Signaling and signaling
Signaling is a telecommunications network, between terminals and switches, and a conversation information transmitted between switches and switches. Its role is to control the connection and transfer network management information of the channel. Signaling in the telecommunications network is divided by its function, there are three categories: 1. Select signaling "Select" means the relevant functionality that completes call established. Dial-numbered digital codes and their auxiliary signals belong to such signaling. Because, in the user dial, the signaling system should select the route to complete the connection. With the emergence of various new services, not only have the signaling of the continuation of the other party, but also the signaling necessary for business processing. For example, there is a login signaling such as a zooming dial. 2. Monitor signaling so-called "monitoring" is to monitor the status of the telecommunications network and the user. In the telephone network, the monitoring signaling is information that reflects the user pick, dial, occupied, hang up, and unpacking. 3. The run signaling is a signaling that represents the switch or terminal operation and the continuous state, including dial tone, ringing tone, busy tone, etc. Signaling can be divided into two categories depending on the transmission interval: a class is a user signaling and a signaling that is transmitted between the user and the switch. For example, information reflects the state of the user's shortage, dial, and hang up, and belongs to this kind of signaling. Another class is a signaling that is transmitted between the switch and the switch. Such signaling is divided into two categories: road signaling and public channel trust. In the aspect signaling mode, the signaling and telephone communication signal use a transport channel. This is a signaling method commonly used in the previous electromechanical switch. The public channel signaling method is to separate the transfer of signaling information and the telephone circuit, and a signaling method that is transmitted through a dedicated signaling link. A signaling link can be used in many telephone circuits at the same time. In the mid-1960s, the first public channel signaling recommended by CCITT was "No. 6 Public Channel Signaling". It is designed according to the characteristics of the simulated telephone network. Although in 1972, it is still very good to adapt to the development of digital network and integrated business digital network. So, CCITT also proposed 7 for digital telecommunications network. Public channel signaling method. This signaling mode is currently being widely used. Signaling system is like a neural system in the telecommunications network. With the modernization of the telecommunications network, especially the digitalization, business integration, intelligence, and signaling system. Modern signaling systems are not only available for telephone network, data network, integrated business digital network, but also to transmit various data information between various switches and business centers, adapted to multimedia communication development.
