Telephone

Since its founding, the telephone has become one of the most important inventions ever. Though some people are skeptical about telegraphic replacement, the emergence of such sophisticated communication equipment has won the hearts of many people. In fact, the phone system has received multiple resale, which was linked to the world before the birth of the Internet. Because of its importance, families and businesses can not do without it. In the United States alone, most, if not all, have indoor phones.

The telephone network was an intelligent network that previously supported dumb devices (phones). All information in the telephone network and all services are included in the exchange of the telephone company. The phone on the table in the consumer's kitchen is just a speaker and a microphone. State-of-the-art TouchPhone is a very simple device, completely dependent on network services, but it can "request" by issuing the correct sound. In such an intelligent network, there is no room for innovation at the end. Of course, you can make the phone look like a cheeseburger or banana, but you can not change the service you offer. These services are completely dependent on the central exchange owned by the telephone company. Centralized innovation means slow innovation. It also means innovation led by the goal of a single company. Therefore, any content that seems not to satisfy the vision of a company with a network is denied or even actively opposed.

Mobile phones are one of the most important and commonly used tools in business. Many companies, companies, and divisions use their mobile phones every day at work, but most of us do not believe that mobile phones are tools, so we mistakenly mistakenly made a cell phone I used it. The phone is a link between us and the business and the outside world of the department. Unfortunately, you may not notice messages sent to callers or the outside world, or you may not consciously monitor them.

Using analogy: The network outlet is like a wall phone jack; it connects your phone to the outside world. "Binding" a network socket to an address (host and port) behaves just like a telephone company assigns a phone number to your home. Telephone socket in the house. ^ "SOCK_DGRAM" tells the kernel that you want UDP. When interacting with a socket in C, calling the socket () function will return a "file descriptor". Unix-like systems are known to handle many different things (including sockets) as if they were just files.