JP3485066B2 - Traffic generator equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traffic generator device, and more particularly to a traffic generator device serving as a virtual client and a virtual server for simulating a terminal operation.

[0002]

2. Description of the Related Art In order to provide QoS (Quality of Service) that effectively uses a limited network band, TCP / IP (Transmissio) closer to the application level is provided.
n Control Protocol / Internet Protocol (TCP) or UDP (User Datagram Protocol) port number control devices (layer 4 switches, etc.) are currently being introduced. When evaluating such a control device, considering the environment in which it is actually used, a plurality of terminals are required and it is difficult to operate. Therefore, the control device is evaluated by using a traffic generator device that serves as a virtual server and a virtual client as a device that simulates a terminal operation.

FIG. 16 shows a sequence diagram of an example of an evaluation method by a conventional traffic generator device. In the figure, the virtual client sends a SYN packet to the virtual server to establish line character synchronization (step S1). When the virtual server receives the SYN packet, the (SYN + ACK) packet is transmitted to the virtual client (step S2), and in response thereto, the virtual client transmits the ACK packet to the virtual server (step S3). This completes the connection process.

Then, the virtual server sends a FIN packet to the virtual client (step S4). Upon receiving the FIN packet, the virtual client returns the (FIN + ACK) packet to the virtual server (step S
5). When the virtual server receives the above (FIN + ACK) packet, it transmits an ACK packet to the virtual client (step S6). This ends the disconnection process. By the above sequence of repeating only connection and disconnection of the connection, the operation of the virtual server and the virtual client is simulated by the conventional traffic generator device.

As another example of the conventional traffic generator device, as shown in the sequence diagram of FIG.
There is also known a device that does not form a connection and simply flows data unilaterally from a virtual client to a virtual server.

[0006]

By the way, in reality, there is a series of flows of connection processing, data transmission and response, and disconnection processing, in which the influence of the amount of data for each connection and the buffer status of the receiving terminal for each connection. The influence of the data transfer amount disturbance due to
The delay of CK transmission must also be considered.

However, in the conventional traffic generator device that repeats only connection and disconnection of the above connection and the conventional traffic generator device that only unidirectionally flows data, the influence of the data amount of each connection and the connection There is a problem in that it is not possible to make an evaluation close to the actual environment because it is not possible to consider the influence of the data transfer amount disorder due to the buffer state of the receiving terminal, the data waiting due to the processing, and the delay of ACK transmission.

The present invention has been made in view of the above points,
An object of the present invention is to provide a traffic generator device capable of performing an evaluation closer to the actual environment by simultaneously simulating both the connection and the data amount of each connection.

[0009]

In order to achieve the above object, the present invention provides a virtual client port connected to an evaluation target device and system, a virtual server port connected to the evaluation target device and system, and a virtual server port. A first parameter related to the data and the address transmitted from the client port and a second parameter related to the data and the address transmitted from the virtual server port are respectively set and saved, and a first parameter stored in the saving unit. From one of the virtual client port and the virtual server port, a connection process that transmits and responds to a predetermined packet between the virtual client port and the virtual server port based on the first and second parameters via the evaluation target device and system. Data transmission processing that transmits data packets to the other It is obtained by sending and the cutting process of a response and traffic means sequentially performs configured to have. In the present invention, the connection and the data amount for each connection are simultaneously simulated.

Here, the above-mentioned traffic means is configured such that, during the data transmission process, even if a predetermined retransmission timer time elapses after the data packet is transmitted from the data transmission side port of the virtual client port and the virtual server port, the data reception side. When the response packet transmitted from the port is not received by the data transmitting side port, a retransmitting unit may be included to retransmit the corresponding data packet from the data transmitting side port.

In the data transmission process, the traffic means delays a predetermined data transmission stored in the storage means after starting the data packet transmission from the data transmission side port of the virtual client port and the virtual server port. When the response packet from the data receiving side port is received at the data transmitting side port after transmitting the amount of data of the interval, the data packet requested by the response packet is transmitted after the data transmission delay time saved by the saving means has elapsed. Data transmission delay generating means for starting the above may be included.

Further, the above-mentioned traffic means is a data packet transmitted from the data transmission side port of the virtual client port and the virtual server port during the data transmission process and received by the data reception side port through the device and system to be evaluated. , A response transmission delay generation means for transmitting a response packet from the data receiving side port at the time when the response delay time stored in the storage means elapses every time the data amount of the response delay interval stored in the storage means is received. May be included.

In the data transmission process, the traffic means is a data packet transmitted from the data transmission side port of the virtual client port and the virtual server port and received by the data reception side port through the evaluation target device and system. , The window for changing the window size of the response packet transmitted by the data receiving port to the window change size stored in the storing means each time the amount of data in the window value size change interval stored in the storing means is received. Size changing means may be included.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a block diagram of an embodiment of a traffic generator device according to the present invention. In the figure, a TCP traffic generator device 10, which is an embodiment of a traffic generator device, is shown.
Indicates that the virtual client port 11 has a send / receive buffer 12
It is connected to the frame generation / analysis unit 13 via. Further, the frame generation / analysis unit 13 is connected to the state storage unit 15, the timer 16 and the setting storage unit 17 via the frame transmission timing control unit 14. In addition, frame generation,
The analysis unit 13 is connected to the virtual server port 19 via the transmission / reception buffer 18.

The virtual client port 11 and the virtual server port 19 are external ports for a virtual server client and a virtual server, respectively. The transmission / reception buffers 12 and 18 are storage units that temporarily store the processing-waiting frames. The frame generation / analysis unit 13 assembles a transmission frame and analyzes a reception frame. The frame transmission timing control unit 14 includes a state storage unit 15 and a timer 1.
The frame transmission timing is calculated from 6 and each output of the setting storage unit 17.

The state storage unit 15 is a storage unit for storing various parameters other than input parameters, the number of transmitted packets, and calculated values such as the initial value of the retransmission timer. The timer 16 is provided for the frame transmission timing control unit 14 to calculate the transmission timing. The setting storage unit 17 receives input parameters (for example, a destination MAC address (M1
(X)), a destination IP address (I1 (x), etc.).

As shown in FIG. 2, this TCP traffic generator device 10 has a virtual client port 1
1 and the virtual server port 19 are connected to the evaluation target device and the system 20, and the TCP connection (connection and disconnection response confirmation) and the data transfer amount for each TCP connection (window (Window (Window ), Transmission delay) are both simulated at the same time.

As an example of the above evaluation target device and system 20, in FIG. 2, a hub (HUB) 21 which is a concentrator is connected to the virtual client port 11, and a hub 26 which is a concentrator is connected to the virtual server port 19. Further, from the hub 21, the bandwidth control device 22 and the router (Route)
r) 23, the leased line 24 and the router 25 through the hub 2
6 shows the system connected to 6. The routers 23 and 25 perform data (packet) routing by looking at the IP address.

Next, the operation of this embodiment will be described. When the port number of the virtual client port 11 is x, the parameters of the port number x are as follows. The basic parameter is the destination MAC address M1
(X), source MAC address M2 (x), destination IP
Address I1 (x), source IP address I2 (x),
There is a destination TCP port number T1 (x), a source TCP port number T2 (x), a window size WS (x), and a maximum segment size MS (x).

Further, there are a total number of bytes D (x), a data transmission delay interval DDI (x) and a data transmission delay time DDT (x) as data transmission parameters, and an Ack delay interval ADI (x) as a data reception parameter. , Ack delay time ADT (x), window value size change interval WCI
(X) and the window change size WCP (x).

On the other hand, assuming that the port number of the virtual server port 19 is y, there are the following parameters for the port number y. The basic parameters are the destination MAC address M1 (y), the source MAC address M2 (y), the source IP address I2 (y), and the source TCP port number T2.
(Y), the window size WS (y), and the maximum segment size MS (y).

The data transmission parameters include the total number of bytes D (y), the data transmission delay interval DDI (y), and the data transmission delay time DDT (y), and the data reception parameter is the Ack delay interval ADI (y). , Ack delay time ADT (y), window value size change interval WCI
(Y) and the window change size WCP (y).

In this embodiment, by setting these parameters in the setting storage unit 17, under the control of the frame transmission timing control unit 14, the connection process, the data transmission process, and the disconnection process will be described in this order. Running, TCP
Connection (connection, disconnection, response confirmation) and its TCP
Simulate both data transfer amount (window, transmission delay) for each connection at the same time.

[Connecting Process] First, regarding the connecting process, FIG.
The connection process will be described together with the sequence diagram. 2 in FIG.
The same reference numerals are given to the same components as. The TCP traffic generator device 10 transmits a SYN packet from the virtual client port 11 having the port number x (hereinafter referred to as client port x) to the device to be evaluated and the system 20 (step 101). The evaluation target device and the system 20 transfer the input SYN packet as it is to the virtual server port 12 (hereinafter referred to as the server port y) of the port number y of the TCP traffic generator device 10 (step 102).

TCP traffic generator device 10
Receives a SYN packet to server port y,
A (SYN + Ack) packet is transmitted from the server port y to the evaluation target device and the system 20 (step 10).
3). The evaluation target device and system 20 are input (S
The YN + Ack) packet is directly transferred to the client port x of the TCP traffic generator device 10 (step 104).

TCP traffic generator device 10
When receiving the (SYN + Ack) packet to the client port x, the Ack packet is transmitted from the client port x to the device to be evaluated and the system 20 (step 105). The evaluation target device and the system 20 directly transfer the input Ack packet to the server port y of the TCP traffic generator device 10 (step 106). As a result, connection processing is performed.

[Data Transmission from Client Side to Server Side] Next, the operation on the client side in data transmission from the virtual client to the virtual server will be described with reference to the sequence diagrams of FIGS. 4 and 5. The TCP traffic generator device 10 has a client port x
From the device to be evaluated and the system 20, the first (W) of the D (x) bytes divided into MS (y) bytes
The data up to the S (y) / MS (y)) th packet is continuously transmitted (steps 111 to 114). Here, as an example, if WS (y) / MS (y) = 4, the first 4
The packet data of packet eyes D1 to D4 are continuously transmitted. At the time of transmission, a retransmission timer for each packet is started.

Subsequently, when an Ack packet (D5 request) from the server port y is waited for and the client port x receives the Ack packet from the server port y within the retransmission timer (step 115 in FIG. 4), the window of the Ack packet is displayed. Let the size be WS, from packet D5 requested by the Ack packet to (WS (y) / MS
(Y)) = Packet data D5 to D up to the fourth packet
8 are continuously transmitted (steps 116 to 119). Note that packets that have already been transmitted are not transmitted.

Next, when an Ack packet (D9 request) from the server port y is waited for, and the client port x receives the Ack packet from the server port y within the retransmission timer (step 120), the final transmission packet D9.
To the server port y through the device to be evaluated and the system 20 with a push flag attached (step 121). In this Push flag, "1" indicates that there is a flag and "0" indicates that there is no flag. After that, it is transmitted from the Ack packet requesting the next packet D10 from the server port y, and this is transmitted to the evaluation target device and system 20.
The data transmission ends when the client port x is received through (step 122).

Here, for example, if the packet data D4 from the device to be evaluated and the system 20 to the server port y is lost, and the client port x cannot receive the Ack packet from the server port y within the retransmission timer (see FIG. 5). In steps 124 and 125), the TCP traffic generator device 10 retransmits the packet data D4 that could not be transmitted from the client port x (step 126 in FIG. 5).

When the packet data D4 is received at the server port y, the Ack packet (D5
Request) and the client port x receives the Ack packet from the server port y (step 127 in FIG. 5), the window size of the Ack packet is set to WS.
And packet D5 requested by the Ack packet
To (WS (y) / MS (Y)) = the fourth packet data D5 to D8 are continuously transmitted (steps 128 to 131 in FIG. 5). Hereinafter, the same operation as in FIG. 4 is performed.

Next, the operation on the server side when transmitting data from the virtual client to the virtual server will be described with reference to FIGS.
Will be explained together. 6 to 8, the same steps as those in FIGS. 4 and 5 are designated by the same reference numerals, and the description thereof will be omitted.

When transmitting data from the virtual client to the virtual server, the server side waits for data from the client port x, and if continuous data of (WS (y) / MS (y)) packets is received. , Sends an Ack packet requesting the next packet. If non-arrival packets are detected without being consecutive, an Ack packet requesting non-arrival packets is transmitted. Also, Pu
When the data with the sh flag is received, the Ack packet requesting the next packet is immediately transmitted. Hereinafter, the above operation is repeated.

Here, as shown in the sequence diagram of FIG. 6, when the client port x receives an Ack packet after transmitting DDI (x) bytes (step 135) (step 120), the data transmission delay time DDT.
(X) After waiting (step 136), the corresponding data is transmitted (steps 137 to 140). Then DDI
(X) A data delay is generated for each byte transmission. This is to simulate a delay due to waiting for processing on the client side.

Further, as shown in the sequence diagram of FIG. 7, the server port y receives the ADI from the time when the first data is received to the time when the next data is received.
After receiving (y) bytes, wait for the Ack delay time ADT (y) (step 143), and then request the next data A
The ck packet is transmitted (step 144). afterwards,
An Ack transmission delay is generated every ADI (y) byte transmission. This is to simulate the delay due to the processing waiting on the server side.

Further, as shown in the sequence diagram of FIG. 8, the server port y has the window size change interval WCI.
After receiving (y) bytes (step 151), when transmitting an Ack packet requesting the next data, the window size of the Ack packet is changed to WCP (y) and transmitted (step 152). Then the server port y is WCI
(Y) The window size of the Ack packet is changed to WCP (y) for each byte and transmitted to the client side.

In FIG. 8, WS (y) / MS (y) = 4, W
This is an example of CI (y) / MS (y) = 3, and packet D9
After sending an Ack packet requesting the request (step 152),
Three packets D9 to D11 are continuously transmitted from the client port x to the server port y (step 15).
3-155).

[Data Transmission from Server Side to Client Side] Next, regarding the data transmission from the virtual server to the virtual client, the operation on the server side and the client side will be described. First, the operation on the server side will be described with reference to the sequence diagrams of FIGS. 9 and 10. The TCP traffic generator device 10 divides the D (y) bytes from the server port y through the device to be evaluated and the system 20 into MS (x) bytes, which is the first (WS).
The data up to the (x) / MS (x)) packet is continuously transmitted (steps 161 to 164 in FIG. 9). here,
As an example, WS (x) / MS (x) = 4 is set, and the packet data of the first fourth packet D1 to D4 is continuously transmitted. At the time of transmission, a retransmission timer for each packet is started.

Subsequently, the server port y waits for an Ack packet input from the client port x. As shown in the sequence diagram of FIG. 9, when the server port y receives the Ack packet from the client port x before the retransmission timer expires (step 165), the window size of the Ack packet is set to WS and the Ack packet is used. From the requested packet D5 (WS (x) / MS
(X)) Data packets D8 up to the packet th are continuously transmitted (steps 166 to 169). Note that packets that have already been transmitted are not transmitted.

Then, the TCP traffic generator device 10 repeats the above operation until it transmits D (y) bytes from the server port y, and after transmitting D (y) bytes, receives the Ack packet requesting the last packet. Then (Step 170), Pu is added to the last packet D9.
It is sent to the client port x with the sh flag (step 171). An Ack packet requesting the next packet D10 is transmitted from the client port x, and the data transmission ends when the server port y receives this (step 172).

On the other hand, while the server port y is waiting for the input of the Ack packet from the client port x, as shown in the sequence diagram of FIG.
4 is not received at client port x (step 17
5) Therefore, when the server port y cannot receive the Ack packet requesting the next packet from the client port x within the retransmission timer time (step 176), the corresponding packet D4 is retransmitted when the retransmission timer expires. (Step 177). After that, the operations after step 165 described with reference to FIG. 9 are performed.

Next, the operation on the client side when transmitting data from the virtual server to the virtual client will be described with reference to FIG.
~ It demonstrates with FIG. 11 to 13, the same steps as those in FIGS. 9 and 10 are designated by the same reference numerals, and the description thereof will be omitted. When transmitting data from the virtual server to the virtual client, the client port x waits for data from the server port y, and if continuous data of (WS (x) / MS (x)) packets is received, the next Send an Ack packet requesting a packet. If non-arrival packets are detected without being consecutive, an Ack packet requesting non-arrival packets is transmitted. Also, Pu
When the data with the sh flag is received, the Ack packet requesting the next packet is immediately transmitted. Hereinafter, the above operation is repeated.

Here, as shown in the sequence diagram of FIG. 11, when the server port y receives an Ack packet after transmitting DDI (y) bytes (step 181) (step 170), the data transmission delay time DDT ( y) After waiting (step 182), the corresponding data is transmitted (steps 183-186). After that, a data delay is generated each time DDI (y) bytes are transmitted. This is to simulate the delay due to the processing waiting on the server side.

As shown in the sequence diagram of FIG. 12, the client port x receives Ack after the first data reception.
A from sending a packet to receiving the next data
After receiving DI (x) bytes (step 191), after waiting for the Ack delay time ADT (x) (step 192), an Ack packet requesting the next data is transmitted (step 170). After that, A is sent for each ADI (x) byte transmission.
A ck transmission delay occurs. This is to simulate a delay due to waiting for processing on the client side.

Further, as shown in the sequence diagram of FIG. 13, the client port x has a window size change interval W.
After receiving the CI (x) bytes (step 195), when transmitting the Ack packet requesting the next data, the window size of the Ack packet is changed to WCP (x) and transmitted (step 196). After that, the window size of the Ack packet is set to WCP (x) for each WCI (x) byte.
Change to and send.

In FIG. 13, WS (y) / MS (y) = 4,
An example of WCI (y) / MS (y) = 3, packet D
After sending an Ack packet requesting 9 (step 19
6), three packets D9 to D11 are continuously transmitted from the server port y to the client port x (steps 197 to 199).

[Disconnection Processing] Next, the disconnection processing of the present embodiment will be described. First, the disconnection process when the data transmission side is the client will be described with reference to the sequence diagram of FIG. A packet D from the client port x to the server port y through the evaluation target device and the system 20.
After 1 transmission (step 201), Pu is added to the final packet D2.
When the sh flag is added and transmitted (step 202),
The server port y sends an Ack packet requesting the packet D3 next to the received packet D2 to the client port x.
(Step 203).

TCP traffic generator device 10
Ends the data transmission when the client port x receives this Ack packet, and transmits a FIN packet for starting disconnection to the server port y through the evaluation target device and the system 20 (step 204). When the TCP traffic generator device 10 receives the FIN packet from the client port x at the server port y,
The (FIN + Ack) packet is transmitted to the client port x through the device to be evaluated and the system 20 (step 205).

The client port x is (FIN +
When the Ack packet is received, the Ack packet is transmitted to the server port y through the device to be evaluated and the system 20 (step 206). Server port y is this Ac
The disconnection process is completed by receiving k packets.

Next, the disconnection process when the data transmission side is the server will be described with reference to the sequence diagram of FIG.
After transmitting the packet D1 from the server port y to the client port x through the device to be evaluated and the system 20 (step 211), the Push flag is added to the final packet D2 and transmitted (step 212). An Ack packet requesting the next packet D3 is transmitted to the server port y (step 213).

TCP traffic generator device 10
Ends the data transmission when the server port y receives this Ack packet, and transmits a FIN packet for starting disconnection to the client port x through the device to be evaluated and the system 20 (step 214). The TCP traffic generator device 10 has a client port x
Receives a FIN packet from server port y,
The (FIN + Ack) packet is transmitted to the server port y through the evaluation target device and the system 20 (step 2).
15).

The server port y is the above (FIN + Ac
k) When the packet is received, the Ack packet is transmitted to the client port x through the device to be evaluated and the system 20 (step 216). The disconnection process is completed when the client port x receives this Ack packet.

As described above, according to this embodiment, it is possible to perform a simulation in accordance with a series of actual TCP connection flows of connection processing, data transmission processing, and disconnection processing. Also, the data transfer amount (window, transmission delay) for each connection can be simulated.

The TCP traffic generator device 10 is a device for generating TCP traffic.
The evaluation itself of the evaluation target device and the system 20 is determined by the evaluator by setting a standard. Therefore, for example, when a device that does not pass a certain TCP traffic is connected as the evaluation target device, even if the corresponding traffic is passed by the TCP traffic generator device 10, the processing is naturally not completed and the evaluation result is OK. Become.

The present invention is not limited to the above-mentioned embodiment, but at the same time as transmitting TCP traffic, the state of traffic for each port is held, and the statistical value (total number of connections, transmission byte (packet) ) Number, received bytes (packets), retransmitted packets, error packets, average response time, etc.).

[0056]

As described above, according to the present invention,
Since the connection and the data amount for each connection are simulated at the same time, the simulation according to the flow of the connection (connection → data transmission → disconnection),
It is possible to simulate the disturbance of the data transmission amount, and in the flow of a series of connections, the influence of the data amount of each connection and the influence of the disturbance of the data transfer amount due to the buffer state of the receiving terminal of each connection. It is possible to perform a simulation closer to the actual environment, taking into account data due to processing, delay in response packet transmission, etc., and the reliability of the simulation can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a diagram showing a connection example of the device of the present invention with a device to be evaluated and a system.

FIG. 3 is a sequence diagram of an example of connection processing according to the present invention.

FIG. 4 is a sequence diagram for explaining operation on the client side in data transmission from the virtual client to the virtual server according to the present invention.

FIG. 5 is a sequence diagram for explaining the operation on the client side in the data transmission from the virtual client to the virtual server according to the present invention.

FIG. 6 is a sequence diagram for explaining operation on the server side in data transmission from the virtual client to the virtual server according to the present invention.

FIG. 7 is a sequence diagram for explaining operation on the server side in data transmission from the virtual client to the virtual server according to the present invention.

FIG. 8 is a sequence diagram for explaining operation on the server side in data transmission from the virtual client to the virtual server according to the present invention.

FIG. 9 is a sequence diagram for explaining operation on the server side in data transmission from the virtual server to the virtual client according to the present invention.

FIG. 10 is a sequence diagram for explaining operation on the server side in data transmission from the virtual server to the virtual client according to the present invention.

FIG. 11 is a sequence diagram for explaining the operation on the client side in the data transmission from the virtual server to the virtual client according to the present invention.

FIG. 12 is a sequence diagram for explaining operation on the client side in data transmission from the virtual server to the virtual client according to the present invention.

FIG. 13 is a sequence diagram for explaining the operation on the client side in the data transmission from the virtual server to the virtual client according to the present invention.

FIG. 14 is a sequence diagram for explaining disconnection processing when the data transmitting side is a client according to the present invention.

FIG. 15 is a sequence diagram for explaining disconnection processing when the data transmission side is a server according to the present invention.

FIG. 16 is a sequence diagram of an example of an evaluation method by a conventional traffic generator device.

FIG. 17 is an operation sequence diagram of another example of the conventional traffic generator device.

[Explanation of symbols]

10 TCP traffic generator device 11 Virtual client port 12, 18 Send / receive buffer 13 Frame generation and analysis unit 14 Frame transmission timing control unit 15 State storage 16 timers 17 Settings Storage 19 Virtual server port 20 Target devices and systems

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-61-30147 (JP, A) JP-A-63-290432 (JP, A) JP-A-59-43654 (JP, A) JP-A-9- 200209 (JP, A) JP 10-93695 (JP, A) JP 63-63242 (JP, A) JP 11-163916 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04L 12/56 400 H04L 29/14 G06F 13/00 351

Claims (6)

(57) [Claims] 1. A virtual client port connected to an evaluation target device and system, a virtual server port connected to the evaluation target device and system, and a first parameter relating to data and an address transmitted from the virtual client port. And a second regarding data and address transmitted from the virtual server port.
And a storage unit configured to store the parameters of the storage device and the evaluation target device and system between the virtual client port and the virtual server port based on the first and second parameters stored in the storage unit. A connection process for transmitting and responding to a predetermined packet via a data transmission process for transmitting a data packet from one of the virtual client port and the virtual server port to the other;
A traffic generator device comprising: traffic means for sequentially performing a disconnection packet transmission and a disconnection process for responding, and simultaneously simulating a connection and a data amount for each connection. 2. The traffic means receives data even after a predetermined retransmission timer time has elapsed, after transmitting a data packet from a data transmission side port of the virtual client port and the virtual server port during the data transmission process. 2. The traffic generator device according to claim 1, further comprising a resending unit that resends the corresponding data packet from the data transmission side port when a response packet transmitted from the side port is not received by the data transmission side port. . 3. The traffic means, during the data transmission process, starts a data packet transmission from a data transmission side port of the virtual client port and the virtual server port, and then stores a predetermined data in the storage means. When the response packet from the data receiving side port is received at the data transmitting side port after transmitting the data amount of the data transmission delay interval, the response packet is returned after the data transmission delay time stored by the storing means has elapsed. 2. The traffic generator device according to claim 1, further comprising a data transmission delay generating means for starting transmission of a requested data packet. 4. The traffic means, during the data transmission process, transmitted from a data transmission side port of the virtual client port and the virtual server port and received by a data reception side port through the evaluation target device and system. Each time a data packet is received in the response delay interval stored in the storage means, a response packet is transmitted from the data receiving side port when the response delay time stored in the storage means has elapsed. 2. The traffic generator device according to claim 1, further comprising a response transmission delay generating means for performing the response transmission delay. 5. The traffic means, during the data transmission process, transmitted from a data transmission side port of the virtual client port and the virtual server port and received by a data reception side port through the evaluation target device and system. Each time a data packet is received, the window size of the response packet transmitted by the data receiving port is stored in the storage unit every time the data amount of the window value size change interval stored in the storage unit is received. The traffic generator device according to claim 1, further comprising window size changing means for changing the size to a changing size. 6. The traffic generator device according to claim 1, wherein the connection is a TCP connection.