Tutorials to .com

Tutorials to .com » Mechine » Eda-pld » OPNET-based small-scale network simulation and analysis

OPNET-based small-scale network simulation and analysis

Print View , by: iSee ,Total views: 22 ,Word Count: 1222 ,Date: Mon, 22 Jun 2009 Time: 5:22 AM

0 Introduction

Network simulation is a mathematical modeling and simulation of statistical analysis of network behavior, in order to gain the characteristic parameters of specific network technologies. People to create a new network protocol or communication standards, such as when, in order to know their network performance such as throughput, network latency and so on, can not be separated from network simulation. At present, network simulation technology has gradually become the network planning, design and development of mainstream technology. Information technology in today's era of rapid development, people's demand for network communications is also rising. With more and more the size of network, network complexity continue to become larger, the network performance has become increasingly unpredictable, and therefore the requirements of the simulation software is also getting higher and higher. The current commonly used type of network simulation software, rich mainly in Berkeley NS, OMNeT + +, SSFNET, OPNET and so on. OPNET is - a powerful object-oriented communication network simulation environment, and now has been more and more researchers of all ages. Text by OPNET simulation to analyze a small star-shaped network through a router plus a star-shaped network, the network delay and server load changes, and analysis of simulation results from a fixed host to a number of small companies should use the kind of topology.

1 star network topology and OPNET Simulation Software

Star-shaped network topology each computer is using their own cable to connect to the network, there are problems if a site will not affect the operation of the entire network. Easy to maintain the structure through the exchange of cables and workstations can easily be a simple way to determine the network point of failure. The entire network will not be a site affected by the fault, the network node to facilitate change is now the most commonly used network topology.

OPNET is a network-based discrete event simulation software, which means the use of hierarchical modeling, which is divided into the process of modeling, modeling and network modeling node three. Process simulation modeling the behavior of individual objects, the use of finite state machine model; nodes through the use of modeling is to describe the different modules of the different actors node object to display the network devices and systems architecture; network modeling is built in the node mode after the completion of phase behavior, which is responsible for the node model of the equipment set up in the Internet into the network, edit the network topology.

OPNET simulation software's main features include: the use of object-oriented technology; event-based finite state machine modeling; wireless network model nested; provide details of the basic model-base; discrete event driven simulation mechanism; efficient simulation engine ; provides a wide range of business models; completely open system; integrated interactive debugging tools; a wealth of statistics and analysis of functional integration.

2 Network Simulation and Analysis

Suppose in a laboratory, there are 30 hosts, the laboratory has a star-network topology, the addition of a laboratory (15 hosts), in the increase in the same laboratory is a star topology, through the router to connecting two networks, according to analysis of simulation results for additional load in the case of whether this will seriously affect network performance. Two types of network topology as follows:

OPNET-based small-scale network simulation and analysis

Picture not clear? Click here to view the image (larger).

In Figure 1, the use of a switch, the external node 30 on behalf of the host laboratory, Figure 2 through a router in the two laboratories in the network connections together. In these two network switch of choice for the 3C-SSII a 1100-3300-4s-ae52 a e48 a ge3, routers Cisco2514, Link chose 10BaseT unshielded twisted pair.

Choice of simulation statistics for the server load and network latency, simulation time is 0.5h, the seed number of 128, simulation results are as follows:

OPNET-based small-scale network simulation and analysis

Picture not clear? Click here to view the image (larger).

On behalf of the red curve in Fig unextended network, blue, after the representative of the network expansion. By the simulation results can be seen in the increase in the external network, the network changes in the load remains relatively stable, there has been no trend of monotonically increasing, the expanded network can still operate stably, and then can be seen from Figure 4 , despite the expansion of the network load increased, but the network latency and no obvious change, and ultimately all about 0.004s.

OPNET-based small-scale network simulation and analysis

Picture not clear? Click here to view the image (larger).

In other cases, the following analysis, assume that a company has two offices, there are a host 30 units, there are a host of Taiwan 15, in which a topology as shown in Figure 2, below there is a topology structure, as shown in Figure 5:

OPNET-based small-scale network simulation and analysis

Picture not clear? Click here to view the image (larger).

And 2 compared to the topological structure of a switch only, not using a router, comparing the two types of simulation statistics topology results as follows:

OPNET-based small-scale network simulation and analysis

Picture not clear? Click here to view the image (larger).

The results can be seen from the show, both network topology and stable operation of all, they more or less the same load and network latency is also roughly the same. As can be seen from the simulation results, two topologies for the network in general is the same, so a small company to configure the network structure, the two structures appear to be any choice. However, in today's world, we are about to do anything to save a simple, cost-effective. So from an economic point of view, we should choose the topology of Figure 5, as in the structure, not only to guarantee the performance of the network is not reduced, but also a router, a switch and the overhead costs of a number of twisted-pair .

3 summarizes

0PNET paper describes the mechanism simulation software modeling and simulation features, and through simulation analysis of a star-shaped network in the network increases, the network performance changes, the results show that the network can still operate stably. At the same time, through network simulation for a small company the best choice of a cost-effective network topology.


EDA/PLD Articles


Can't Find What You're Looking For?


Rating: Not yet rated

Comments

No comments posted.