRODUC TE 6 10S er E 37 ASS ANA a E nen 37 u GONGSO S a a E CEERREREEEEEEEEEEEEEEEEREHERHREEERREREA 42 SOLL ANNL SIS oss a EE 43 A AO O E A 43 A 43 A GIRANDO O O NEE III EEEEREREEEEEEBERDRRELTERTETTSSPREFERRERERESE 44 PERA CLG 3 7285 0S J Seno essers teneate kan eias 46 AU CORCLUSKONS a a E een 49 Aa UMIAR o o a E A 49 PESE EICATIONS WITHIN THE MILITARY 200000000000000000 00000 50 OS EC ONMMENDED FUTURE STUDIES c00cssssensenecssicccessaseoscosssevscssoses 50 APPENDIX DEFINITIONS OF ASSESSMENT MEASURES c ooocoocccccccocoocccnnocacnccnonnnns 51 Lod OI BERN a a E nn IA 57 vii BIBLIOGRAPHY oee INITIAL DISTRIBUTION LIST vo m aa a n nm nm n 2 9 eo oe 2 2 2 VE HH HH HHHTHH TH HH HH HH ET TR HH HH HOHES HT EHE HE SE SOHSSSHSSSHSHESHSHSSSHSHSHSSHSHSHSSHSSSHSSHSSHSSSHSSSSSSSHSSHSSSSSHSSSSSHSSSSSHSSSSHSSSHSSSSSCSSeeeeeeeeeeeeesd Vill ACKNOWLEDGMENT The author would like to thank Professor John Osmundson for his support guidance and patience during the preparation of this thesis EXECUTIVE SUMMARY The drawdown and budget cutbacks have created a situation where the military must use alternate means to evaluate existing
13. Extendibility The program itself cannot be modified or extended The source code is not provided to the user COMNET II does provide the user with a high level simple program interface The programming is similar to Basic It provides greater flexibility to the user Counters and triggers can be established to initiate follow on events An example would be when the utilization of a link is greater than 60 switch to an alternate link 11 Extensibility Of Results COMNET II provides the user with two primary methods for evaluating an emerging architecture First with the basic high level programming option which can be used to set counters and triggers to evaluate the results of an event second through the 17 use of transit nets Transit nets provide a more detailed option for modeling transport protocols It enables the user to create a protocol like frame relay via an ATM link COMNET Ill does not specifically model data channels or software applications 12 Fidelity The tool reliably provides results consistent with the input parameters COMNET Baseliner an add on feature enables the user to model existing networks with realistic external data The detail of the model can only be slightly varied 13 Flexibility Nodes can be set up to start stop or model a delay during the execution Parameters can be easily altered by double clicking on the items icon 14 Interoperability COMNET Baseliner an add on feature enables th
14. Inc Sun SPARC PCs Windows PCs Windows Sun Micro 3 1 NT and stations IBM Windows 95 HP Macintosh SGI Windows Windows 95 UNIX DEC HP UX SGI AIX Solaris 600 00 3000 00 350 00 500 00 NT Xii G2 Intelligent Real Time Systems Gensym Corp Digital IBM HP Sun Micro stations PC s Windows NT and Windows 95 40 800 00 500 00 3 4 5 AJ N MINH IRL U OPNET COMNET HI EXTEND WORKBENCH G2 MODELER Assistance User Interface 7 Validation 5 Verification 5 5 Non Weighted 106 100 95 Totals Each of the five products analyzed has special characteristics and qualities The products functions and capabilities vary making each product perfect for a different scenario CACT s COMNET II is the best choice for modeling a wide area network or local area network COMNET II provides all the familiar computer network icons in a user friendly environment to enable the user to quickly model and analyze a computer network COMNET II however does not model communication or information systems Nor does COMNET III model the innards of a computer MIL 3 Inc developed OPNET Modeler which can model computers communication and information systems from the network through the process and state levels Numerous libraries are available to assist the modeler OPNET s primary disadvantage is its fixed run speed This can cause extensive time delays during a simulation run of a detailed mo
15. LANs are easily modeled through use of subnets and WAN cloud icons These provide the user with various views of the network hierarchy WAN clouds can be used to model frame relay cell relay ATM and packet switching X 25 Inter machine communications can be modeled if the user knows the parameters of the interface COMNET II does not model communication system networks COMNET II currently does not model any military specific equipment 3 Configuration Management CACI Products Company began developing simulations over 35 years ago COMNET II is only a few years old but is widely used throughout the civilian community COMNET II is currently on Version 1 3 It is configured as a proprietary execution environment 14 Users are responsible for managing traffic input and data output Output files will be overwritten during a re run of a modified model The entire network is displayed for the user Details of individual nodes can be accessed and parts of the network can be hidden via COMNET WAN Clouds and Transit Nets COMNET WAN Clouds and Transit Nets are icons which represent portions of the entire network to reduce the clutter on the display 4 Cost COMNET IT is 48 500 00 for the commercial version 2 000 00 for a single user university edition and 3 000 00 for a university department edition Training costs and maintenance and upgrade costs for the first year are included Afterwards the yearly commercial maintenance
16. NPS ARCHIVE 1997 01 GEBHARDT H NAVAL POSTGRADUATE SCHOOL MONTEREY CALIFORNIA THESIS COMMUNICATION MODULATION SIMULATORS AN ASSESSMENT by Heidi L Gebhardt June 1997 Principal Advisor John Osmundson Associate Advisor Donald van Z Wadsworth Thesis G25733 Approved for public release distribution is unlimited e DUDLEY KNOX LIBRARY qe UL RO STGRADUATE SCHOOL Bio Palicy Ch Ey 1 31 REPORT DOCUMENTATION PAGE Form Approved OMB No 0704 0188 Public reporting burden for this collection of informauon is estimated to average hour per response including the ume for reviewing instruction searching existing data sources gathering and maintaining the data needed and completing and reviewing the collection of information Send comments regarding this burden estimate or any other aspect of this collection of information including suggestions for reducing this burden to Washington Headquarters Services Directorate for Information Operations and Repons 1215 Jefferson Davis Highway Suite 1204 Arlington VA 22202 4302 and to the Office of Management and Budget Paperwork Reduction Project 0704 0188 Washington DC 20503 AGENCY USE ONLY Leave blank 2 REPORT DATE REPORT TYPE AND DATES COVERED June 1997 Master s Thesis TITLE AND SUBTITLE COMMUNICATION MODULATION 5 FUNDING NUMBERS SIMULATORS AN ASSESSMENT AUTHOR S Gebhardt Heidi L PERFORMING ORGANIZATION NAME S AND ADDRE
17. OTS products This thesis evaluates five of the current commercial modulation simulators OPNET Modeler 3 0 by MIL 3 Inc COMNET III by CACI Products Company Extend by Imagine That Inc Workbench by Scientific and Engineering Software Inc and G2 by Gensym Corporation Each product is evaluated against twenty five assessment criteria See Appendix A score of 1 to 5 5 is the best will be assessed for each criteria The objective is to provide the reader with the information required to intelligently select the most useful modulation simulator for a specific mission The software product chapters Chapter Il through Chapter VI include an overview of each product and a detailed evaluation of the product based on each of the criteria and sub criteria Chapter VII is the analysis comparison chapter which summarizes the results and provides the reader with a basis for making an informed selection Examples are provided in Chapter VII to assist the reader with how to effectively select the correct software product Evaluations are based on a hands on utilization of each product tutorials world wide web and user demonstrations all available documentation and interviews with users sales representatives and technical support personnel C PRODUCT SELECTION The software products selected were based upon availability to the author current or proposed usage in the military and experienced users recommendations Many of the products can be us
18. PNET provides a restricted access security Three types of users can be established A bas c user can run a model but can not view the model in OPNET Editor An inspector has basic user permissions plus the ability to inspect the model with certain interface procedures A full user has complete access to the model and can edit the model via the OPNET Editor 20 Software OPNET Modeler is an object oriented program introduced by MIL 3 Inc in 1987 The source software is unavailable to the user The user can program entrance and exit criteria for states with Proto C Proto C is very similar to the C language The user is provided access to some programming code in the event of an error This is only to assist the user in troubleshooting the fault 21 Training Tutorial The tutorial is comprehensive and informative It takes the user step by step through the menus and model development of various types of networks Some of the menus were incorrectly labeled in the tutorial but the correct menu was pictured and the correct steps to reach the menu were given The tutorial provides the user with a intermediate knowledge of the product Someone with little or no modeling background would have a difficult experience using the product after the tutorial It is written for a semi experienced modeler programmer 22 Troubleshooting Assistance Troubleshooting is difficult All troubleshooting is oriented to the programmer The documentation
19. SS ES 8 PERFORMING Naval Postgraduate School ORGANIZATION Monterey CA 93943 5000 REPORT NUMBER 9 SPONSORING MONITORING AGENCY NAME S AND ADDRESS ES 10 SPONSORING MONITORING AGENCY REPORT NUMBER 11 SUPPLEMENTARY NOTES The views expressed in this thesis are those of the author and do not reflect the official policy or position of the Department of Defense or the U S Government 12a DISTRIBUTION AVAILABILITY STATEMENT 12b DISTRIBUTION CODE Approved for public release distribution is unlimited 13 ABSTRACT maximum 200 words The military drawdown and budget cutbacks have created a greater emphas s on shorter faster and cheaper ways to do the mission Modulation simulators have become a critical component n the evaluation and testing and integration of new network communications and command and control technologies and applications This thesis evaluates five current commercial off the shelf products OPNET Modeler by MIL 3 Inc COMNET II designed by CACI Products Company Extend by Imagine That Inc Workbench created by Scientific Engineering Software Inc and G2 from the Gensym Corporation Each of the products is evaluated using twenty five primary evaluation criteria The evaluations include current costs completeness user interface and post analysis support methods and they describe the basic features and distinctive characteristics of each product The capabilities of the products are compared providing the
20. a triggers probability distributions or timed events These can be programmed to be permanent or merely timed events OPNET can also model atmospheric propagation among satellite links and airborne communication systems 16 Operational Environment The portability of the product is dependent on the computer platform All platforms available are COTs 17 Post Analysis Support OPNET Modeler provides a wide variety of reports and graphs The data collected is user selected via probes Probes are established to collect data on various points in the network Multiple probes can be utilized during the same run Probe types are node statistics link statistics global statistics and simulation attributes The user can view the probe results with multiple or single output vectors These vectors are selected by the user and displayed as traces or graphs OPNET Modeler s analysis tool supports a variety of calculations histograms probability distribution functions cumulative distribution functions and confidence intervals Additionally the user can create mathematical filters to help evaluate the data This program enables the user to export the results with encapsulated Postscript files or TIFF files to desktop publishing packages 10 18 Reliability OPNET Modeler is a Proto C based product with icon and menu user interfaces It executes in its own run time environment Repeat runs produce consistent results 19 Security O
21. and easily obtainable to users Portability depends on the platform the software is installed on 17 Post Analysis Support COMNET III provides a wide variety of reports Each of these is available for viewing immediately after the run execution Reports must be turned on by the user for the data to be collected The following reports are available within COMNET M CACTI 1997 COMNET UI Features List 18 Node Reports Processor and disk utilization Received message counts Session level Call counts Call level Buffers by node Buffers by port Link Reports Channel utilization Utilization by application Utilization by protocol Frame Size Collision Statistics Token ring statistics Session level Call counts Call level WAN Cloud Reports Message and Response Source Reports Message delay Message delivered delay Packet delay Cell Source Reports Blocked call counts Disconnected call counts Preempted call counts Transport Command Reports Message delay Packet delay Session Source Reports Message delay Message delivered delay Packet delay Setup delay Session Length Setup counts Transport Layer Snapshot Reports Node reports Link reports Cloud virtual circuits Statistics file for export to other analysis Real time plots Post processed plots Percentiles Raw data plot file Reliability The product is coded primarily in a high level icon drag and drop language lt executes in its own run time env
22. and emerging communications computer and information systems It is no longer feasible to build computer communications and information systems solely for testing and evaluation purposes Money equipment soldiers and time are not available to disconnect existing information systems for testing and evaluation It is standard practice to utilize software simulation including hardware and man in the loop to expedite development testing and evaluation of computer communication and information systems This thesis examines the current state of the art modulation simulators so called because signal modulation is required to communicate information Modulation simulation is a computerized method for modeling a current or future communications computer or command and control system Modulation simulators assist the user in designing evaluating testing and reconfiguring a system It is much less expensive to model a new system with a modulation simulator than to physically build a demonstration example Modulation simulators allow for parameter variation protocol variation load testing and reconfiguration all within the computer Modulation simulators allow users to examine emerging system s interfaces with current military commercial and joint networks and they provide a method for testing futuristic technologies Additionally they enable the user to evaluate network performance to test the effects of system outages to stress the syste
23. and historical data 18 Reliability The product executes in its own run time environment Results are consistent with the inputted model 19 Security G2 provides network security features These features include connect read write execute and inform Connect prohibits or enables other users from accessing a KB Read and write prohibit or enable other users from reading or writing variable values The execute command deals with remote procedure calls and the inform command prohibits or enables other users from sending messages to the operator 20 Software G2 s structured natural language provides the modeler with a user friendly program interface The modeler can use ordinary human language statements to input specific commands for the model to execute G2 s language and modeling environment are object oriented 21 Training Tutorial G2 offers numerous training courses Introduction G2 Part I G2 Part II and many classes for supporting products Courses provide a wide variety of information on how to use G2 The combine syllabus for the Introduction and G2 Parts I and I indicates that upon completion of the training the user will have an intermediate knowledge of the product No tutorial is available Some demonstration KBs are included 22 Troubleshooting Assistance G2 has been rated number one in customer support by Control Magazine for the last two years Gensym 1997 pp Services Engineers are availa
24. and upgrade fee is 5 100 00 and the university fee is 500 00 Additional packages COMNET Baseliner and the COMNET Advance Features Package are 9 000 00 each S Data Input Methods Users can create discrete data and continuous random variable data through tables The discrete data is based on inputs from the user and a step distribution The continuous data is based on a user selected probability distribution function COMNET II also features source objects Traffic Message Response and Session Traffic Source is used to model a single traffic command Message Source works with a transport command and models protocol control messages Response Sources generate replies or acknowledgments and Session Sources are for modeling multiple message bursts or virtual circuit routed messages Traffic and network topologies can be modeled through external sources TRAFLINK a CACI utility reads external traffic files and formats them for COMNET II usage Network topologies can be extracted from Network Management Systems Third party software Cabletron Spectrum topology files HP Open View topology files and IBM Net View 6000 topology files can extract an existing network s topology to be imported into COMNET CACI Products Company 1995 pp 210 15 6 Data Reduction COMNET II provides immediate graphs and reports A Report Menu allows the user to turn on and off various reports and statistics for specific items nodes links WAN cloud
25. ations This thesis evaluates five current commercial off the shelf products OPNET Modeler by MIL 3 Inc COMNET II designed by CACI Products Company s Extend by Imagine That Inc Workbench created by Scientific Engineering Software Inc and G2 from the Gensym Corporation Each of the products is evaluated using twenty five primary evaluation criteria The evaluations include current costs completeness user interface and post analysis support methods and they describe the basic features and distinctive characteristics of each product The capabilities of the products are compared providing the reader with the knowledge to make an informed product selection based on the user s needs A matrix of the products and the evaluation criteria provides a quick overview of the analysis TABLE OF CONTENTS IE O CS BOUIN oye een occ eee l A MILITARY AND MODULATION SIMULATORS conooococccccconncnccnonanioncononcnconononos l O 2 Es PRODUCT sles O A IN 2 EAT SES ee v5yea0cecceancdeacccnascendesieceentasseseeunsccissovevesesdscssdesovedeueosesetense gt A TONPITIES GIDACINC TENG NON 5 Ei ASS AMS A OI 5 D ON ALSO S e E E 12 O O II EEE neno ca ncadannnndoni nina nna nacos 13 ID AO 13 ESS BOSSE IAN ECG a UN 2 Se 2 RR nee ee 13 O A nee EEE ne 21 A O 23 A INTERNE LEN anyon E ENE 23 PE STAENTTERTTERTA oo conictocococicc nncononanoconconeccuasivicas nccccnenconcancionnicocarcadaci n 23 SING US EN Se ER EEE EINEEEERERRRRRRREREEEEREEETEREN 2
26. ble by telephone Monday through Friday to assist with installation product use problem diagnosis and configuration questions 41 G2 Help Link is a 24 hours a day seven days a week automated help service available through the G2 world wide web home page The Gensym Users Society GUS provides technical communications between Gensym customers and the Gensym Corporation Help services are also available through email Animation is not available 23 User Interface The G2 user interface is menu oriented The number of menus can be overwhelming to the beginning user Menus lead to construction of objects classes connections etc Once an item is created it is defined through a table Most table entries are prompted with a list of available options Some entries allow the user to provide input into the model For example variable and object names or the use of structured natural language to input exact specifications for an object 24 Validation Users can model to the depth desired The user must use correct object oriented analysis to properly define the system to be modeled 25 Verification The product functioned as described in the manuals Gensym Corporation has sold more than 7500 product licenses to over 500 organizations worldwide Gensym 1997 pp Company CONCLUSIONS G2 s based on object oriented analysis and design Object oriented analysis is based upon concepts that we first learned in kind
27. ch does not offer any security features 20 Software Workbench is based on the C language Workbench uses an object oriented environment The user can access and alter the code developed for the model 21 Training Tutorial Workbench training is available at SES Regional Sites Customized training can be requested for a cost to be conducted at the user s site Introductory and advance classes are available Workbench s documentation includes a basic tutorial It is a quick overview of the program s primary features 22 Troubleshooting Assistance Workbench has animation and trace capabilities The user can view the code by accessing the model s file SES offers assistance via a 1 800 telephone number email the world wide web and through regional sites Frequently asked questions are available through the world wide web to registered users 23 User Interface The user interface is graphic oriented The user through menus icons and arcs or connection tools creates a graphic picture of the model The flow of the menus can be confusing to the novice user The user can modify the parameters of the nodes and can add C programming to augment the simulation 24 Validation Workbench provides the user with the option of modeling to the small details or on a larger scale Models programmed via code will depend on the users modeling ability for validity 34 25 Verification No verification features were identifie
28. communication and computer networks The unit has no UNIX machines mostly PCs and a few Macintoshes The operators are proficient in C Language but troubleshooting assistance and user interface are considered key for the experimental design of the system Frequency and terrain have no bearing on the systems to be modeled Minimizing cost is very important to the unit The unit may establish the following weights Completeness 1 Cost 5 Experimental Design 5 Extendibility 4 Miscellaneous 1 Security 1 Software 5 Troubleshooting Assistance 5 User Interface 5 and all other criteria may be a 3 Each weight is then multiplied by the product s score to produce a weighted score The weighted scores are totaled The product with the highest weighted score is the best modulation simulator based on the current priorities In this example that would be Extend Table 7 2 depicts the comparison example with weighted scores OPNET COMNETHI EXTEND WORKBENCH G2 MODELER General Use 5 4 20 Platform 4 4 16 Accessibili 3 3 9 Completeness 1 4 4 Configuration Bt 15 3 4 12 3 4 12 B75 15 375 15 Management Cost 5 4 20 5 5 25 5 3 15 5 2 10 Methods Reduction Documentation 3 4 12 3 4 12 3 3 9 Ease Of Use 3 4 12 3 2 6 Experimental 5 4 20 IZ 10 573 25 Sel SS Design Extendibili A 4 16 4 4 16 4 5 20 4 5 20 Extensibility 3 5 15 3 4 12 3 4 12 3 4 12 Of Results Fideli 3 5 1
29. d The product seems to function as described in the manual E CONCLUSIONS The basic commands for Workbench are easy to learn Workbench requires the user to be a proficient modeler The user must be able to understand the basic functions of the system they are modeling Workbench also places heavy emphasis on understanding programming Workbench is a good tool however it is not designed for the beginner 35 A INTRODUCTION G2 from the Gensym Corporation is designed for developing intelligent knowledge based real time applications G2 is typically utilized for complex situations that require monitoring diagnosis and alarm handling scheduling and logistics supervisory and advanced control process design simulation and re engineering intelligent network management and decision support for enterprise wide operations Gensym 1995 pp 4 Each intelligent application developed or modeled is known as a knowledge base KB KBs are developed in a graphical and menu oriented environment using Object Oriented Modeling Gensym Corporation uses Object Oriented Modeling as the bases of the G2 product B ASSESSMENT CRITERIA 1 Accessibility G2 can be installed on UNIX VMS Windows 95 and Windows NT platforms These include Digital Equipment Corporation Hewlett Packard Sun SPARC stations Silicon Graphics and IBM Reduced Instruction Set Computers G2 requires 30 MB of hard disk space and 48 MB of RAM 2 Completene
30. del SES Workbench like OPNET can be used to model communication computer and information systems In addition Workbench can be used to model numerous other types of systems to include queues electric flow water pollution etc The ability to model more than just communication computer and information systems provide an added flexibility to the modeler Extend developed by Imagine That Inc is similar in its capabilities to Workbench in that it can also model any type of system Extend however provides a more user friendly environment for the modeler Besides the documentation s ease of use the menu setup has a more logical flow Workbench through the use of sub xiii modules can model to a smaller level of detail than Extend and Workbench can handle larger sized models G2 also similar to Workbench in its system modeling capabilities is in a class by itself G2 utilizes an object oriented modeling environment with a structured natural language This product is a great selection for a beginner or non programmer Object oriented modeling enables the modeler to design the level of fidelity and complexity to be modeled G2 includes a wide range of knowledge bases or libraries though the labeling is puzzling G2 object oriented modeling is not an easy product modeling method to learn In making a selection it also is essential to look at the capabilities and characteristics of the modeler Programming skills may influenc
31. e developed with various degrees of detail 13 Flexibility Nodes can be moved both on and off line The user can establish time delays triggers or interactive inputs to initiate the move or outage 14 Interoperability G2 provides networking and interfacing through Telewindows G2 to G2 Interface G2 Standard Interface GSI and G2 File Interface GFD Telewindows allows more than one user to access or remote view a running G2 process G2 to G2 Interface lets two or more G2 process to connect to share data GSTis a toolkit for developing bridges between G2 and external systems GFI allows G2 to read and write external data files 15 Miscellaneous Outages can be simulated with time delays triggers or interactive input by the operator Frequency and terrain options are not available with G2 16 Operational Environment This product is available for UNIX VMS and Windows platforms All these systems are COTs and easily obtainable to users Portability depends on the platform the software is installed on 17 Post Analysis Support G2 features include readout tables dials meters freeform tables charts graphs and trend charts Readout tables dials and meters depict changing values during a simulation run Freeform tables are similar to spreadsheets Charts plot numerical data 40 series Charts include data points bar charts and column charts Graphs are being replaced by trend charts Trend charts plot times series
32. e devices e Includes or is capable of modeling Intra and Inter machine communications e Includes or is capable of modeling military communication devices 3 CONFIGURATION MANAGEMENT e Maturity of software e User view of the model 4 COST e Military acquisition prices What extras are included e Maintenance costs e Training costs e Upgrade costs 5 DATA INPUT METHODS e Internal Methods e External Methods 6 DATA REDUCTION e How quickly 51 e What methods Poisson Wiebull etc 7 DOCUMENTATION e Requirements specification e Design document e Conceptual model document e Tutorial e User s Manual 8 EASE OF USE e Support for computer network modeling e Support for software modeling pre analysis sizing communications functional flow data flow CPU loading machine instruction specification etc e Support for data channeling modeling e Support for communications traffic modeling e Ease of learning e Manuals readily available and easy to understand e Setup time e Run time Can it be varied Typical run duration 9 EXPERIMENTAL DESIGN e Supports Monte Carlo e Supports algorithms e Iterative runs 10 EXTENDIBILITY e Can tool be readily modified e Design or programmatic e What language 11 EXTENSIBILITY OF RESULTS a2 e Alternative computer architectures Extension to hypothetical architectures Extension to architectures that may be performance tested Extension to architecture that are not available for test
33. e the product selection All five of the products are icon and menu oriented COMNET II provides the smallest programming interface and G2 has an easy to learn structured natural language OPNET Extend and Workbench each use a modified version of the C language Workbench presents the user with the largest interface with the model s code and provides the user with the most programming opportunities The user must take into consideration the various characteristics of the system to be modeled and the capabilities of the modeler This combination must be compared to the analysis of the products to correctly select the proper software modulation simulator for the mission X1V L INTRODUCTION A MILITARY AND MODULATION SIMULATORS It is standard practice to utilize software simulation including hardware and man in the loop to expedite development testing and evaluation of computer communication and information systems This thesis examines the current state of the art modulation simulators so called because signal modulation is required to communicate information Modulation simulation is a computerized method for modeling a current or future communications computer or command and control system Modulation simulators assist the user in designing evaluating testing and reconfiguring a system It is much less expensive to model a new system with a modulation simulator than to physically build a demonstration example Modulation si
34. e user to model existing topologies and use realistic traffic files Actually topology data can be taken via a Network Management System like HP Open View Network General Cabletron Spectrum IBM NetView for AIX and Castlerock SNMP and imported in COMNET Network traffic data can be gathered from Network General Distributed Sniffer System Frontier Software NETscout HP NetMetrix CompuWare EcoNET and 3COM LANsentry This data can then be imported into COMNET II via COMNET Baseliner This importing capability provides the user with the ability to model a current network and real data to run on it This model can then be tested to find any network problems evaluated for interfaces with new equipment tweaked to find the peak performance design etc A small amount of traffic gathered can be emulated to create a large database of realistic data This prevents the user from having to gather hours of real data 15 Miscellaneous Outages can be caused or enabled through parameter settings and or by establishing triggers and counters Outages can be for a predefined time simulating a nodes movement for a random time simulating a maintenance outage or permanently to simulate equipment destruction 18 Frequency and terrain options are not available with COMNET IL 16 Operational Environment This product is available for Windows 95 Windows NT UNIX stations SGI AIX Solaris Dec and HP UX systems All these systems are COTs
35. ed to model a wide range of systems This thesis concentrates on simulating communication computer and information networks This includes computer Local Area Networks LANs and Wide Area Networks WANs current military communication systems Mobile Subscriber Equipment Digital Group Multiplexing Equipment SINCGARS etc and message switching networks Additionally the thesis examines the software product s interface capabilities for modeling joint and emerging technologies II OPNET MODELER A INTRODUCTION OPNET Modeler by MIL 3 Inc is a computer aided engineering system for the design simulation and analysis of communication networks computer systems applications and distributed systems OPNET was introduced by MIL 3 Inc in 1987 Over 500 organizations both civilian and Department of Defense are currently using OPNET MIL 3 1987 OPNET Modeler has a detailed object oriented environment It utilizes a windows user interface with icons drop down menus and text editors for inputting the network OPNET provides the user with the flexibility to model top down bottom up or middle out OPNET provides the user with the ability to model from the Wide Area Network WAN down through the process and state level The process and state level is used to model the actions changes functions and conditions of the basic components of a model Various degrees of modeling provides the user with the added flexibility for modeli
36. end will verify the basics of the code during compilation The tool seemed to function as described in the documentation Instructions detailed in the tutorial produced the desired results C CONCLUSIONS The program Extend is not difficult to learn The user must be able to model the basic functions and flows of each element and combine them to build the model Due to Extend s purpose of modeling real life processing in a wide variety of areas many of its features are generic and not communication and computer specific This does not restrict the program s ability to model communication and computer networks but instead expands the user s modeling options 28 V WORKBENCH A INTRODUCTION Workbench developed by Scientific and Engineering Software Inc SES is a general purpose modulation and simulation tool Workbench is a collection of software tools used to design and evaluate sophisticated systems of various types It s major components are SES design a graphical editor SES sim a translation and simulation module and SES scope an animated simulator Workbench is an object oriented product Models are built with a top down construction beginning with the catalog level then the module and sub module levels Workbench is designed to model the essential characteristics of a system while ignoring the unimportant details It focuses on the high ievel system architectural issues B ASSESSMENT CRITERIA 1 Access
37. environment 19 Security No security features are available 20 Software Imagine That Inc developed Extend in 1987 Extend is written in ModL a C based language The user creates models by connecting building blocks to simulate the basic functions and flows of the system 21 Training Tutorial Imagine That Inc does not offer any in house training courses There are some third party training courses available for a cost The first three chapters of the Extend users manual are a comprehensive tutorial They provide the user with a complete overview of Extend s major features 22 Troubleshooting Assistance Animation and event tracing are available to assist the user in network flow monitoring and troubleshooting Common error messages and their causes are listed in an appendix Extend provides phone email fax and world wide web technical assistance Free technical assistance is available to all users modeling with the latest Extend upgrade 2 23 User Interface The product is very user friendly Extend s user interface is through building blocks and menus The user can quickly and easily build a model by selecting building blocks from the menu of libraries and then connecting the blocks together 24 Validation Extend s degree of accuracy 1s based on the users design A properly designed model produces realistic results The user creates the model to the depth of answer required 25 Verification Ext
38. ergarten objects and attributes classes and members wholes and parts Pressman 1992 pp 239 The product while initially intimidating is a very powerful tool The structured natural language enables a non programmer to have the features and capabilities available to create a detailed model of a complex system 42 VII ANALYSIS A INTRODUCTION This section compares the five software products A rating of 1 to 5 has been established for each evaluation criteria based on the sub criteria contained in the Appendix 1 no sub criteria satisfied 2 less than half of the sub criteria satisfied 3 half of the sub criteria satisfied 4 more than half of the sub criteria satisfied 5 all of the sub criteria satisfied Additionally general usage vendor available platforms and the average price have been included B COMPARISON Table 7 1 shows a non weighted comparison of the software products OPNET COMNET II EXTEND WORKBENCH G2 MODELER General Comm Network Simulation System Level Intelligent Real Usage Networks Planning Tool Tool Simulation Time Systems Computer LAN WAN Tool Systems and Applications and Distributed Systems Compan Inc Platforms Sun SPARC PCs Windows PCs Windows Sun Micro Digital IBM 3 1 NT and stations IBM HP Sun SGI Windows Windows 95 Windows 95 HP Micro stations NT UNIX DEC Macintosh PC s Windows NT and Windows 95
39. est programming interface and G2 has an easy to learn structured natural language OPNET Extend and Workbench each use a modified version of the C language Workbench presents the user with the largest interface with the model s code and provides the user with the most programming opportunities 47 VIII CONCLUSIONS A SUMMARY Today s technological advances are nearly overwhelming Increasing bandwidths increasing data rates new protocols and more all lead to new equipment available for the military The increased usage of COTS products encourages units to upgrade and replace existing capabilities The software products analyzed in this thesis can provide the user with a method for evaluating new equipment prior to its purchase It also enables the user to optimize existing systems and networks and to evaluate what if situations Each product has individual characteristics which make it the best choice for a particular user in a specific situation This thesis evaluated five modulation simulator software products based on twenty five evaluation criteria OPNET Modeler by MIL 3 Inc provides built in familiar network icons It provides the user with limited access to the code The user can program entrance and exit criteria for low level states and processes Access to code and debugging is in Proto C This can be troublesome for a non programmer COMNET II from CACI Products Company is easy to learn It provides
40. f computers and communication equipment and save them for reuse The manuals provide guidance on the G2 functions and features but do not cover any Object Oriented Modeling Set up time is dependent on the detail of the model the related KBs available to build upon and the users ability to use object oriented analysis and design G2 has three options for running a simulation real time simulated time and as fast as possible The model and the inputs can be altered while the simulation is running 9 Experimental Design G2 does not offer any iterative run capabilities Object oriented modeling enables the user to create objects and attributes to model emerging systems 10 Extendibility G2 models can be altered on line or off line G2 uses a structured natural language similar to COBOL The language uses ordinary human statements so the user does not need to be a proficient programmer G2 s natural language also supports Japanese Korean and Russian A text editor is available for the user to input specific statements rules functions attributes etc 39 11 Extensibility Of Results G2 and Object Orient Modeling provide the user with a flexible environment capable of modeling virtually any computer or communication system the user can imagine The product is limited by the users ability to analyze and design a model 12 Fidelity The tool reliably provides results consistent with the input parameters Models can b
41. has cross platform capabilities between Windows and Macintosh Extend allows users to copy data from text entry fields and data tables into other applications Extend permits the user to create building blocks to communicate with scientific equipment and other hardware devices Extend also provides two methods for accessing code written in another language XCMD for Macintosh and DLL for Windows 15 Miscellaneous Outages can be caused or enabled through delays triggers and blocks Outages can be for a predefined time simulating a nodes movement for a random time simulating a maintenance outage or permanently to simulate equipment destruction Frequency and terrain options are not available with Extend 16 Operational Environment This product is available for Windows and Macintosh systems All of these systems are COTs and easily obtainable to users Desktop and notebook computers are both very portable 26 17 Post Analysis Support Extend has a wide variety of plotters available to display output Discrete Event DE Error Bars DE Multi Simulation DE Error Bars Fast Fourier Transform Input Output Multi Simulation Histogram Scatter Scatter 4 Strip and the Worm The user can also select blocks to record data from for a report These reports only display final simulation values 18 Reliability Repeated runs of models based on constant inputs produce the same results Extend executes in its own run time
42. ibility Workbench is available for the Sun IBM and Hewlett Packard UNIX platforms 2 Completeness Workbench consists of a variety of module and sub module building blocks icons These building blocks can be used to create models of current and future computers software and communications equipment The models are constructed by connecting the build blocks or nodes with arcs Workbench permits the user to create icons These icons must be based on a basic building block but can be stored in a library for future usage The basic building blocks or the icon palettes for Workbench are Resource Management Nodes service delay resource allocate release create destroy block and set Transaction Flow Nodes source sink fork join split loop interrupt resume and branch Sub Module Management Nodes enter call sub model and return and Miscellaneous Nodes user declaration and super The catalog level provides the user with these building blocks main module generic module remote module interface module object file cosim interface archive file user make rules remote catalog and a palette icon 29 Once a module is bui it can be archived for use in future models This enables the user to create a library of frequently used items Workbench includes a variety of queuing rules These include priority rules which allow no priority preemptive and non preemptive priorities The time rules include first come first served las
43. ing e Alternative data channels Extension to hypothetical architectures Extension to architectures that may be performance tested Extension to architecture that are not available for testing e Alternative software descriptions e Alternative communication requirements 12 FIDELITY e Tool provides sufficient fidelity to ensure output accuracy across the tool architecture 13 FLEXIBILITY e Can nodes move on line off line How implemented e How quickly reconfigure 14 INTEROPERABILITY e Known interface capabilities software hardware e Interfaces under development e Partial interfaces available just the scenario 15 MISCELLANEOUS e Terrain ITs it available Can equipment be tied to terrain e Frequency Management capabilities e Outages Planned unplanned outages How implemented e Additional features 16 OPERATIONAL ENVIRONMENT 53 e System e Portable e Availability 17 POST ANALYSIS SUPPORT e Reports Variety e How quickly e Graphs Variety 18 RELIABILITY e Will it work every time producing the same results 19 SECURITY e Type of security Classified or User e Labeling e Passwords 20 SOFTWARE e Process maturity e Architecture e Complexity e Quality e Reliability e Sufficiency of testing e Modularity or Object Oriented Design e Maintainability 21 TRAINING TUTORIAL e Is it understandable User friendly e Is it complete e How proficient is user after training overview beginner master 2
44. integrated for less money and with less troops than physically fielding a piece of equipment Existing systems can be load tested reorganized and reconnected Outages and equipment losses can be simulated without the use of actual equipment and soldiers C RECOMMENDED FUTURE STUDIES The software tools evaluated in this thesis can be used to model virtually any computer communication or information system Future studies could include modeling and evaluating existing or emerging command and control or communications systems The growing inventory of modulation simulators has produced a concern for interface capabilities and limitations This can be expanded to include uses and interfaces with virtual reality simulators Additionally the Naval Postgraduate School is upgrading its existing internal computer network The current and future networks could be modeled and analyzed for shortcomings and improvements 50 APPENDIX DEFINITIONS OF ASSESSMENT MEASURES 1 ACCESSIBILITY Platforms supported e Conversion packages for switching to other platforms e Plans for support to any other platforms in the near future e PC version DOS or UNIX based 2 COMPLETENESS e Interactively models computers software and communications equipment e Includes or is capable of modeling current and new computer architectures e Includes or is capable of modeling current and new LANs WANs e Includes or is capable of modeling current or new mass storag
45. ironment Modeling errors may cause the experiment to suddenly terminate Diagnostic information is available 19 19 Security No security options are available 20 Software CACI Products Company has been a simulation leader for 35 years COMNET II Version 1 3 was fielded in December 1996 The source software code is unavailable to the user The product is a drag and drop icon and menu based environment It has a simple flow for network development CACI distributes minor releases throughout the year and major releases periodically Over 2000 various universities and companies are currently using COMNET II CACI 1997 pp A Quick Look at COMNET U COMNET Mis an object oriented software application 21 Training Tutorial CACI Products Company provides a free three day overview orientation training to new users Additionally the tutorial Sullivan 1996 is a great beginners manual Training is primarily at the beginner level COMNET II is not a difficult program to learn 22 Troubleshooting Assistance Animation and event tracing are available to assist the user in network flow monitoring and troubleshooting All valid users those having paid the yearly upgrade fee are provided with a Customer Support Hotline CACI for a cost has a Modeling Group to assist companies in developing a model for a network Assistance is available via email and the world wide web 23 User Interface The product is very user friendly
46. le user package Free one and one half day workshops are available at select regional sites G2 Part I and Part II training each a four and one half day course is available for 2 295 00 each 5 Data Input Methods G2 includes internal and external data source or data server features G2 s internal data servers are the G2 inference engine and the G2 simulator The G2 inference engine concludes or calculates an answer from specific formula objects The G2 simulator receives a value from a simulation formula External data server methods include data received from other G2 processes from GFI bridge applications and from GFI files See Interoperability sub section for more information 6 Data Reduction G2 does not offer any standard statistical features 38 de Documentation G2 provides a complex assortment of documentation The titles of the manuals are very misleading as to the content to a beginning user These manuals include G2 Reference Manual Upgrading Your Knowledge Bases G2 Systems Procedures Reference Manual Telewindows User s Guide and G2 GUIDE User s Guide G2 documentation is very complicated lt is oriented toward a proficient object oriented modeler G2 does not offer any tutorial Design and modeling documentation is not available 8 Ease Of Use G2 is not easy to learn It is entirely object oriented Existing KBs are not labeled well enough to know what they contain The user can create KBs o
47. llows the user to vary the run time and the step speed or clock speed The user can also vary the model while it is running online 9 Experimental Design Extend supports Monte Carlo and batch mode simulations Iterative runs can be conducted The plotters will only maintain the most recent four plots Extend s basic features enable the user to model emerging systerns 10 Extendibility Extend primarily uses icons or building blocks to construct models Extend s source code is the ModL language It is based on the language C Extend permits the user to create their own building blocks or modify existing ones The user can use scripting to design code for the model 25 11 Extensibility Of Results Extend allows the user to create building blocks These can be used to create virtually any communication or computer system Extend s extensibility is limited to the modeling and programming capabilities of the user 12 Fidelity The tool reliably provides results consistent with the input parameters and the model The user s ability to create building blocks could effect the behavior of the model Models can be developed with various degrees of detail 13 Flexibility Extend provides the ability to alter the model both on and off line The user can simulate the time lost for the movement of a node or for maintenance down time through the use of time delays blocks and triggers 14 Interoperability Extend
48. m under peak loading and to see how a network would react as equipment is moved simulating the flow of the battle or OOTW Operations Other Than War An analysis of five of the current commercial off the shelf software modulation simulator products provides the modeler with the information needed to make an informed product selection The five products OPNET Modeler developed by MIL 3 Inc COMNET II by CACI Products Company Extend created by Imagine That Inc Workbench by Scientific and Engineering Software Inc and G2 from the Gensym Corporation were evaluated against twenty five various criteria The following table xl provides a non weighted comparison evaluation of the products and some general overview information A rating of 1 the lowest to 5 the highest has been established for each evaluation criteria General Usage Vendor Platforms Price Commercial University Accessibili Completeness Configuration Management Cost Data Input Methods Data Reduction Documentation Ease Of Use Experimental Design Extendibili Extensibility Of Results Fideli Flexibili Interoperability Miscellaneous Operational Environment Post Analysis Support Reliabili Securi Software OPNET COMNET IH EXTEND WORKBENCH MODELER Comm Network Simulation System Level S mulation Tool Tool Networks Computer Planning Tool LAN WAN Systems and Applications and Distributed Systems Compan
49. mpany s world wide web page COMNET UI Tutorial Sullivan 1996 and telephone interviews with the sales and support offices B ASSESSMENT CRITERIA 1 Accessibility COMNET DI software currently is available for Windows 95 Windows NT all major UNIX computers Silicon Graphics Inc AIX Solaris Digital Equipment Corporation and Hewlett Packard UX The software package is 20 megabytes MB for 13 the UNIX or personal computer PC platforms It also requires 64 MB of remote access memory RAM for the UNIX and 32 MB for the PC 2 Completeness COMNET IH uses nodes and links as the primary model building devices Processor nodes model communication processing devices through time delays simulating the execution of software applications and the processing of packets Processor nodes simulate file read and writes and application runs through time delays and Wait For commands Router nodes model routers bridges switches hubs and other devices that have a common backplane for moving packets between port buffers Switch nodes model switches routers hubs and other communication devices that have insignificant packet moving delays The following links can be modeled by COMNET II CACI 1997 pp A Quick Look At COMNET II e Aloha e CSMA e FDDI e Priority FDDI e Polling e DAMA e Point to Point e Token Ring e CSMA CA e Token Passing e CSMA CD The Point to Point links include ISDN and SONET libraries WANs and
50. mputer and information systems In addition Workbench can be used to model numerous other types of systems to include queues electric flow water pollution etc The ability to model more than just communication computer and information systems provides an added flexibility to the modeler Extend developed by Imagine That Inc is similar in its capabilities to Workbench in that 1t can also model any type of system Extend however provides a more user friendly environment for the modeler Besides the documentation s ease of use the menu setup has a more logical flow Workbench through the use of sub modules can model to a smaller level of detail than Extend and Workbench can handle larger sized models G2 also similar to Workbench in 1ts system modeling capabilities 1s in a class by itself G2 utilizes an object oriented modeling environment with a structured natural language This product is a great selection for a beginner or non programmer Object oriented modeling enables the modeler to design the level of fidelity and complexity to be modeled G2 includes a wide range of knowledge bases or libraries though the labeling is puzzling G2 object oriented modeling is not an easy product modeling method to learn It is essential to look at the capabilities and characteristics of the modeler s Programming skills can influence the product selection All five of the products are icon and menu oriented COMNET II provides the small
51. mulators allow for parameter variation protocol variation load testing and reconfiguration all within the computer Modulation simulators allow users to examine emerging system s interfaces with current military commercial and joint networks and they provide a method for testing futuristic technologies Additionally they enable the user to evaluate network performance to test the effects of system outages to stress the system under peak loading and to see how a network would react as equipment is moved simulating the flow of the battle or OOTW Operations Other Than War Most organizations currently using modulation simulators are developmental testing and evaluation or acquisition oriented Some examples include Directorate of Combat Development Fort Gordon Georgia Joint Interoperability Testing Command Fort Huachuca Arizona and Defense Information Systems Agency D8 Arlington Virginia Modulation simulators could also be utilized by tactical operations staffs Networks designed for tactical exercises could be modeled tested and evaluated for trouble spots prior to deployment of personnel and equipment Networks could be tweaked for optimal reliability prior to installation This would save the military precious time and money B SCOPE The focus of this thesis is on commercial modulation simulators Budget cutbacks have reduced military software development resulting in most units turning to Commercial Off The Shelf C
52. nd run iterative trials Results are easy to view via the Browse option in the reports menu The network set up time is primarily restricted by the network knowledge of the user 16 The personnel at CACI Products Company were friendly and eager to assist The CACI world wide web page CACI 1997 pp COMNET Support provides helpful email addresses and phone numbers COMNET M and generic modeling questions can be answered via a customer hotline provided to valid users Additional modeling assistance is available at a cost from the CACI Modeling Group The product is very easy to learn The thesis tutorial developed by Jeffrey Sullivan Sullivan 1996 provides a quick overview of all of the basic COMNET HI features The run times of this product vary with the detail of the simulation The simple networks designs created using the tutorial executed in only a few minutes A detailed 10 000 node network with multiple events and detailed parameters would take much longer 9 Experimental Design The modeling tool provides the user with the ability to execute trials iteratively during a single run Additionally the automatic parameter feature enables the user to vary the parameters during the iterative executions This provides the user with a faster method for evaluating proposed network changes The user can modify existing parameters to examine alternate computer networks but COMNET can not model communication systems 10
53. ng current or designing future communication and computer networks systems and applications The following information is gathered from the UNIX on line documentation the MIL 3 Inc world wide web page the MIL 3 Inc sales pamphlets UNIX on line tutorials and telephonic interviews with sales personnel B ASSESSMENT CRITERIA 1 Accessibility OPNET Modeler can be installed on these platforms Sun SPARC Solaris 2X Sun SPARC Sun OS Digital Equipment Corporation OSF 1 Hewlett Packard UX Silicon Graphics IRIX and Intel based implementations of Windows NT 3 5 1 OPNET requires 75 megabytes MB of disk space for the software and 32 MB of Remote Access Memory RAM MIL 3 Inc recommends 120 MB of disk space and 64 MB of RAM OPNET requires access to an ANSI C compiler which is included with the Solaris and Sun packages 2 Completeness OPNET Modeler is a comprehensive product It models computers software WANs Local Area Networks LANs data channels or any other systems applications or processes the user wishes to create It includes the ability to model current and future technologies OPNET includes these protocol libraries Ethernet Token Ring Fiber Distributed Data Interface FDDI Asynchronous Transfer Mode ATM Frame Relay X 25 Link Access Procedure Balanced LAPB Transmission Control Protocol TCP Internet Protocol IP User Datagram Protocol UDP Routing Information Protocol RIP Distributed Queue Dual
54. ns Simulation Tools An Assessment of Current Technologies Geshwind Associates October 1992 Bailey Kemple Chase Object Oriented Modeling of Military Communications Networks Journal of the Operational Research Society Volume 45 Number 10 pp 1108 1122 1994 Chinni M J Military Government and Aerospace Simulation The Society for Computer Simulations Simulation Series Volume 28 Number 3 1996 Imagine That Inc About Extend http www imaginethatinc com March 1997 Jones J G Course Notes Modeling and Simulation with COMNET III CACI Products Company December 1994 Madisetti Gelenbe Walrand Modeling Analysis and Simulation of Computer and Telecommunication Systems IEEE Computer Society Press 1994 MIL 3 Inc OPNET Modeler http www mil3 com home html April 1997 SES Inc SES http www ses com www workbench html March 1997 59 INITIAL DISTRIBUTION LIST Defense Technical Information Center 0 ccc cece cece ec ccee cece cecees 2 8725 John J Kingman Road STE 0944 Fort Belvoir Virginia 22060 6218 e A A Naval Postgraduate School 411 Dyer Road Monterey California 93943 5101 Professor John Osmundson CC OS 2 ceca ccc ccceccccccccsccscccscceeeeeces Naval Postgraduate School Monterey California 93943 5101 Professor Donald van Z Wadsworth CC Wa ooooccccccccccncancconacocnncnoos Naval Postgraduate School Monterey
55. omprehensive tutorial a user s manual two volumes on modeling and two volumes of the OPNET Modeler simulation kernels No design specifications were available 8 Ease Of Use This product is fairly complicated to the new user OPNET Modeler has such detailed capabilities it is difficult for an inexperienced user to quickly grasp all of its qualities OPNET Modeler enables the user to model events at the process and state level The user continues with the nodal model and then integrates it all together in a network This provides the user with very powerful capabilities The user can vary the degree of depth of the programming parameters and events The user also has access to the entrance and exit criteria of the states The process and state level is the most basic breakdown of an element of a system This enables the user to establish the specific conditions required to enter or exit a state of a system This access is entirely in Proto CM a computer language very similar to C The manuals are extremely helpful but are oriented at the programmer level Many modeling concepts are just assumed Set up and run time depend on the model The basic models only a few nodes contained in the tutorial required between one and three hours of setup Each of these only took a few minutes to run It is difficult to adjust the speed of the simulation clock OPNET is designed to run as fast as it can The total execution time is dependent on the
56. otters are built into the model to gather statistics Results of the plotters can be immediately displayed on the screen The following are available to gather statistical information from the results D Binomial D Exponential D Gamma D Log Normal D Pascal D Poisson Gaussian Mean Random Random Get Seed Random Real Random Set Seed Standard Deviation Population Standard Deviation Sample Statistical Value Imagine That Inc 1995 pp 287 24 7 Documentation Extend has one book for its documentation Imagine That Inc 1995 It is very comprehensive Chapters 1 through 3 consist of a tutorial of Extend s basic features Chapter 4 is an overview of continuous and discrete modeling Chapter 5 discusses all of Extend s libraries Chapter 6 describes the methods to get data into and out of Extend The rest of the book provides a more in depth look at Extend modeling how to build icons and a list of common errors and their causes 8 Ease Of Use Extend is fairly easy to use Models are constructed with building blocks via windows and menus Double clicking on a building block provides access to the items attributes Extend s biggest challenge is the user must know the intricate details of the system or equipment to correctly model the functions and flow Set up time is dependent on the depth of the model The basic examples provided in the tutorial took about 15 minutes to create and only a few minutes to run Extend a
57. r an iterative run capability Workbench s basic features modeling with sub modules enables the user to model emerging system by breaking them down into their smallest elements 10 Extendibility Workbench uses a C based language Users can add C language procedures to be included in the simulation program These additions enable Workbench to be extended as necessary The user can access the code developed for the model 11 Extensibility Of Results The ability of the user to add C programming statements also enables the user to create new and alternative computers communication equipment and any other type of system This capability is limited by the user s ability to program in C language SES offers for a price extension products 12 Fidelity This product seems to provide realistic results consistent with the input parameters and model However Workbench is graph oriented programming which is 32 dependent on user definitions for its behavior Models can be developed with various levels of detail 13 Flexibility Nodes can be delayed or blocked simulating movement or destruction through a time activation probability distribution or a trigger Each of these must be created as part of the model 14 Interoperability Workbench can interoperate with most programs created in C C programs can be imported into the model and run as part of the simulation 15 Miscellaneous Workbench does not offer any
58. reate any communication or computer system Traffic flow architectures software protocols and data channels can be modeled This program is limited by the user s creativity modeling and programming skills Communication and computer icons can be modified to model alternate architectures 12 Fidelity This product provides results consistent with the input parameters and models Models can be developed with various degrees of detail 13 Flexibility Nodes can simulate movement and outages during run execution Outages can be triggered by counters probability distributions or the game clock Movements can be simulated via timed outages Once the network is modeled it takes little time to make modifications 14 Interoperability OPNET has an External Model Access EMA EMA is a technique of accessing a model external to the OPNET program MIL 3 1989 1996 pp EMA 3 This includes creating a model modifying a model or just extracting data from a model This is all supported via C programming language functions OPNET also has an External Compiler Interface ECI ECI permits the interfacing with third party compilers and linker programs 15 Miscellaneous Map overlays are available However they only provide a concept for the geographical locations of WANs satellite equipment and footprints and mobile cell layouts There is no integration of equipment with terrain density or elevation Outages can be implemented vi
59. s application sources message and response sources session sources transport commands and setup commands Upon completion of the run the user can immediately browse the results The following probability distributions are available in COMNET II e Beta e Geometric e Poisson e Erlang e Hyper exponential e Triangular e Exponential e Log normal e Uniform e Gamma e Normal e Weibull Each of these is available via a drop down menu in the parameters windows T Documentation COMNET IF s documentation consisted of one book It is oriented towards the network manager It does a great job of explaining the functions and capabilities of COMNET IH However it does not describe how to use COMNET II It is left up to the user to learn how to use the product A tutorial Sullivan 1996 was developed by a third party It provides step by step instructions on how to use the major features of COMNET II The lack of documentation did not hamper the author s ability to quickly learn and use the basic features of the product The menus and icons provide the user with an extremely user friendly flow for developing a model 8 Ease Of Use The product is very easy to use Network topologies are quickly developed using drag and drop icons and a menu driven environment Parameters are altered by double clicking on the various network objects Menu options enable the user to alter the game clock speed animate the run trace the run events a
60. s protocols and networks OPNET provides a friendly environment for building and analyzing communication and computer networks 12 Il COMNETII A INTRODUCTION COMNET HIM from the CACI Products Company is a network planning tool designed with an object oriented environment to model Local Area Networks LANs Wide Area Networks WANs and Metropolitan Area Networks MANS The network is created graphically and requires no actual code programming by the user Network technologies and traffic files can be imported from various systems Animation provides the user with the ability to monitor the flow of the network Building blocks objects a user is familiar with which include computer nodes routers and links may be edited to define specific characteristics of a network The basic steps to build a model using COMNET II are define the topology and establish traffic and computer loads The network is then verified for correctness and run The game clock and the run duration can easily be altered by the user Reports selected by the user are automatically generated during the run COMNET ID allows the user to CACI 1997 e Predict end to end delays throughputs and utilization of links buffers and processors e Reproduce random and bursty traffic patterns e See peaks and valleys of traffic not just snapshots and averages e Pinpoint sources of delays and bottlenecks The following information is gathered from the CACI Products Co
61. s which can be saved in the libraries They can also save models as templates to be used in other models This provides the user with the power to create the computers and equipment to be reused in later models Additionally a list of libraries available through third parties s available through Imagine That Inc 23 3 Configuration Management Imagine That Inc was founded in 1987 to market Extend software Extend is current on version 3 2 The user is responsible for managing input and output Extend permits hierarchical modeling The user via levels subroutines can make a complex system easy to build and easy to understand 4 Cost Extend is available for 695 00 The university price is 350 00 Technical support is free provided the user has purchased the most recent upgrade version Today s current upgrade from version 3 1 to version 3 2 is 99 00 Imagine That Inc does not offer any in house training programs 5 Data Input Methods Extend includes an input random number menu and an input data menu The first provides the user with a distribution selection and the latter permits the user to enter specific data values Extend uses text files for importing and exporting data Text files can be created in another application like a spreadsheet word processor or database then read into Extend and vice versa This is easier for inputting lists of files and for manipulating simulation results 6 Data Reduction Pl
62. se Menus and icons create a user friendly environment that provides the user with a graphical interface to modeling Workbench however is not designed to model any specific type of network It is a general modeling tool What this means is the libraries and icons have basic low level functions The user must create anything specific needed for the model The user needs to be a proficient modeler to get the maximum usage of this software 31 Workbench uses a top down modeling approach The user establishes a catalog with a main module and possibly some other generic modules Each module is then developed further as a sub module The user can travel back and forth between the levels of the modules and sub modules This level approach allows the user to break the model down into small manageable pieces The user manuals are easy to follow There is an index in the back of each book of the documentation The index provides a quick reference to all of the documentation manuals The manuals provide details and execution steps for most of the topics Once again run time and set up time are dependent on the detail of the model The user must design the model to the accuracy desired in the solution Workbench uses multithread processing to simulate numerous events occurring simultaneously The run length and run interval time or clock speed can be altered prior to the execution of the simulation 9 Experimental Design Workbench does not offe
63. ss G2 enables the user to model computers software and communication equipment through the use of Object Oriented Modeling Specific KBs must be developed by the user G2 provides the modeler with the capabilities to create not only the model but the interface that the operator will have with the simulation The operator can be prompted for input via toggle switches text inputs or interactive buttons The modeler can create an interactive on line simulation environment The Army Artificial Intelligence Center is currently using G2 37 3 Configuration Management Gensym Corporation was founded in 1986 Gensym Corporation currently provides services to over 30 countries which include petroleum companies chemical companies and other industrial companies The user is responsible for managing input and output files G2 graphically shows the objects within the designed system Data encapsulation or hiding is available to reduce clutter and access to some information Object relationships can be depicted by showing the workspace module hierarchy 4 Cost The current commercial cost for the G2 server license with Telewindows is 36 000 00 A minimum of one user license must be purchased at 4 800 00 User license prices decrease after the eleventh user The university cost is 500 00 The GSA cost is 31 of the commercial cost Customer service support is available for a yearly fee of 15 of the commercial list price 6 120 00 for a sing
64. t come last served preemptive resume processor sharing and round robin 3 Configuration Management SES founded in 1971 has evolved from a consulting and research organization to a global software and consulting firm For more than 25 years SES has been providing simulation technology to its customers The user is responsible for managing input and output files User s can specify which nodes to gather statistics A rerun will overwrite previous output files A user can view the modules and sub modules developed during the building of the model The main module is typically designed to be a complete diagram of the network or system being modeled 4 Cost A SES sales representative will help design a software package of Workbench and its associated files to meet the users needs Workbench s starting commercial price is 23 500 00 The university price is 500 00 The government price is 20 of the cost of the civilian priced package Technical support and upgrade costs are 15 of the original package price Training is available at SES Regional Sites for 8 000 00 per person This is for the three day introductory course The Network Framework Library consisting of X 25 TCP ATM FDDI SNA Client Server and Ethernet can be purchased for 5 000 00 civilian price SES also has a huge list of partially developed models These models are free and can be requested as needed 30 de Data Input Methods Users can input data
65. total number of events the complexity of each node and state and the type of platform the simulation is being executed on The user can speed up the simulation slightly by leaving out the debugging option during the execution Also the simulation can be forced to run at real time by establishing a comparison of the game clock with the real clock 9 Experimental Design This product allows the user to execute iterative runs Various probes can be set up for each of the runs Separate output data files must be established prior to the execution State and process level modeling enables the user to develop models of emerging technologies 10 Extendibility OPNET can easily be modified The user must first access the desired level to be altered then right click on the item to be altered This provides the user with the parameter menu Additionally OPNET offers the option of an attributes menu This menu will allow the user to input specific numbers immediately prior to the run s execution OPNET Model uses Proto CTM coding Immediate access by the user to the entire model s code is not available The user has open access to the entrance and exit coding for the state diagrams Also if an error occurs during compiling or execution a text editor with the subroutine containing the error will be accessible to the user 11 Extensibility Of Results OPNET Model s ability to model at the state level enables the user to literally c
66. training can be requested at the user s location The pricing of this option is dependent on the location facilities and instruction requested S Data Input Methods OPNET in addition to using predefined Generator Modules Ideal and Clock uses stochastic traffic sources based on a user selected probability function for creating message inter arrival times and uses deterministic sources to specify exact times for message packet generation A regenerative source can be used to create bursty transmissions Tables are used to prompt the user for data through out the development of the model External Model Access includes the capability to extract data from another model See Interoperability for additional information 6 Data Reduction OPNET Modeler provides immediate accessibility to probe data collection method results This data can be formulated into graphs and reports The probes are user selected and include node statistics link statistics global statistics and simulation attributes The following probability distributions are available in OPNET Modeler e Bernoulli e Erlang e Poisson e Chi Squared e Exponential e Uniform e Constant e Normal e Uniform Integer These can each be utilized via menu options T Documentation On line documentation is included with the UNIX packages Hard copy documentation can be purchased for 500 00 a copy The documentation is very detailed and informative It includes a c
67. veloped by Imagine That Inc is an advanced simulation tool designed to develop dynamic models of real life processes It enables the user to predict the course and results of certain actions understand why observed events occur identify problem areas before implementation explore the effects of modifications confirm that all variables are known evaluate ideas and identify ineffectiveness gain insight and stimulate creative thinking and communicate the integrity and feasibility of plans Imagine That Inc 1995 pp 4 B ASSESSMENT CRITERIA 1 Accessibility Extend is available for Windows 3 1 or later Windows 95 Windows NT Macintosh 6 7 or later and Power Macintosh System 7 10 MB of hard disk space are required for the Windows version and 8 MB of hard disk space are required for the Macintosh version Both platforms require 4 MB of RAM but 8 MB are recommended Models built on either platform can be run on the other platform For example if you build a model or library on a Macintosh computer it can easily be read on a Windows computer 2 Completeness Extend uses icons or building blocks to build models 15 libraries of various building blocks are included with Extend The building blocks represent the smallest level or function of amodel The user must build computers communications equipment systems etc from the basic functions and flows This requires the user to be proficient in modeling Users can create new icon

Author(s) Gebhardt, Heidi L Title Communication

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