Modelarea retelelor de comunicatii prin simulare. Analiza statistica a rezultatelor simularii

CUPRINS:
|pag.                                                                          |
|I.   |INTRODUCERE ÎN MODELAREA REŢELELOR DE                              |8    |
|     |COMUNICAŢII........................................................|     |
|     |.................................                                  |     |
|1.1.       |Consideraţii                                                |8    |
|           |tehnico-tactice.............................................|     |
|           |............................................................|     |
|           |..............................                              |     |
|1.2.       |Procesul de modelare.                                       |9    |
|           |Generalităţi..…………………………………………………………………………………..             |     |
|1.3.       |Desfăşurarea unui studiu de                                 |11   |
|           |modelare..…………………………………………………………………………..                    |     |
|1.3.1.            |Avantajele modelării cu şiruri de                    |11   |
|                  |aşteptare..……………………………………………………                      |     |
|1.3.2.            |Principiile desfăşurării unui studiu de              |11   |
|                  |modelare..…………………………………………                           |     |
|1.4.       |Algoritm de modelare. Schemă de                             |13   |
|           |modelare..………………………………………………………………                          |     |
|1.5.       |Modelarea                                                   |15   |
|           |cantitativă..………………………………………………………………………………………………………………     |     |
|1.6.       |Modelarea                                                   |15   |
|           |calitativă..…………………………………………………………………………………………………………………     |     |
|1.7.       |Modelarea prin                                              |16   |
|           |simulare..………………………………………………………………………………………………………..         |     |
|1.7.1.            |Simulatorul..…………………………………………………………………………………………………………|16   |
|                  |…………                                                 |     |
|1.7.2.            |Tehnici de                                           |18   |
|                  |simulare.............................................|     |
|                  |.....................................................|     |
|                  |.......................................              |     |
|1.7.3.            |Analiza statistică a rezultatelor                    |20   |
|                  |simulării..………………………………………………………..                   |     |
|     |                                                                   |     |
|II.  |PRINCIPIILE MODELĂRII SOFT A REŢELELOR DE                          |22   |
|     |COMUNICAŢII..…………………………………………………....................               |     |
|2.1.       |Asamblarea soft a nodului de                                |22   |
|           |comunicaţii..…………………………………………………………………...                   |     |
|2.1.1.            |Structura unui nod de                                |23   |
|                  |comunicaţii………………………………………………………………….……              |     |
|2.1.2.            |Realizarea fişierelor                                |24   |
|                  |NODE_XY.CPP…………………………………………………………………                 |     |
|2.1.3.            |Modelarea soft a modulului "GENERATOR DE             |25   |
|                  |PACHETE"………………….                                     |     |
|2.1.4.            |Modelarea soft a modulului                           |28   |
|                  |"SINK"…………………………………………………………………....                  |     |
|2.1.5.            |Modelarea soft a modulului "COMUTATOR DE             |30   |
|                  |PACHETE"………………..                                     |     |
|2.2.       |Asamblarea soft a subreţelei de                             |33   |
|           |comunicaţii………………………………………………………………..                       |     |
|2.2.1.            |Descrierea ierarhică a                               |33   |
|                  |subreţelei………………………………………………………………….……...            |     |
|2.2.2.            |Completări realizate în fişierul                     |37   |
|                  |MAIN.CPP……………………………………………………..                       |     |
|2.2.3.            |Fişierul                                             |39   |
|                  |LOCAL.H………………………………………………………………….……………………………………      |     |
|2.3        |Programul ROUT97………………………………………………………………….………………………………………………|40   |
|     |                                                                   |     |
|III. |PREZENTAREA UNOR PROGRAME DE FIRMĂ: "COMNET                        |43   |
|     |III"……………………………………………………………..................                      |     |
|3.1.       |Descriere………………………………………………………………….…………………………………………………………………|43   |
|           |……..                                                        |     |
|3.2.       |Aplicabilitate…………………………………………………………………...………………………………………………|43   |
|           |……………..                                                     |     |
|3.3.       |Abordare                                                    |44   |
|           |generală………………………………………………………………….…………………………………………………..     |     |
|3.4.       |Tipuri de reţele                                            |45   |
|           |modelate………………………………………………………………….……………………………………..          |     |
|3.5.       |Alegerea nivelului corect de detaliere a                    |46   |
|           |modelului……………………………………………………                               |     |
|3.6.       |Cele mai uzuale                                             |47   |
|           |aplicaţii………………………………………………………………….………………………………………          |     |
|     |                                                                   |     |
|IV.  |ETAPELE MODELĂRII ŞI SIMULĂRII UNEI REŢELE DE COMUNICAŢII FOLOSIND |49   |
|     |COMNET .......................                                     |     |
|4.1.       |Generalităţi………………………………………………………………….…………………………………………………………|49   |
|           |……….                                                        |     |
|4.2.       |Construirea topologiei                                      |50   |
|           |reţelei………………………………………………………………….…………………………….               |     |
|4.2.1.            |Noduri………………………………………………………………….………………………………………………………|50   |
|                  |……                                                   |     |
|4.2.2.            |Legături………………………………………………………………….…………………………………………………|51   |
|                  |……...                                                |     |
|4.2.3.            |Subreţele……………………………………………………………….…………………………………………………|52   |
|                  |……….                                                 |     |
|4.2.4.            |Reţele de                                            |52   |
|                  |tranzit…………………………………………………………………………………………………………….    |     |
|4.2.5.            |Nori                                                 |53   |
|                  |WAN………………………………………………………………………………………………………………………..   |     |
|4.2.6.            |Arce şi                                              |53   |
|                  |porturi……………………………………………………………………………………………………………….   |     |
|           |                                                            |     |
|4.3.       |Adăugarea traficului şi încărcării                          |54   |
|           |reţelei………………………………………………………………………..                        |     |
|4.3.1.            |Programarea (temporizarea)                           |54   |
|                  |surselor………………………………………………………………..                   |     |
|4.3.2.            |Aplicaţii……………………………………………………………….…………………………………………………|55   |
|                  |………...                                               |     |
|4.4.       |Definirea algoritmilor de rutare şi a protocoalelor de      |56   |
|           |transport………………………                                          |     |
|4.4.1.            |Algoritmi de                                         |56   |
|                  |rutare……………………………………………………………………………………………………...      |     |
|4.4.2.            |Protocoale de                                        |59   |
|                  |transport…………………………………………………………………………………………….        |     |
|4.5.       |Setarea parametrilor                                        |60   |
|           |simulării…………………………………………………………………………………………….               |     |
|4.6.       |Generarea                                                   |60   |
|           |rezultatelor…........................……………………………………………………………|     |
|           |………………………….                                                 |     |
|4.7.       |Distribuţii statistice definite de                          |61   |
|           |utilizator……………………………………………………………………….                      |     |
|4.8.       |Biblioteci de                                               |61   |
|           |obiecte……………………………………………………………………………………………………………………         |     |
|4.9.       |Fişierele                                                   |61   |
|           |modelului………………………………………………………………………………………………………………………      |     |
|     |                                                                   |     |
|V.   |DESCRIEREA MODELĂRII ORIENTATE PE                                  |62   |
|     |OBIECTE……………………………………………………………………………….................             |     |
|5.1.       |Descriere                                                   |62   |
|           |generală……………………………………………………………………………………………………………………….      |     |
|5.2.       |Bilioteca de                                                |64   |
|           |obiecte……………………………………………………………………………………………………………………...      |     |
|5.2.1.            |Sursa de                                             |64   |
|                  |apeluri……………………………………………………………………………………………………………     |     |
|5.2.2.            |Legătura                                             |67   |
|                  |punct-la-punct……………………………………………………………………………………………    |     |
|5.2.3.            |Nodul de                                             |76   |
|                  |procesare……………………………………………………………………………………………………..    |     |
|5.2.4.            |Dispozitivul de                                      |90   |
|                  |reţea………………………………………………………………........................|     |
|                  |................................                     |     |
|5.3.       |Clase de                                                    |93   |
|           |rutare………………………………………………………………………………………………………………………………      |     |
|5.4.       |Algoritmi de                                                |94   |
|           |rutare……………………………………………………………………………………………………………………..        |     |
|5.4.1.            |Drumul                                               |95   |
|                  |minim………………………………………………………………………………………………………………..    |     |
|5.4.2.            |Penalizare minimă. Tabele de                         |97   |
|                  |penalizare…………………………………………………………                     |     |
|5.4.3.            |Tabele de rutare definite de                         |98   |
|                  |utilzator………………………………………………………………….                  |     |
|     |                                                                   |     |
|VI.  |APLICAŢIE PRACTICĂ REALIZATĂ CU PROGRAMUL COMNET III               |101  |
|     |………………………………………………………………..                                         |     |
|6.1.         |Premize……………………………………………………………….……………………………………………………………………|101  |
|             |….                                                        |     |
|6.2.         |Construirea                                               |103  |
|             |modelului………………………………………………………………………………………………………..        |     |
|6.2.1.            |Topologia                                            |104  |
|                  |reţelei……………………………………………………………….…………………………………………………..|     |
|6.2.2.            |Adăugarea traficului în                              |109  |
|                  |reţea……………………………………………………………….…………………                |     |
|6.2.3.            |Definirea algoritmilor de                            |112  |
|                  |rutare……………………………………………………………………………                  |     |
|6.2.4.            |Setarea parametrilor                                 |113  |
|                  |simulării………………………………………………………………………………              |     |
|6.2.5.            |Generarea                                            |113  |
|                  |rezultatelor……………………………………………………….……………………………………..   |     |
|6.3.         |Interpretarea                                             |116  |
|             |rezultatelor……………………………………………………………….………………………………..       |     |
|6.3.1.            |Micşorarea numărului de                              |117  |
|                  |canale………………………………………………………………………….                  |     |
|6.3.2.            |Defectarea componentelor                             |118  |
|                  |reţelei………………………………………………………………………...                |     |
|6.3.3.            |Creşterea                                            |121  |
|                  |traficului……………………………………………………………………………………………………..   |     |
|     |                                                                   |     |
|VII. |OBSERVAŢII ŞI                                                      |123  |
|     |CONCLUZII………………………………………………………………..................................|     |
|     |...........................................................        |     |
|     |                                                                   |     |
|VIII.|ANEXE………………………………………………………………......................................|125  |
|     |...................................................................|     |
|     |.......................................                            |     |
|A.1.         |Schema bloc a Centrului de Transmisiuni de                |126  |
|             |Instrucţie………………………………….                                  |     |
|A.2.         |Modelul COMNET III al Centrului de Transmisiuni de        |127  |
|             |Instrucţie………….                                           |     |
|A.3.         |Distribuţii statistice utilizate în                       |128  |
|             |aplicaţie…………………………………………………………………                        |     |
|A.4.         |Exemple de monitorizări ale parametrilor                  |129  |
|             |modelului……………………………………..                                 |     |
|A.5.         |Raport statistic al                                       |130  |
|             |aplicaţiei…………………………………...................................|     |
|             |................................................          |     |
|     |                                                                   |     |
|IX.  |BIBLIOGRAFIE………………………………….………………………………….………………………………….…………………………………|138  |
|     |………………………                                                          |     |