Rush about computer networks

Simple, you can refer to the method of Meiping's right-click cracking.

Only provide ideas::Blocked run,It's actually achieved by modifying the registry.,It's OK if you change the registry.。。 If the registry is locked, unlock it.

In the system root directory system32 talk about copying to desktop rename, say that this file is copied to the system root directory system32 to overwrite the original, log out and press the shift key indirectly, in normal cases there will be a command prompt, and then execute the command net user administrator 123

Try this method:

In the system root directory system32 talk about copying to desktop rename, say that this file is copied to the system root directory system32 to overwrite the original, log out and press the shift key indirectly, in normal cases there will be a command prompt, and then execute the command net user administrator 123

It will prompt you to change the password successfully.,Haha,Next。。。 You know what to do!!

Right-click on the taskbar > Properties > Start Menu > Customize > Advanced drop-down list, the last item is to run, and tick the small check.

77 is converted into binary to get 01001101. There is a subnet mask to get the host bit borrowed 6 bits. So the broadcast address should be 01) Now the broadcast address is all 11 from this post

11111111。The corresponding decimal system is: is the answer to this question.

1.The 4-level digital signal here should be able to achieve 2-bit Hz, and preferably 20Mbps transmission capacity.

2.Simplex: Broadcasting - information can only be transmitted from the radio station to the radio, unidirectional irreversible.

Half-duplex: walkie-talkie-information can be exchanged with each other, so it can be called duplex, because information can be obtained in both directions, but at the same time can only be transmitted by one party and received by the other party, and the transmission and reception cannot be carried out at the same time, so it is called half-duplex.

Duplex: ** - Both parties can send and receive messages at any time during communication.

3.Multiplexing technology is a technology that uses a single link to transmit multiple signals at the same time. Modern ** have more transmission capacity than the average demand of a single user, and the use of multiplexing technology can maximize the transmission capacity of the system.

4.Frequency-division multiplexing.

It refers to a multiplexing technology in which the carrier bandwidth is divided into a variety of sub-channels of different frequency bands, and each sub-channel can transmit a signal in parallel. FDM is commonly used in broadband networks where analog transmissions are made. In a communications system, the bandwidth provided by a channel is often much wider than the bandwidth required to transmit a signal.

If it is very wasteful for a channel to transmit only one signal, in order to be able to make full use of the bandwidth of the channel, the method of frequency division multiplexing can be used. In a frequency division multiplexing system, the available frequency bands of the channel are divided into several non-overlapping frequency bands, and each signal is transmitted in one of the frequency bands, so that they can be filtered out separately by a filter and then demodulated and received separately.

Time division multiplexing (TDM) is divided according to the time of transmission signal, which enables different signals to be transmitted at different times, dividing the entire transmission time into many time intervals (slot time, TS, also known as time slots), and each time slice is occupied by a signal. TDM enables a single circuit to transmit multiple signals by cross-transmitting a portion of each signal over time. At every brief moment on the circuit, only one signal exists.

Because digital signals are finite discrete values, TDM technology is widely used in digital communication systems including computer networks, while FDM is generally used for transmission in analog communication systems.

on our correspondence. Oh, I hope it helps!!

In order to ensure that the first bit of the zhen does not have a collision and reaches the destination correctly, it must be guaranteed that the possible collision signal is returned before the end of the transmission, because if the transmission is completed within 2t, the collision cannot be detected.

Under extreme conditions, the maximum distance between two transceivers (allowing 4 repeaters) in a LAN is 2500m, 5000m round-trip, and the delay characteristic of coaxial cable is 5us km, that is, in case of conflict, the end-to-end round-trip delay is 25us. However, this is the ideal delay, considering the extra delay of the repeater, in the worst case, the estimated delay is 45us, plus the enhanced conflict needs to be sent 48bit, and the receiver needs to accept the 48bit before confirming the collision, that is, in the increase, total, so usually Ethernet is taken as the length of the contention period (transmission 512bit, that is, 64 bytes of time), that is, the length of the Zhen is at least 64 bytes.

Ethernet sets the contention period at microseconds, which is a hard and fast rule.

In binary, it is expressed as, the subnet address, host address range, subnet broadcast address, subnet mask, ,, and department 1 2 3 4 5 6