JPH117421A - Network simulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate processing such as the suspension of simulation which considers node movement, model creation and data writing and to improve processing efficiency by providing a function which autonomously changes the position of self-device to a node for which mobility is required. SOLUTION: When a time that is regulated by a movement management table is reached in the process of data transfer, an interruption occurs from a timer process module to a movement management process module. The movement management process module notifies to a data transfer control process module that it moves to a position that is regulated by the movement management table. The data transfer control process module suspends data transfer, cuts off its connection with a subnetwork '010' and connects it to a defined position (subnetwork '011' in this case). The data transfer control process module notifies to the movement management process module that the movement is completed and resumes the data transfer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a network simulator. Particularly, in a network system in which a plurality of sub-networks composed of a plurality of nodes (or hosts) are connected to each other via a backbone network, a network simulator suitable for simulating communication traffic and the like between the nodes. It is suitable for.

[0002]

2. Description of the Related Art A network simulator is a system in which a new communication protocol is added, a new function is added to an existing communication protocol, or a combination of new and old communication protocols is changed. This system is used to quantitatively display the validity or to evaluate the validity of a network topology composed of nodes that implement these communication protocols.

Conventionally, a communication network to be evaluated is mounted on each node to form a partial network, and a simulated data transfer is actually performed on the partial network to evaluate the communication protocol. Is used.

Referring to FIG. 2, an example of a conventional network simulator to which such a method is applied will be described.

FIG. 2 shows an example of a network system to which this type of network simulator is applied. This network system includes three sub-networks “010” in a butterfly network “020”,
"011" and "012" are connected.

Here, it is assumed that nodes "000" and "001" are connected to the sub-network "010". Also, the sub-network "011"
It is assumed that the node “002” is connected. Further, the node “00” is added to the sub-network “012”.
3 "is connected.

For this reason, the nodes "001" and "0"
03 ", the data transfer between the sub-network" 01
0 "-backbone network" 020 "-subnetwork" 012 ".

FIG. 3 shows the internal configuration of each node.

[0009] Timer process module "100"
Is a module for referring to the time at which the data generation process module “101” or the data collection process module “102” inserts data, and for generating an interrupt at a certain set time. The time referred to by the timer process module “100” may be an absolute time indicated by a clock provided in the system or a relative time from the start of the simulation.

[0010] Data generation process module "101"
Is a module for generating data to be transmitted. The data generation interval may be a network simulation such as an exponential distribution or a k-Ehlan distribution, and follows the model used. The destination designation of the data may be fixed or may be randomly selected.

The data collection process module "102"
Is a module that extracts only data used in the data analysis process module “103” from all received data.

Data analysis process module "103"
Is a module that analyzes the extracted data received from the data collection process module “102” and creates data for simulation.

The simulation process module "10
4 ”evaluates / analyzes the analysis data received from the data analysis process module“ 103 ”according to a user request.
Module to display.

The communication protocol "110" comprises three modules: a data transfer control process module "111", a data transmission process module "112", and a data reception process module "113".

The data transfer control process module “11”
“1” encapsulates the data received from the data generation process module “101” and passes it to the data transmission process module “112”.

The data transfer control process module “111” is provided with a data reception process module “11”.
The content is extracted from the data received from “3” and passed to the data collection process module “102”.

In addition, the data transfer control process module "111" also performs flow control, retransmission control, route control and the like.

Data transmission process module "112"
Is a module for transmitting the data received from the data transfer control process module “111” to the destination node.

Data receiving process module "113"
Is a module that receives data addressed to itself and passes it to the data transfer control process module “111”.

Each process module is generated not as a hardware device but as a process, and exchange between process modules is performed by message communication between processes.

Conventionally, in the simulation process module "104", the propagation delay is determined from information such as the occurrence time and the collection time, and the load is determined from information such as the number of packets (or the number of bits or bytes) received per unit time. Simulation was performed by displaying / evaluating the data and throughput.

However, in this method, there are problems such as a place where the network is arranged, a space problem for securing the number of nodes, an economic problem, and the like, and a large-scale network cannot be simulated. Was.

Therefore, conventionally, in order to solve the above problem,
There is known a method of performing a network simulation by modeling a simulated network with one simulation program and executing the simulation program on one CPU.

The simulation program will be described. The configuration of the network system is based on the configuration of FIG. 2 described above, and the internal configuration of the node is also based on the configuration of FIG. However, in this case, a communication protocol modeled for simulation is used as the communication protocol “110” in FIG. 3 instead of implementing a communication protocol actually used.

When this method is applied, logically, the number of nodes and the scale of the network can be arranged without limitation, so that an arbitrary large-scale network can be simulated.

However, none of the above methods basically takes into account the mobility of the nodes, and thus cannot cope with a network simulation in which the network topology changes with time.

[0027]

In recent years, the performance, size, weight, and power consumption of terminal devices have been rapidly increasing. As a result, there are two types of terminal devices, a semi-mobile type in which the communication position is different from the communication position used in the previous communication, and a completely mobile type in which the communication position is sequentially changed during communication. Demand is growing as a form.

As for the communication protocol, not only the conventional communication protocol on a fixed network but also
Standardization of communication protocols in consideration of mobility, such as wireless LAN, IPv6, and VIP, is being promoted.

Therefore, in order to realize the above-mentioned request and to construct a system so that the system can be effectively used, each node is provided with a communication protocol in consideration of mobility, and includes a node which moves with time. In a network topology, it is necessary to quantitatively evaluate and display network performance such as propagation delay, load, and throughput, so that the use form can be validated, validated, or optimized.

However, in the conventional network simulator, all the nodes are fixedly connected to the respective sub-networks, and the movement of the nodes themselves is not allowed, so that the network topology changes with time. In this case, it cannot be applied and cannot be applied as it is.

For example, in order to simulate a network topology including a mobile node such as a mobile terminal, a plurality of network models are first created, a simulation is performed using one model, and then the simulation is temporarily performed. You have to stop and then load another network model and run the simulation again.

If a plurality of network models are not prepared, the simulation must be executed after rewriting the network model every time the simulation is interrupted.

However, the current method of creating a plurality of network models, temporarily suspending the network simulation, and then executing a simulation or the like based on another network model or the like is clearly inefficient and has a disadvantage in practice. However, there is a problem that it is not possible to faithfully cope with the network topology.

[0034]

According to the present invention, a plurality of sub-networks interconnected via a backbone network and a plurality of sub-networks connected to one of the plurality of sub-networks are provided. A network simulator for processing a network system including nodes is characterized as follows.

That is, (1) a communication protocol for controlling communication between itself and another node, and (2) a timer process for giving time information, to each of a plurality of nodes requiring mobility. And (3) a movement management table that defines the movement of the node over time on the network, and (4) a movement management table that is monitored based on time information given from the timer process unit, and A movement management process unit that interrupts the communication protocol each time the movement reaches a designated time, and (5) a data collection and analysis process unit that collects and analyzes information related to communication by the communication protocol.

As described above, for a node requiring mobility, a function capable of autonomously changing the position of its own device is provided, so that the simulation operation is interrupted or the model is created in consideration of the movement of the node. In addition, processing such as data writing can be eliminated and processing can be efficiently performed.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION

(A) Embodiment Hereinafter, an embodiment of a network simulator according to the present invention will be described with reference to the drawings. Note that the embodiment described here is characterized in that in order to solve the above-described problem, a means for autonomously moving each node is provided.

(B) Configuration of Network System to be Simulated FIG. 1 shows a configuration example of a network system including nodes having mobility. Here, FIG. 1 shows the same as FIG.
Corresponding parts are indicated by the same reference numerals.

Therefore, in the network system of FIG. 1, nodes "000", "002", and "003" and sub-networks "010", "011", and "012"
The configuration and connection of the backbone network “020” are the same as those of the network system described with reference to FIG.

The difference between the network system shown in FIG. 1 and FIG. 2 is that node "001" is a mobile node.

That is, this node “001” is initially connected to the sub-network “010”,
The difference is that the node moves to the position of the node “001a” over time and is connected to another sub-network “011”.

Therefore, when the mobile node “001” communicates with the node “003”, first, the sub-network “010” -the backbone network “020”
-"Start data transfer via sub-network" 012 ", but as time elapses, node" 001 "
After moving to the position of “a”, the sub-network “01”
1 "-backbone network" 020 "-subnetwork" 012 ".

(C) Configuration Provided in Mobile Node FIG. 4 shows an internal configuration applied to a mobile node. As for the other fixed nodes, as shown in FIG.
A network simulation is executed using a node having the internal configuration shown in FIG.

FIG. 4 shows the same or corresponding parts as those in FIG.
It has the same configuration except that the communication protocol “210” is substituted for “10” and the mobility management process module “200” and the mobility management table “201” are newly provided.

The communication protocol "210" includes a data transfer control process module "211", a data transmission process module "212", and a data reception process module "213". , IPv6, VIP, and the like.

The movement management table "201" defines movement of a node, and is a table specified by a user.

Movement management process module "200"
Is a module that refers to the movement management table “201” and moves a node to a specified position at a specified time.

FIG. 5 shows the structure of the mobility management table "201". In FIG. 5, t0, t1, t2,... Tn indicate time. The time may be an absolute time or a relative time from the start of the simulation. Also, p
0, p1, p2,... Pn indicate the position of the node corresponding to the time. The position of the node may be a physical position or a logical position such as a subnetwork number.

As described above, the movement management table "201"
Has at least two pieces of information, time and position.

(D) Simulation Operation The final evaluation and display of the simulation result are executed in the simulation process “104”.
This network simulation process will be described.

(1) Initial Setting As shown by the broken line in FIG. 1, the mobile node “001” is initially connected to the sub-network “010”.

The movement management table "201" in FIG.
Defines a simulation start time t0 and a position p0 of the sub-network "010" as the first entry.

The movement management process module “20”
"0" refers to the movement management table "201" and refers to the time (t1, t) specified in the movement management table "201".
2,... Tn), the timer process module “100” is set to generate an interrupt.

(2) Simulation Operation When the simulation is started, the data generation process module “101” generates data according to the above-described model such as the exponential distribution or the k-Ehlan distribution, and sets the data transmission destination to the node “003”. The communication protocol "21
Pass data to "0".

When the data transfer control process module “211” of the communication protocol “210” receives this data from the data generation process module “101”,
Data transmission is started through the data transmission process module “212”.

As a result, between the mobile node “001” and the node “003”, the sub-network “010” −
Data transfer starts through the sub-network “012” -backbone network “020”.

During data transfer, mobile node "001"
Receives data from the node “003” through the data reception process module “213” of the communication protocol “210”, and receives the data transfer control process module “21”.
1 ”to the data collection process module“ 102 ”.

Data collection process module "102"
Extracts data to be simulated from the received data, and passes the data to the data analysis process “103”.

Data analysis process module "103"
Analyzes the extracted data received from the data collection process module “102” and passes it to the simulation process module “104”.

During the data transfer, the movement management table “20”
When the time (t1) specified by “1” is reached, an interrupt occurs from the timer process module “100” to the mobility management process module “200”.

Movement management process module "200"
When an interrupt occurs, the communication protocol "210"
To the data transfer control process module “211” of the transfer management table “201” to the position (p1) specified by the transfer management table “201”.

The data transfer control process module “21”
When notified of the move from the mobility management process module “200”, the data transfer is interrupted, the connection with the sub-network “010” (FIG. 1) is cut off, and the position defined by p1 (in this case, Is the subnetwork "01
1)).

When the connection to the sub-network “011” is completed, the data transfer control process module “2”
"11" notifies the transfer management process module "200" of the completion of the transfer, and restarts the data transfer.

Then, the above process is repeated until t2,..., Tn, and the simulation ends.

The simulation process module “10”
The data recorded in “4” is displayed / evaluated according to the user's request.

Note that these process modules are generated not as hardware devices but as processes, and exchange between process modules is performed by inter-process message communication.

(E) Effects of the Embodiment As described above, according to the network simulator of the present embodiment, the node “001” is provided with the mobility management table “201” that defines the autonomous movement, and the A network simulator capable of efficiently executing a simulation without rewriting a model or interrupting a simulation by providing a mobility management process module “200” that manages connection with a subnetwork based on the network management process module. Can be.

(F) Other Embodiments In the above embodiment, only the node “001” has been described as a mobile node. However, if the internal configuration of FIG. 4 is applied to all nodes on the network, Thus, it is possible to realize a system capable of executing a simulation operation in a situation where each node moves independently without interrupting the system or rewriting data.

[0069]

As described above, according to the present invention,

[Brief description of the drawings]

FIG. 1 is a block diagram showing a network configuration to be processed by a network simulator according to an embodiment.

FIG. 2 is a block diagram showing a network configuration to be processed by a conventional network simulator.

FIG. 3 is a block diagram showing an internal configuration of each node used by a conventional network simulator.

FIG. 4 is a block diagram illustrating an internal configuration of each node used by the network simulator according to the embodiment.

FIG. 5 is a table showing an internal configuration of a movement management table.

[Explanation of symbols]

"000", "002", "003" ... node, "01"
0 "," 011 "," 012 "... subnetwork,
“020”: Backbone network.

Claims (1)

[Claims] 1. A network simulator for processing a network system including a plurality of sub-networks interconnected via a backbone network and a plurality of nodes connected to any of the plurality of sub-networks. A communication protocol for controlling communication between itself and another node among the plurality of nodes requiring mobility, a timer process unit for giving time information, A movement management table that defines the movement of the position over time, and a movement management table based on time information given from the timer process unit. Mobility management process section that interrupts And a data collection / analysis processing unit for collecting and analyzing information related to communication by the network simulator.