Network card speed is no longer frequency change LAN transmission speed upgrade graphics and text Tutorials _ Networking Tutorials

Now many units have been built intranet, the general enterprise network is mostly using twisted-pair to connect the network card mode to communicate. The twisted-pair wires are usually 5 lines, and the transmission rate is 100MB. and the network card is a certain difference, many network cards are taken 10mbps/100mbmps Adaptive network card, that is, the transmission rate between 10MB and 100MB automatically match. For this network card, in the transmission file, theoretically, more than 10 MB of a file, should be able to transmit over a few seconds, but in fact the transmission is relatively slow, especially in the transfer of small files, its relatively time significantly longer. What is the cause of this phenomenon? In fact, is the network card adaptive in the mischief.

First, the cause of the error analysis

Using 10MB/100MB Adaptive network card, when issuing a request for transferring files, the system will automatically communicate with the other's network card to match the appropriate transmission rate.

If the other side of the network card to take the 100MB standard speed, then the Adaptive network card is matched to choose the same speed for transmission, the same if the other side to take 10MB, Adaptive network card will choose 10MB. This kind of matching communication often needs to be repeated repeatedly to ensure the stability of signal transmission.

Because of a lot of negotiation, this will occupy a certain amount of time, in the transfer of small volume of files, it occupies a relatively long time, the speed of the transmission is relatively slow, and the larger the volume of the transfer of files, the smaller the relative time they occupy. Therefore, we can see that the Adaptive Network card has a major impact on the transmission of the small amount of information. And on the network, the most of the packets are within 1MB, so the impact on the overall network performance is still relatively large.

Two, let the speed fixed down

As can be seen from the above introduction, the reason for the slow speed is the need to match the rate of transfer selection before transmission. If we fix the speed of the NIC, we can skip this step and send it directly.

The way in which the transmission takes place is determined by the structure of the network. Generally there are two modes, if the computer in the network generally using 10m/100m adaptive or most of the 100M network card, then we recommend that directly enforce the 100MB full duplex speed transmission; If there are some nodes in the network that take 10M network cards (which is now rare), or the network transmission rate is not stable, it can also be reduced to 10MB to ensure the stability of network transmission.

In the system, the rate of setting 10m/100m Adaptive network card is very simple. Just right click on the Network Neighborhood icon on the desktop, open its Properties window, where you can view the local connection icon, open the Properties window of the local area connection again, and you can see the network card brand and model of "use when connected" above the General tab, click the Configure button (Figure 1) to open the Hardware Properties window for the network adapter. , switch to the Advanced tab, select the "Connection Type" item in the property list, and the default value is "Auto-negotiation", that is, automatically adjust at 10m/100m two rates. And we should choose "100BaseTx full Duplex", that is, 100mbps/Full-duplex (Figure 2).

Figure 1



Figure 2

Tips: Depending on the network card, the hint may be slightly different, such as using the Intel (R) pro/100 ve Network, then its properties are displayed in Chinese "link speed and Duplex", you can set up according to the network card to find their own.

Such a simple setting of the NIC can change the network transmission file waiting time is too long, transmission rate instability and so on, to restore the smooth network. If you are troubled by such a problem, do not try to follow the method introduced by the author.