Knowledge about network bandwidth management

In general, to manage network bandwidth, first you need to know what network bandwidth and a 10 M bandwidth actually mean?

In fact, 10 m of network bandwidth does not mean that the traffic per second is 10 m. The 10 m here is actually a "bit" concept, which is different from what we usually call the 10 m file size, if your ADSL bandwidth is 1 Mbps, theoretically, the download speed is up to 128 KB per second. That is to say, it takes at least 8 seconds to download a 1 Mbps file.

In normal network applications, evaluating the bandwidth usage of a link is usually expressed by the link bandwidth utilization. For network devices, the link bandwidth utilization of each port varies according to the working status of the port. In the full-duplex status, there are two different indicators: inbound and outbound, that is, the efficiency of sending or receiving data per second on this port. Therefore, when calculating the bandwidth utilization of a link, the bandwidth usage may exceed 100%, which means the full duplex operation of the link is ignored.

Generally, we are selecting network devices. The faster the speed, the better. We can't see the hundreds of megabytes, Gbit/s, or even Mbit/s network. We can't wait for 10 Mbit/s to reach the desktop. In fact, this is an extreme mistake, the management of network traffic involves many areas. Sometimes the bandwidth of network equipment is enough, but your server cannot keep up, and the operating system speed cannot keep up. In fact, for the desktop, a hundred megabytes is enough.

Network latency and network jitter are also common indicators in network bandwidth management. This is not much to mention. However, we often ignore a key indicator, which is the bandwidth utilization of the backboard,

It may not be very professional, but it is very important. If the bandwidth of the backboard is not enough, the port speed is fast and useless. In most cases, Port Data exchange must be performed through the backboard (actually equivalent to the bus, therefore, we also need to consider this issue when selecting network devices. It is especially important for core switches in the network.

Therefore, in the network design process, we must consider the problem comprehensively. Instead of blindly pursuing a high bandwidth speed, we sometimes get the opposite effect.

 

The next article will talk about how to measure these indicators