Application of chariot, a professional evaluation tool

 

"Why is the network speed so slow ?" I'm afraid this is the most common sentence heard by network administrators. In the face of user complaints, if the connection fails, we can solve the problem through simple troubleshooting. However, it is difficult to solve problems that can be connected but slow, because these problems are mostly related to the network bandwidth or network devices we enjoy, this involves our selection of network service providers and network devices. So how can we clearly understand the bandwidth size and the throughput of the device, so as not to be misled by the data provided by JS?

We need to use professional tools to measure network bandwidth and data throughput. The chariot professional evaluation tool is used to measure the connected bandwidth between any two computers in the network. The software can also display the measurement results in graphs, this allows us to compare, browse, and learn about network bandwidth in a timely manner.

　　Approaching powerful chariot

Running platform: Windows 2000/XP/2003

Hardware requirements: the CPU is pⅲ or above, and there are more than MB in it

Software advantages: through simple configuration, the network connection speed between two computers can be displayed graphically.

This is currently the only widely recognized test software for application-layer IP networks and network devices in the world. It provides end-to-end, multi-operating systems, multi-protocol testing, and multi-application simulation testing, applications include wired networks, wireless networks, wide area networks, and various network devices. You can locate network faults, analyze user complaints, evaluate the system, and optimize the network. You can test network or network parameters (throughput, response time, latency, jitter, packet loss, etc.) from the user's perspective ).

Chariot is essentially different from general network management systems and some online monitoring systems. The Network Management System and online monitoring system adopt passive monitoring, while chariot adopts active monitoring and measurement. The network management system and online monitoring system provide qualitative measurement, while chariot adopts quantitative measurement.

Chariot generates and simulates real traffic, and uses the end to end method to test the performance of network devices or systems in the real environment. It can be widely used in vswitches, vrouters, wired networks, wireless networks, VoIP, and other high-tech technologies to measure the functions and performance of these networks.

The basic components of this software include the chariot console and endpoint. The chariot console is mainly responsible for monitoring and statistics, and the endpoint is responsible for traffic testing. In actual operations, the endpoint executes the script commands released on the chariot console, to complete the required test (the specific workflow is shown in Figure 1 ).

Figure 1

: Http://hack.bji.cn/chariot.rar

　　Test bandwidth

Do you want to know the bandwidth of your network? Do you want to know how much your network bandwidth is consuming? Today, we use several examples to let everyone use chariot and measure what they want to know. Only the measured network bandwidth is the actual bandwidth we enjoy on a daily basis. Do not blindly trust the bandwidth promised by the network service provider, or simply agree with the comments of JS on network products.

　　Instance 1: measure the bandwidth between any two nodes in the network.

Task Description: some people in the LAN often reflect the slow network speed. How can we determine the connection speed of the two computers in the network? If you use sniffer, you can only capture packets, but cannot provide the actual bandwidth. Chariot is required to help you in this case. Suppose we want to measure the actual bandwidth between computer A 10.91.30.45 and computer B 10.91.30.42.

To solve the problem: users in the LAN often feel slow mutual access. In this case, we can use chariot to view network connection information.

Step 1: first run the chariot client software endpoint on computer A and computer B. After endpoint.exe is run, a process named endpoint is added to the task manager.

Step 2: the machine to be measured is ready. In this case, you need to run chariot on the control side. You can select another computer on the network, you can also run chariot directly on computer A or computer B (figure 2 ).

Figure 2

Step 3: click "new" on the main interface, and then click "add pair ".

Step 4: Enter the pair name in the "add an endpoint pair" window, enter the IP address 10.91.30.45 of computer A at endpoint1, and enter the IP address 10.91.30.42 of computer B at endpoint2. Press the select script button and select a script. Because we are measuring the bandwidth, you can select the built-in throughput. scr script (Figure 3 ).

Figure 3

Tip: chariot can measure multiple network transport layer protocols, including TCP, UDP, and SPX. You can select the default TCP protocol when measuring bandwidth.

Step 5: click "run" in the main menu to start the measurement.

Step 6: The software will test the situation where 100 packets are sent from computer A to computer B. Since the default data packet transmitted by the software is very small, the measurement will soon end. Click throughput in the result to view the bandwidth of the measurement. Figure 4 shows that the actual maximum bandwidth between computer A and computer B is 83.6 Mbps.

Figure 4

Due to the loss of switches and network cables, the actual bandwidth is usually less than 100 Mbps. Therefore, the 83.6mbps in this example basically indicates that the maximum bandwidth between computer A and computer B is 100 Mbps, the loss can reach a transmission rate of more than 80 Mbps.

Example 2: courtesy exchange, one-time measurement of two directions

Task Description: instance 1 introduces the one-way measurement method, that is, only the bandwidth between A and B is detected. However, in actual work, the network is a single or duplex operation, which is also the main factor affecting the network speed. Therefore, we should try to establish bidirectional pair instead of unidirectional pair when using chariot for measurement, the measurement result shows the speed from A to B and the speed from B to.

To solve the problem: the transmission speed from A to B is very fast, but the speed from B to a is very slow, especially when a and B copy files from the other computer to the local machine at the same time.

Step 1: first run the chariot client software endpoint on computer A and computer B.

Step 2: the machine to be measured is ready. In this case, you need to run chariot on the control side and directly run chariot on computer A or computer B.

Tip: to ensure successful measurement, you must disable the firewall on computer A and computer B.

Step 3: click "new" on the main interface, and then click "add pair ".

Step 4: Enter the pair name in the "add an endpoint pair" window, enter the IP address 10.91.30.45 of computer A at endpoint1, and enter the IP address 10.91.30.42 of computer B at endpoint2. Press the select script button and select a script. Because the bandwidth is measured, select the built-in throughput. scr script.

Step 5: now we have established a unidirectional measurement from A to B. To measure the two-way network throughput, you must add a one-way measurement from B to A. The result shows two-way data. In the same way as step 4, enter the IP address 10.91.30.42 of computer B at endpoint1, enter the IP address 10.91.30.45 of computer A at endpoint2, and select the throughput. scr script.

Step 6: Now the two pair pairs have been created (Figure 5). Click "run" in the main menu to start the measurement.

Figure 5

Step 7: The software sends 100 data packets from computer A to computer B, and also measures the situation where 100 data packets are sent from computer B to computer. Click the "throughput" tab on the results page to view the bandwidth of the measurement. 6. in the chart below, the green curve represents the value of bandwidth Detection 2, while the red curve represents the value of bandwidth Detection 1, from this figure, we can see that the bandwidth from A to B is larger than that from B to. The above speed also shows that the average bandwidth from A to B is 72 Mbps, while the bandwidth from B to a is only 42 Mbps.

Figure 6

What does this mean? Using chariot to measure the two-way bandwidth between A and B, we can conclude that the bandwidth between A and B is 100 Mbps (the actual bandwidth to remove losses is 72 Mbps ), the bandwidth from B to a is only 50 Mbps. At this point, we should check the network connection device, especially the network cable. It is likely that the speed between B and A is not Mbps but 50 Mbps because of a problem in the network cable production.

TIPS: What is a ticket? What is duplex?

Generally, the network devices we use are both Duplex. That is to say, the transmission from A to B and from B to a can be completed at the same time. A ticket can only transmit data in one direction at a time, either from A to B or from B to. Therefore, the network is in the single or duplex status, and the speed varies greatly.

Example 3: scientific measurement reduces the error

Task Description: when the network is unstable and the speed fluctuates frequently, there are some uncertainties in the measurement speed at a certain time point. How can we minimize the error? We can use scientific measurement to solve this problem, that is, the average method. Aggregate all the measurements together to obtain results closer to the actual values.

To solve the problem: the network transmission speed is very unstable. It usually takes a dozen Mb/s while only a few Mb/s.

Step 1: Install chariot and install the client endpoint on computer A and computer B as mentioned above. Start chariot and click "new.

Step 2: click "add pair" to create a new endpoint pair. Enter the pair name, enter the IP address 10.91.30.45 of computer A at endpoint1, and enter the IP address 10.91.30.42 of computer B at endpoint2. Press the select script button to select the throughput. scr script.

Step 3: Right-click pair 1 and select copy to copy the measurement item (figure 7), and then paste nine such measurement items (figure 8) consecutively ).

Figure 7

Figure 8

Step 4: click "run" to start the measurement. On the throughput tab, we can see that each bandwidth measurement value is about 10 Mbps, in the sum, we can see that the final result is 94 Mbps, which is basically close to the actual value of Mbps.

In reality, there are often unstable factors in the network connection speed. For example, bandwidth exceptions may occur at one time due to broadcast packets or other reasons, and the speed returns to normal at another time. In this case of bandwidth instability, we can use multiple measurements to reduce the error to a certain extent, making our measurement results more effective and accurate.

Example 4: big package Measurement

Task Description: although we can reduce the error through scientific measurement, because the default data packet is only kb, the total data measurement is relatively small. When the bandwidth is relatively large, for example, when the transmission speed provided by a network of more than Mbps or ISP is fast, the results obtained by using KB data packets are not accurate. In this case, you need to modify the size of the default data packet to make the measurement result more accurate.

To solve the problem, the network bandwidth is relatively large or the error is too large when chariot is set by default.

In this instance, most of the steps are basically the same as those described above, so here only describes how to modify data packets. After setting up the measurement pair and selecting the throughput. scr script, click the "edit this script" button. Modify the value of file_size at the bottom of the pop-up window (figure 9) to the expected value. In this way, the data packet with the configured size will be used for transmission during bandwidth measurement. Setting the packet size based on the actual environment makes our results more accurate.

Figure 9

In fact, we can not only edit the size of the sent data packet, but also use the "edit this script" button to write our own scripts. However, we need to have a certain understanding of the scripting language. In addition, the software not only provides a script for throughput. scr, but also has many built-in scripts, such as FTP, HTTP, and IPTV. You can choose based on your actual measurement needs.

　　Example 5: Wireless Network Measurement

Task Description: The above four examples describe how to measure the network bandwidth in a wired network environment. In fact, the most uncertain and desired bandwidth in actual use is the number of wireless networks, after all, data is transmitted wirelessly, which makes measurement more difficult. We are excited that chariot can be used to measure the bandwidth of wireless networks.

To solve the problem, measure the transmission speed of the self-built wireless network, or test the performance of wireless devices of different models and different prices.

The techniques and steps for measuring the bandwidth of a wireless network using chariot are the same as those in the above four examples. It is easy to use. You can use chariot to measure the connection speed between two computers in the wireless network, so as to understand and compare the performance of different types of wireless routers, and finally select a Wireless Router Based on the measurement results. Of course, readers who have already purchased wireless routers can occasionally use chariot to measure their wireless network bandwidth status, understand the current network status, and identify potential risks in a timely manner.

For the network, bandwidth and speed are just like money. We cannot blindly select network devices and be deceived by JS lie. We cannot pay the fees for the ISP to rent the network. With chariot, we can select the best-performing devices. With chariot, we can use networks more clearly and clearly. With chariot, we can truly achieve "Network width and width ".