VoIP technical architecture

There are some problems with the H.323 Protocol (only a limited MCU is not supported for multicast; its IP telephone network still needs to go through the Local PSTN Circuit Switching Network at the access end), and then MGCP is customized, the purpose is to break down H.323 functions into two parts: Media Gateway (MG) responsible for media processing, and the Media Gateway controller (MGC) that controls call establishment and control.

Four elements of the VOIP Architecture:

Media Gateway, media gateway controller, voice server, and signal Gateway (related control during the switching process to determine whether a call is established or not, and related value-added services, converts an SS7 signal to an IP packet ).

SIP features are almost the opposite of h323. It is a simple Session Initialization Protocol that only provides the setup and control functions of sessions or calls. Supports single-point broadcast (unicast) and multicast. That is to say, users can join an existing video meeting at any time. SIP is an application layer protocol that can be transmitted over UDP or TCP.

The VoIP gateway acts as an interface for transmitting data from a traditional PSTN network to an IP network, through which you can call a network by using a traditional phone.

The ip pbx voice switch must not only take over the positions and functions of the traditional voice switch, but also become a medium for voice and information integration.

After an IP phone converts a voice signal to an IP packet, the ip pbx determines the transmission direction of the packet through signal control. When the end of a call is a general call, ip pbx sends the IP packet to the VoIP gateway, converts the IP packet, and then returns the packet to the general tdm pstn circuit switching network.