Nowadays, IP telephony is a well-known term. The so-called IP telephony is relative to traditional telephony. Its biggest advantage is to make full use of the existing telephone line and transmit voice over the ubiquitous Internet. This greatly reduces the cost of calls and is therefore highly appreciated and respected by users.
Before we understand IP telephony, let us first explain what IP means. IP is the abbreviation of English Internet Protocol. Its Chinese name is "Network Protocol". It is the basic protocol for data exchange between different computers on the Internet. In other words, it is the main bridge for "communication" between different computers on the Internet. Understand this point, it is not difficult to understand that IP telephony is actually the communication network to realize real-time transmission of voice information through TCP/IP protocol, to achieve the purpose of mutual communication between people.
Principle of VoIP
Usually, when we make a normal call, whether it is a local call or a long-distance call, both parties must occupy a temporary special line, and the line must not be occupied by others during the call. However, in fact, this call line can not be used 100%, and most of it is wasted.
The biggest difference between an IP phone and a regular phone is that it makes full use of the Internet. Based on the TCP/IP protocol, the voice signal of the caller is sampled and digitized by a special device or software, and compressed and packaged at the same time. The voice information is converted into small packets, which are freely searched for free space on the network, and transmit voice information to the other party. After receiving the voice packet, the other party's special equipment or software decompresses and restores the analog signal to the analog signal. phone. In this way, although it seems that the process is very troublesome, it is not necessary to establish a dedicated line during the call, but only use the network to see the stitches, which greatly saves the cost of the call, which is why the IP phone is so convenient.