What is a ping

What is ping? Often a netizen asked me this question, in fact, the word ping originally originated from the sonar detection system, intended to refer to the pulse signal from the sonar equipment. In the development of the Internet, the process of detecting the connectivity between two nodes in the network is very similar to the sonar detection process, so the name "ping" is used to represent the interoperability of the test two points. In the IP world there is a protocol called ICMP, namely: Internet Control Information Protocol, Ping is to follow the ICMP protocol to detect the connectivity between two points! Take the Windows system as an example, what we call the ping value is actually "time" followed by the value! This value is actually a probe message from the user host after the network to reach the destination host, and then from the destination host through the network to return to the user host this process of the total period! Now let's talk about the ping principle, the connection between ping and broadband.

To understand the ping value, now let's look at what bandwidth is! In short, bandwidth is the ability of the network to transmit data. If you make an analogy between the bandwidth and the truck, then 1M of broadband can be seen as carrying capacity of 5 tons of small trucks, 2M bandwidth is 10 tons of medium-sized trucks, and 4M bandwidth is 20 tons of large trucks.

Now there are 100 tons of goods to be transported from Shanghai to Beijing, because the distance from Shanghai to Beijing is certain (about 1200 kilometers), the speed of the truck is also certain, so in the case of no traffic jams, no matter what car can guarantee 100 kilometers per hour. Well, obviously if you use a big truck, you just have to run 5 times to complete the task, and the minivan needs to run 20 times! Regardless of whether the cart runs a round trip for 24 hours. What do you have in mind? Yes, a cart run a round-trip time, in fact, is the ping value. 100 tons of cargo is the data you want to access, the truck's capacity is your bandwidth! Obviously, in the absence of traffic jams, that is, when the network is not busy, the ping value should be stable and will not change due to bandwidth changes. The use of higher bandwidth simply increases the ability to acquire data, or simply improves the ability to access data every time.

Of course, if the line is not stable or the flow is very large, that is, traffic jams, the ping value must be big, because the ping data blocked on the road ...

Now let's take a look at how Ping works:

1, the user on the host (can be any support TCP/IP protocol device) to do ping, such as: Ping 192.168.1.1;

2, the system will send an ICMP message to the destination IP (192.168.1.1), and timing;

3. The host with the destination IP address will reply to this ICMP message after receiving the message, and the reply message is encapsulated in another ICMP packet and sent back to the host that initiated the ping operation;

4, the user host receives the destination host to reply the ICMP message, the timing and the output result.

The relationship between the ping value and the bandwidth has been explained clearly, and I believe everyone understands it.