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Network tester



Introduction

With the popularity and complexity of the network, the reasonable establishment and normal operation of the network have become extremely important, and the normal operation of the network must be guaranteed from two aspects. First, the quality of network construction directly affects the subsequent use of the network, so the quality of construction cannot be ignored. It must be strictly required, certification inspections, and preventive measures. Second, the troubleshooting of network faults is very important and directly affects the operating efficiency of the network. High efficiency and short time must be pursued. Therefore, network detection auxiliary equipment is becoming more and more important in network construction and network maintenance.

The use of the network tester can greatly reduce the time it takes for network administrators to troubleshoot network faults, can provide the efficiency of the construction staff of the integrated wiring, and accelerate the progress and quality of the project. This type of equipment has been widely used in foreign countries and is an indispensable tool in the process of network detection and network construction. Compared with foreign countries, the scope of domestic use is still very limited. The main reason is equipment rental and manual replacement, mainly due to domestic users. The awareness of this type of product is not enough, and the sensitivity to network failures is not high. Network tester manufacturers include foreign companies such as Fluke, Agilent and Ideal, as well as domestic companies such as Xinertai, Zhongchuangxintest, and Netur. Among the domestic enterprises, Xinertai's iTester has the most powerful function. This instrument is not only used in large-scale applications in network equipment manufacturing enterprises such as Tongwei, Riscomda, Tenda, Barda, NEC, etc., but also in research institutes such as the Electric Power Research Institute. Place.

Classification

1. According to the network transmission medium, network testers can be divided into wireless network testers and wired network testers.

Wireless network

The wireless network tester mainly detects wireless routers and APs. It can sort out the terminals connected in the wireless network and the wireless signal strength, thereby effectively managing the network In the node, enhance network security. This kind of product technology is not very mature yet. With the promotion of wireless networks, wireless network testers will also receive more and more attention from network management and become an important testing tool.

Wired network

Common transmission media in wired network include: twisted pair, optical fiber and coaxial cable. Coaxial cables are rare, and twisted-pair cables are commonly used. Optical fibers are the development direction of future networks. The network testers developed for transmission media on the market are divided into optical fiber network testers and twisted pair network testers. Optical fiber network testers are not commonly used, so what we usually call network testers refers to twisted pair network Tester.

Second, Network testers can be divided into cable testers, multi-function network testers and network performance testers according to their functions.

Cable tester

Cable tester is mainly for network media detection, including cable length, crosstalk attenuation, signal-to-noise ratio, circuit diagram and cable specifications, etc. Parameters, often used in the construction of integrated wiring.

Multi-function network

Multi-function network tester usually refers to a network testing equipment integrated with multiple test functions, such as integrated link identification, cable search, cable diagnosis, scan line Sequence, topology monitoring, Ping function, port search, POE detection, etc. Because of its complete equipment functions and wide range of applications, this type of equipment is capable of network maintenance, network construction, and cable diagnosis.

Network performance tester

Network performance testing equipment is a high-end equipment, the main functions include network traffic testing, data interception, IP query, traffic analysis, etc., often used in large-scale network security fields, Industry-specific products.

Three. The network tester can be divided into network construction equipment and network maintenance equipment according to its purpose.

Network construction equipment

Network construction equipment mainly refers to the equipment used in the construction of network integrated wiring, emphasizing excellent product quality and accurate measurement data, which can adapt to the construction environment and data requirements .

Network maintenance equipment

Network maintenance equipment pays more attention to the complete functions of the product, multi-purpose, and can deal with various problems in the network. Under normal circumstances, there is no obvious boundary between construction equipment and maintenance equipment, and the selection is mainly based on specific conditions and requirements.

Handheld

Multifunctional network tester is a relatively common network testing tool, it can be said to be a generalist of network testing. Multifunctional network tester is usually defined as a kind of network maintenance Tool, of course, this does not hinder its practicality in engineering. As the name implies, since these products are multi-functional integrated, there is no obvious difference in product grades, and roughly include the following functions:

1, cable diagnosis

Cables and connectors form the basic structure of the local area network. Regardless of the initial deployment of the network or the maintenance of the established network, most of these tasks still need to be completed manually, which brings about the problem of network reliability. At the same time, the aging of cables and various connectors at different locations can also cause network connection failures. When there are other faults in the network such as cable interruption (open circuit) and wrong short-circuit (short circuit) of twisted pair pairs, network communication will be interrupted. The network administrator can quickly diagnose and analyze the connection reliability and connection status of the Ethernet network cable through the TDR (time domain reflection) cable diagnosis function of the network tester, and accurately locate the location of the fault. In the network environment composed of Cat5/Cat5E twisted pair, potential cable faults include:

Open circuit: Lack of continuity between the connectors at both ends of the twisted pair.

Short-circuit: 2 or more wires are short-circuited together.

Cross-pair: The twisted pair is not properly connected at the end. For example, pair 3 is connected to connectors 4 and 5 at one end, and to connectors 7 and 8 at the other end.

Reversed pair: The two wires in the twisted pair are connected with opposite polarities. For example, a wire in pair 3 is connected to connector 1 on one side and to connector 2 on the other side, and the second wire is connected between connector 2 and connector 1.

Incorrect termination: The cable termination impedance is not equal to 100 ohms. Because the typical Category 5 (Cat5) cable impedance is 100 ohms, the cable termination at each end must also be 100 ohms to prevent waveform reflections and potential data errors.

2, POE test

With the development of network technology, many network equipment manufacturers have launched switches based on PowerOverEthernet (POE) Technology to solve the problem of low-power terminal equipment deployment in some network environments where power wiring is more difficult. POE can transmit data signals for some IP-based terminals (such as IP telephones, wireless LAN access points AP, network cameras, etc.) without any changes to the existing Ethernet Cat.5 cabling infrastructure , It can also provide DC power supply for such equipment to ensure the normal operation of the existing network while ensuring the safety of structured wiring, and to minimize costs. The network tester can automatically simulate PD devices of different power levels, obtain the power supply voltage waveform of the PSE device, detect according to different device environments, and draw the voltage waveform output by the PSE power supply on the screen. The network tester can intelligently simulate different power levels of Ethernet powered PD (PowerDevice) devices to detect the availability and performance indicators of PSE (PowerSourcing Equipment), including the power supply type of the device, the available output power level, and the supported power supply standards And the supply voltage.

3. IdentificationPort

In some long-used network environments, there are often When the identification is worn or lost, it is difficult for technicians to determine which port of the switch the IP terminal is connected to when troubleshooting. It often requires repeated investigations to distinguish them. The network tester provides a port flashing function for this situation. By setting its own port status, the LED indicator of the connected switch port is turned off and on at a certain frequency, allowing the administrator to determine the switch corresponding to the remote port at a glance. port.

4. Scanning line sequence

Network testers usually provide twisted-pair cable line sequence scanning function, which graphically displays twisted-pair cable end-to-end Connection line sequence. Check that the end-to-end connection of the twisted wire conforms to the EIA/TIA568 twisted wire standard. This function can replace the wire tester to verify the twisted pair wire sequence.

5. Locate the cable

The network tester can usually be used with audio detectors for cable search in order to find the cable location and fault points.

6. Link identification

Link identification function is mainly used to determine the link rate of Ethernet, 10M, 100M or Gigabit , And this type of equipment can usually determine the working status of the network, half-duplex or full-duplex.

7, Ping

The ping function is very important to the network tester, not only for the detection and diagnosis of the physical layer of the network, but also the network tester itself. An IP terminal can test the connectivity of the network (IP) layer, so that network management and maintenance personnel can, in most cases, test the point of failure to eliminate the fault without carrying a laptop. Extensible PingICMP connectivity test, according to user-defined information, repeat the connectivity and reliability test of the specified IP address.

8. Data management

Data management is usually an additional function to view management work records and conditions. Since the integrated functions of various network testers are slightly different, here are some representative products for users to identify and choose.

Fluke

This is a very representative product. LinkRunnerPro is in the same line as the previous version of LinkRunner. LinkRunner was once a classic. Since the product does not support Gigabit Ethernet, I will not introduce it to you as a typical product. LinkRunnerPro aims to provide a simple and specialized tool for desktop support personnel and network maintenance personnel to solve most common PC users and device connection problems.

Function:

1. Link identification, can judge the network link speed, including 10/100/1G network, and can judge the network half duplex/duplex at the same time Status

2, Ping, ip can be set.

3. POE detection, to verify the availability, voltage level and whether the pair of Ethernet power supply lines meets IEEE802.3af specifications.

4. Identify the port

5. Cable diagnosis, test the wiring diagram and length; detect wrong wiring, short circuit, string Winding pair or open circuit problem; use TDR to measure the distance to the fault point.

6. Locate the cable, use IntelliTone digital audio technology, hub flashing function or optional cable ID to locate the cable in the distribution panel or wall socket.

7. Data management, save link, ping, PoE, security and cable test results to the device, and upload it to the PC via a USB cable.

Nitul

Nitul is the first company in China that focuses on R&D and production of mid-to-high-end network testing equipment. This is a new brand. The nLink-Ex series of products are suitable for domestic users with a brand-new Chinese interface, simple operation method, and high cost performance. Therefore, I will focus on recommending them here. One supports domestic brands and the other provides more choices for users.

Function:

1. Link identification, can judge the network link speed, including 10/100/1G network, and can judge the network half duplex/duplex at the same time Status

2, Ping, ip can be set.

3. Topology detection, the link status of 32 nodes in the real-time network.

4. POE detection, to verify the availability, voltage level, and whether the pair of power over Ethernet cables conform to IEEE802.3af and IEEE802.3at specifications.

5. Identify the port

6. Cable diagnosis, test the wiring diagram and length; detect wrong wiring, short circuit, string Winding pair or open circuit problem; use TDR to measure the distance to the fault point.

7. Scanning line sequence, nLink-Ex can visualize the connection mode and line sequence of the twisted pair through its own port.

8. Data management, save the link, ping, PoE, security and cable test results to the device, and access the PC through the web in the same network segment to read the data .

The common multi-function network tester in the market also includes the LanScaperPRO of Taiyou Company, etc., so I won't repeat it.

Scope of use

LAN management

With the rapid development of the network, the stability and security of the network have become important in enterprises and institutions, and the network administrator’s Responsibilities also increase, and heavy network failures will follow. The network tester is just such a good helper that can solve problems for network administrators.

Comprehensive wiring

In the construction of network wiring, it is a tedious task to detect the connection quality and length of the network cable and the positioning of the network cable port. The network tester can help the construction staff quickly and accurately Make judgments.

Data center

The smoothness of the network of the data center plays an important role, and the network tester can help network maintenance personnel to quickly locate the fault.

Broadband business

User broadband failure is the most troublesome problem for broadband business companies. Whether the failure is quickly resolved and the stable operation of the network directly affects the company’s image and reputation, network tester It is an indispensable tool for technical support personnel.

Network computer room

The computer room breaks down very frequently. Equipping with a network tester can reduce the time for administrators to troubleshoot.

Purchasing instructions

Functional requirements

The network tester is highly integrated. It integrates multiple network function modules. You must have Choose selectively and only sell the features you need. After all, this is not a cheap tool.

Accuracy of measurement

Buy according to your exact requirements, usually the measurement accuracy and price of this kind of products increase in series.

This article is from the network, does not represent the position of this station. Please indicate the origin of reprint
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