must be exactly the same as that of the optical cable. Otherwise, the connectivity will fail. In addition, the types of fiber-optic ports connected to each other must be identical,
Or both are Multimode Optical Fiber ports or single-mode optical fiber ports. One end is a Multimode Optical Fiber port, while the other end is a single-mode optical fiber port, which cannot be connected together.
3. transmission rate and duplex mode
Unlike 1000Base-T, 1000Base-SX, 1000Base-LX/LH, and 1000Ba
Smart cabling does not change the basis of the structured cabling system. It should be a general 4-wire Cabling System Based on RJ45, but additional features are added to the communication room. The difference between smart cabling and traditional structured cabling systems is that it allows you to view jumper connections. To receive this information, you must somehow sense or record whether there is a jumper connection. Ideally, this should be automa
The Smart Home cabling system is the basis of the Smart Home System and the channel for its transmission. Next let's take a look at the cable types and common problems in smart home.
Smart Home cable type
1. twisted pair (twisted-pair ). Twisted Pair wires are the most common transmission medium. They are composed of two copper wires that are insulated from each other and have a typical diameter of 1mm. The two wires are twisted together to prevent the electromagnetic induction from generating i
protocol runs on top of the UDP protocol, using the port number 53.Default gateway : Configure the default gateway to create a default path in the IP routing table. A single host can have multiple gateways. The default gateway means that if a host cannot find an available gateway, it sends the packet to the default designated gateway, which handles the packet.Note: The default gateway for a computer cannot be specified casually and must be specified correctly, or a computer will send the packet
In an Ethernet device, a network transformer is added in the middle when the PHY is connected to RJ45. Some transformer centers are routed to the ground. In addition, when the power supply is connected, the power supply value can be different, 3.3 V, 2.5 V, 1.8v all have.
The role of this transformer is analyzed as follows:
1. Why is there some power supply in the middle head? Some grounding? This is mainly determined by the use of the PHY chip UTP
1, Charging pile network realization function1) IC card system networking, security encryption;2) The working environment of the charging pile (temperature, humidity, etc.), working condition detection, alarm, remote maintenance, monitoring;3) Connect the charging station printer, print the consumption credentials;4) Dynamic query of the current available charging pile position;5) LED remote ad delivery function;6) as a WiFi base station, help to improve wireless coverage area, convenient for us
same time, it can be said that two birds in one fell swoop. The machine's external engineering plastic spray silver Matt paint, the internal is black, slightly sand texture, I think the appearance of t2000d5b is not t2000d5 full black so sedated. The appearance of the machine can only be regarded as normal. The joints of the mold are relatively fine, but there is a large gap between the four USB ports, and it is easy to become a place where dust is accumulated.
Port Layout
Most of the ports of
system, monitoring system, background music, access control system, cable TV, lightning protection, and grounding.In a building, it not only includes water, electricity, gas, ventilation, and other essential parts of life, but also shows more intelligence in the weak current system. The Integrated Wiring System and monitoring system, background music, access control system, and cable TV are all part of the Weak Current System. They share common characteristics. Some students who have just start
the data transmitted over the network is normal on the PC end, it is necessary to use the packet capture tool. We recommend Wireshark, a packet capture tool. You can easily view network data packets, which are used to calculate the transmission speed and view the data packet content.
(2) Common commands: Some commands in PC dos, such as ping and telnet commands, are used to check whether the network is smooth and remote logon.
Iii. Network R D based on lower computer
3.1 Hardware Desi
Array allocates space for the Data Segment during system initialization.If the array size is not clear, the data segment cannot allocate space for it, because other data needs to be allocated space in the data segment. When creating a function call stack, the local variable array must also specify the size of the array, because local variables allocate space at the bottom of the stack, if the array size is unknown, the subsequent growth of the stack will not know where to start. Generally, this
labeled with "3". The outer protection rubber of five types of twisted pair wires is thick, CAT 5 is marked on the rubber cover, and "5" is marked on the outer packing cart. The price is higher than that of Category 5 twisted pair wires, which are unshielded twisted pair wires. Compared with common category 5 twisted pair wires, category 5 twisted pair wires have lower attenuation and stronger anti-interference capability when transmitting signals. In a 1/4 M network, the interference degree of
transmission media, and electrical equality are different. The following describes the most commonly used Ethernet NIC.
Ethernet adopts CSMA/CD (carrier-based multi-channel access/conflict detection) control technology. He mainly defines how the physical layer and data link layer work. The data link layer and the physical layer implement their own functions, so they do not care about how the other party operates. There are standard interfaces (such as MII and gmii) between the two to transmit d
Uses external hosts to penetrate the local network firewall, and hosts to penetrate the Network Firewall
This article mainly records a method to penetrate the local firewall, that is, reverse connection. I will write this article while studying and practicing it. The process may not be the most concise, but it only serves as a reference for myself and future generations.
What I need to achieve:
Host A used by the author. In Lan A, the author does not have the management permission of lan a, and
Many people (including the author) think that 10 Base-T 10 m networks use four of the eight signal lines in the network cable, the 100 Base-t m uses all eight signal lines (or how fast ?). However, when the author recently used a 10 m direct connection method (switching between 1 and 3, 2 and 6, and shielding the other four lines) to connect the network cable, unexpectedly, it was found that the Network was being transmitted at a speed of MB, so I had to worry about it. So I checked a lot of inf
RJ-45 plug is a plastic connector that can only be inserted along a fixed direction and automatically prevent shedding, commonly known as "crystal head", terminology for RJ-45 connectors (RJ-45 is a specification for network interfaces, there is also a similar RJ-11 interface, is our usual "telephone interface", used to connect the telephone line ). It is called the "crystal head" because its appearance is crystal clear. This RJ-45 plug must be installed at both ends of the twisted pair to Facil
1. Connect Network
In the WiFi network, find the "meizu-xxxx (typically four-bit MAC address)" Hotspot and connect.
2. Log in and set up the network
Web End settings: In the mobile browser or computer Browser input "192.168.232.1", using the default account, password (all admin) login;
App-side settings: Focus on the Charm family smart home Micro-letter public number (ID:MZSZ01), through the menu options, "My Charm home-> The Phantom router app" can access t
to create a WiFi hotspot, enter the password to connect to the wireless internet
6, the Millet box enhanced version has no network cable interface (standard version has network card interface), using the above method need to buy a USB switch RJ45 network card, we can go to x PO search "USB Turn RJ45" can be found, about forty or fifty yuan appearance, as shown in the following figure:
Because the Mil
What if the wireless router does not surf the Internet?
First of all, of course, plug in the power cord, next is the network cable to connect the hardware equipment. The blue RJ45 interface in the figure is a WAN (usually only 1) connected to the ADSL modem via a network cable, while the four yellow RJ45 interfaces are LAN ports (usually 2-4), which are connected to a computer or notebook via a network ca
the local area network has specified the correct IP address.
(2) Use the ping command to see if other computers can ping. If it does not work, it proves that there is a problem with the network connection, if you can ping but sometimes lose packets, it proves that network transmission is blocked, or network equipment contact is not good, need to check network equipment.
(3) When the entire network is not working, it may be a switch or hub problem, to see whether the switch or hub is functioni
choose an image port or an internal parser. But whenever possible, it is best to connect one of the hosts and parsers to the hub and hang the hub on the switch.
Why do you do that? This is because the trace remains unreliable even if the switch has sufficient capacity to cache all the data frames so that the image port or internal analyzer is unlikely to lose data. For example, in standard Ethernet, a RJ45 connector that is in a faulty port on the sw
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