After the network cable is connected to the switch, the network is blocked and the packet loss is serious. The network cable is directly connected to the computer. What is the reason?

There are three reasons for this phenomenon: first, the operator's responsibility (transmission and switching network failure): the operator must ensure that the signal quality (bandwidth, bit error rate, signal-to-noise ratio, transmission rate, signal level, input-output impedance, signal stability, input-output impedance stability) to users meets national standards; Telephone number: Telecom 10000 Netcom 10060 Tietong 10050 2: Website problem: 1: The website server is unstable; 2. The software of the website is unstable; 3. The quality level of website operation and maintenance is low; Failure to troubleshoot in time; For example, other websites are very good, but one website is particularly poor. This is the problem of the website itself, which has nothing to do with operators and users. ★ Copyright statement: This answer is original and harmonious, and no one can steal it! ★ 3: User (Responsibility) The following factors will lead to your current state. If the above operators have no problems after testing, then it is your users' own problems; If you don't have the following questions, you can call the operator directly and ask the operator to give you the relevant matters of the operator. ★ Copyright statement: This answer is original and harmonious, and no one can steal it! ★ On the premise that the user's equipment settings must be correct, provide the user with the reasons and solutions for this phenomenon: 1: power supply 1. 1 Check whether the power supply is stable with a multimeter? 1.2 Is the AC voltage fluctuation within the allowable range? Does it exceed 5% of the rated voltage? Is the ripple coefficient after 1.3A/D power conversion (checked by millivolt meter) qualified? 1.4 Is the temperature rise of the power supply abnormal? Does the voltage stabilizing characteristic of 1.5 meet the technical index? 1.6 under rated load 1.5, do the voltage stabilization characteristics and ripple coefficient meet the technical indicators? 1.7 When replacing the large fan, does your power supply capacity meet the requirements? 1.8 power supply for general auxiliary equipment (routers, network switches, cats, etc.). ) is a rectifier power supply, with no voltage stabilizing function, large ripple coefficient (possibly due to dry filter capacitor) and poor load capacity; The equipment cannot work due to fever, so special attention should be paid to monitoring during operation. 1.9 Due to overvoltage of equipment (like feeding children, it is more likely to die), low voltage (like feeding children, lack of which will lead to malnutrition), excessive voltage fluctuation (like feeding children, hungry), overcurrent and fever, the overheating protection action will be cut off, and the equipment will not run (that is, it will be slow, delayed and not run)/kloc-0. Are you agile? Refuse to move or misoperation? ★ Copyright statement: This answer is original and harmonious, and no one can steal it! ★2: Check the network cable and the crystal connector (R45): 2. 1 Are the crystal connector and socket plugged in (loose)? 2.2 contact? What is the contact resistance? 2.3 Is there dust? Is it oxidized? 2.4 Are the mechanical locks of the crystal head and seat locked? 2.5 Is the locking firm? 2.6 Are the cable and the crystal head pressed tightly and in good contact? 2.7 The insulation resistance between network cables (using 100V shaking table) should be greater than 20 megohms. ★ Copyright statement: This answer is original and harmonious, and no one can steal it! ★3: Lightning protection and grounding: grounding is mainly to ensure the safety of people and equipment! Lightning will burn the network card; In severe cases, it can cause fire and casualties! Multi-point grounding, repeated grounding and nearby grounding are the principles; Grounding is divided into protective grounding, shielding grounding and working grounding. Static electricity is the chief culprit of blue screen of death! I tested with a noise meter, and the noise voltage without grounding is more than 6000 times larger than the signal. Can your equipment work under such high noise if it is not grounded? Grounding is the most basic requirement, especially for analog devices and digital circuits. Grounding can reduce or eliminate interference from all sides, external interference and inter-line coupling between local and local wiring. Do a good job in grounding shielding of equipment. A lot of interference comes from poor shielding and grounding. Many people only do software, and many interferences are caused by poor grounding or no grounding. This kind of fault is very easy to happen and is easily overlooked by many people. Many equipment damages are directly related to grounding. Ungrounding or poor grounding will lead to intersymbol interference, error code, delay, packet loss, interruption, disconnection (disconnection, interruption), crash, jamming, automatic shutdown, repeated startup, repeated restart (or repeated connection) and other phenomena. Grounding must have more than two grounding electrodes, and the interval between each grounding electrode should be at least10m. There should be no joint between the grounding electrode and the grounding wire of the machine room. Soft copper wire with a cross section of not less than 25mm2 should be introduced into the bus bar of the machine room (no joint is allowed in the middle). The grounding wire should be symmetrically connected with Faraday net to facilitate shunt and scattering. The connection point with the bus should be coated with silver powder conductive paste, and the cross section of the grounding wire from each device to the bus (independent) should not be less than 4m2. Check the grounding instrument at least twice a year (measured with a grounding instrument of class 2.5 or above, and the instrument is in the inspection period). When checking the grounding electrode, it is strictly prohibited to do it in thunderstorm weather. It is forbidden to use the N zero line of water pipes and power lines as grounding; I.e. an independent grounding device. The wires of each equipment are independently connected to the bus bar of the machine room, and it is forbidden to connect the bus bar after series connection. I can say subjectively: whether you are an individual user or a collective user of a large computer room, you are not grounded at all (or the grounding gas is unqualified). ★ Copyright statement: This answer is original and harmonious, and no one can steal it! ★4: Bandwidth: The bandwidth from operators to users is very important. Without enough bandwidth, enough data traffic cannot be guaranteed; Computers can't surf the Internet smoothly; The bandwidth mentioned above refers to the bandwidth of the whole journey, which is as wide as that on the expressway, and there can be no ups and downs in the whole journey; A slight fluctuation in the whole process will affect the network speed; Users have the right to ask operators (tested with frequency scanners) to give protection; ★ Copyright statement: This answer is original and harmonious, and no one can steal it! ★5: Signal-to-clutter ratio: (Signal-to-noise ratio can be understood as signal purity) When the signal is small, the useful signal is covered by noisy stray signals (especially intersymbol interference between symbols), so that the receiving path cannot correctly extract the useful signal from the noisy signal, and the decision circuit cannot correctly judge the symbols, resulting in serious error code and error code loss, which is the reason for the delay. Serious delay will mean disconnection (which will cause slowness, delay, repeated startup, disconnection, delay, disconnection, interruption, disconnection, automatic shutdown, collapse, etc.). ). Use a noise meter or level meter to measure whether the noise level is within the allowable range, or use an oscilloscope to observe whether there are stray signals? Is there intersymbol interference? Take measures to eliminate. Signal-to-clutter ratio is also greater than 60dB. Test (observe) with frequency scanner and oscilloscope. This indicator is to ensure smooth roads. With such a wide road, the whole journey is barrier-free. ★ Copyright statement: This answer is original and harmonious, and no one can steal it! ★6: Matching: Matching includes level matching and impedance matching (tested by level meter and signal generator). 6. 1 level matching: the received signal cannot be too low. If it is too low, it will not reach the threshold level amplitude required by the receiving path, and the equipment will not work normally; If the level is too high, the front-end circuit of the receiving path will be saturated or burned out. The fluctuation of reception level near the reception threshold will make the computer restart frequently and repeatedly; Therefore, receiving level adjustment is very important. During the operation, the liquid level gauge or oscilloscope should be often used to monitor and adjust the receiving level at the joint within an appropriate amplitude range. According to the instructions, use a spirit level to monitor the adjustment. 6.2: Impedance matching: The connection point must match the relative impedance. The mismatch of input and output impedance will lead to reflection attenuation, and the signal will not work normally no matter how strong it is. ★ Copyright statement: This answer is original and harmonious, and no one can steal it! ★7: Optimize the network structure. When people turn on the computer to surf the Internet, they will produce garbage like eating. If they don't wipe the table, wash the dishes and clean the cooker, the computer will gradually show some faults such as slowness, jamming, delay, repeated startup and disconnection. So I personally recommend using some gadgets: such as super rabbit, optimization master, master Lu or 360; Develop a good habit of cleaning up the garbage before going offline. 7. 1: Clean up the garbage fragments and IE cache generated by surfing the Internet in time: as long as you use a computer, you will generate garbage. If it is not cleaned up in time, it will accumulate more and more. If it is not cleaned for a long time, the space for running disk C will become smaller and smaller, more and more chaotic, and finally it will gradually slow down until it collapses; Therefore, arranging and running the C disk regularly can keep the running speed of the computer.

7.2: Synchronize ADSL equipment first: restart the equipment after power failure. ★ Copyright statement: This answer is original and harmonious, and no one can steal it! ★8: Software Settings and Configuration 8. 1: Try to download commonly used software from official website to avoid installing 3. Irregular software, P2P (resource-consuming) software and infrequent software. Close all unnecessary network connections and startup items, such as thunder, BT, donkey, etc. Don't put the software that doesn't run in the running C disk; Update patches in real time. Game software should be downloaded from regular large websites. Pay attention to whether the software is stable. Immature and unstable software will lead to slow, stuck, crash and other failures, especially some popular game software. Some netizens reacted strongly to this. Pay special attention to this kind of software, or delete it immediately. When downloading software, pay attention to the security of rogue software inserted into key computers and remove it at any time. Many acceleration software mostly contains viruses or advertising plug-ins, which take up the resources of your disk. Some game software will directly t-drop the game after starting, and will be disconnected and restarted indefinitely after coming up. Protocol: the protocol in the network should also match it. Mismatching will also cause some equipment failures. Software conflicts can also cause problems such as delay, jam, slowness, crash, disconnection and interruption. 8.2: Anti-virus software and firewall must have at least one valid genuine anti-virus software, and the virus database should be upgraded frequently: firewall settings should be appropriate (not too much, not too high, not too low), which will cause some web pages to fail to open; Viruses can slow down, crash, disconnect, get stuck, restart and shut down computers repeatedly. ★ Copyright statement: This answer is original and harmonious, and no one can steal it! ★9: Temperature, humidity and temperature rise: With the extension of startup time, the temperature of the main equipment and its auxiliary equipment (cats, routers, network switches, etc.). ) will gradually increase. If it can't be released quickly, it will delay-slow-disconnect-collapse. 9. 1: Humidity: In rainy or rainy days and areas with high humidity, the insulation between lines and equipment is reduced, and the signal level is reduced, resulting in intersymbol interference, error code, delay, packet loss, interruption, disconnection (short line or interruption), crash, automatic shutdown, repeated startup (repeated connection) and other phenomena of the computer, or unstable work. Humidity will accelerate oxidation, resulting in transmission interruption. 9.2: Temperature (with the arrival of beginning of autumn, the failure caused by early high temperature will gradually decrease): From the start of the machine, the temperature will gradually increase, and when the temperature rises to a certain extent, it will stabilize at this value, and the difference between this value and the ambient temperature cannot be greater than 25 degrees; Because the computer is a semiconductor device, the actual temperature of the device is required not to be higher than 85 degrees; When the chip temperature is close to 80 degrees, measures should be taken to reduce the working environment temperature of cats, routers, network switches and computer equipment. If it is beyond this range, the computer will appear inter-symbol interference, error code, delay, packet loss, interruption, disconnection (disconnection or interruption), crash, automatic shutdown, repeated startup (frequent connection) and so on. ★ Copyright statement: This answer is original and harmonious, and no one can steal it! ★9.3: The temperature rise (the difference between the actual temperature of the equipment and the ambient temperature is called the temperature rise) is less than 25 degrees Celsius, which has great influence on the normal operation of the equipment, especially when the temperature rise of network switches, routers, computer motherboard chips and network cards is large, the equipment will not be able to operate; Especially for portable (also called notebook) computers, because the design gives priority to size, the temperature rise is difficult to dissipate, and the phenomena such as intersymbol interference, error code, delay, packet loss, interruption, disconnection (short line or interruption), crash, automatic shutdown and repeated startup (repeated connection) caused by temperature rise are most likely to occur. The measures are as follows: a, place equipment (refer to Hubble, cat, router, network switch, computer, etc.). In a safe place for people, disconnect the power supply first, then open the box cover of the equipment, and use air convection to strengthen contact with the air for natural heat dissipation;

B: Install a micro fan on the equipment to increase air convection and carry out forced heat dissipation;

C: If you are inside, I suggest you add a heat sink to the heating part of the equipment after disconnecting the power supply.

D: After the equipment is disconnected from the power supply, drill more holes up and down the equipment with a 3mm drill bit to strengthen air convection and improve heat dissipation conditions; E: For the equipment in ventilated and dry places, it is best to make an insulating heat dissipation bracket (also available in notebooks on the market) to support the natural heat dissipation of the equipment; F: After the computer is used for a long time, the silica gel between the CPU and the heat sink dries up, and the CPU will generate serious heat, resulting in packet loss, delay, slowness, repeated startup, disconnection, automatic shutdown and crash. Re-coating silica gel can restore normal use.

G: Clean up the garbage fragments and IE cache generated by surfing the Internet in time: As long as you use a computer, you will generate garbage. If it is not cleaned up in time, it will accumulate more and more. If it is not cleaned for a long time, the space for running disk C will become smaller and smaller, more and more chaotic, and finally it will gradually slow down until it collapses; Therefore, arranging and running the C disk regularly can keep the running speed of the computer.

H: synchronize ADSL equipment first: turn off the power supply of the equipment and restart the equipment. Users who frequently surf the Internet should open the equipment shell after power failure for half a year at most (by the way, check whether the internal connection of the equipment is good, whether the memory stick is loose, and whether the contact between the memory stick and the card slot is good? Is the plug-in loose? Is it tight? Whether the connection point is firm and the contact is good), clean the dust inside the equipment. 10: wiring: the wiring process is based on the principle of minimum interference; Wiring should be neat and beautiful, strong and weak signals should be separated, and high and low frequency signals should be separated. Improper wiring causes interference such as line coupling and crosstalk, and the line cannot be wound. It is best to use shielded wire (the shielding layer is reliable and grounded). These parasitic interferences will reduce the signal-to-noise ratio of the computer, making it unable to identify useful signals, leading to intersymbol interference, error code, delay, packet loss, discontinuity, dropped line (short line or interrupt) and crash. ★ Copyright statement: This answer is original and harmonious, and no one can steal it! ★ 1 1: The button cell of the motherboard has insufficient or dead power, so it can't start or cause other faults. 12: ADSL users: Multiplex the computer signal with the telephone line, and pay attention to the influence of off-hook, on-hook and ringing on the computer; Because computer and telephone signals are transmitted (multiplexed) on telephone lines, a certain degree of isolation (greater than 60dB) and a certain degree of defense (greater than 60dbB, the better) must be provided between them, especially some nonstandard words may affect the use of computers. 13: timed failure: when the equipment fails at a fixed time, it is necessary to carefully check whether there are large factories around and between the transmission paths, or whether there are electrical equipment, welding and other start-up equipment with a fixed time. 14: The better solution to the slow speed of Win 7 should be as follows: Go to Windows7 Control Panel, find and open color management. In the color management dialog box that opens, switch to the Advanced tab, and then click Change System Defaults in the lower left corner. After that, the color management-system default dialog box will pop up again. In this dialog box, also switch to advanced options, and then uncheck Use Windows Monitor Calibration by default? After modification, save the settings and exit. In theory, it is very slim to use any software to improve your internet speed. It is difficult for us to observe that using any software can improve the network speed. This software only installs some advertising spam plug-ins in your system, which has little effect on improving the network speed. In fact, you can't feel it. Generally, it is a tool for adding advertisements. Not only can't improve your speed, but it will slow you down unconsciously; It's no exaggeration to say it's a virus! ★ Copyright statement: This answer is original and harmonious, and no one can steal it! ★ 15: users who use wireless transmission (mobile phone or wireless network card, wireless router, etc.). ) surfing the Internet is greatly influenced by the field strength of the receiving point (geographical location), and is also limited by the transmission bandwidth and receiving geographical environment: the standing wave coefficient (1.2 is appropriate) of its own position and its own antenna has a great influence on the receiving level, and it cannot be expressed only by signals (possibly the superposition of reflected signals). The larger the antenna gain, the larger the antenna size and the stronger the directivity. Users should always pay attention. ★ Copyright statement: This answer is original and harmonious, and no one can steal it! ★ 16: Multi-machine (protocol interface) * * * Internet access problem: in order to ensure Internet access security; According to the "Regulations on Protecting Internet Security" issued by the Ministry of Public Security, operators have one account and one terminal to facilitate the security monitoring of the Internet; When an account has multiple terminals: relevant certificates of relevant terminal users must be issued and carefully registered and filed; For the network security department to monitor, monitor, supervise and monitor the network security; Prevent criminals from using the Internet to commit crimes or destroy the Internet! Always crack down on criminal activities using the internet! It is the user's obligation to cooperate with this work! ★ Copyright statement: This answer is "Harmony" original, and no one can steal it! ★ From the technical point of view: with the technical measures such as routers, dual network cards and network switches, one account can be accessed by multiple computers, and there is absolutely no technical problem; For the sake of network security, we should still be law-abiding citizens and surf the Internet reasonably, reasonably and legally. Contribute to the maintenance of a harmonious society! If you need to use more than one account to surf the Internet, you should register with the relevant departments in detail; Unrecorded: the operator uses network monitoring software to carry out real-time detection according to law; And take corresponding (restrictive measures such as page notification and forced disconnection) alarm measures for users according to law, and Concord requires users to go through corresponding (one terminal, one account) procedures; Multiple terminals of an account must go through corresponding procedures according to law and put on record carefully. However, some operators implement this regulation for economic benefits, and some operators are not so strict in order to retain customers. Please consult your local operator for details. ★ Copyright statement: This answer is "Harmony" original, and no one can steal it! ★ As long as you follow the above seriously and always insist on doing it, the general configuration and playing mid-range games are quite smooth; Otherwise: no matter how high the configuration is, it will also cause frequent failures; The key depends on who uses it; For people with high quality, the configuration is lower and equally smooth; People with low quality, no matter how high the configuration, also have frequent failures; Dress like a man (sketch: Peisi Chen among the good guys and bad guys: No matter how good clothes you give him, he won't be up to grade! ), clothes are not in high and low grades, just clean. Only those who are not afraid of difficulties and obstacles can hope to reach the other side of the ideal! Thank you for taking my answer!

Thank you: friends! ..-.,.\../..； ....