A voice trunk gateway is a network device that is mainly used to connect a public switched telephone network (PSTN) to a next-generation network (NGN) or a softswitch network to realize the function of IP packet to TDM (time division multiplexing). The following is a detailed explanation of Voice Trunking Gateway:

  Definition and Function:

  A voice trunk gateway is an important part of the NGN solution and is located at the edge access layer of the NGN network.

  It connects the PSTN and NGN networks, converges voice from the IP domain to the circuit domain, and has functions such as voice processing, call processing and control, maintenance, and management.

  Main features:

  Voice processing function: it has the function of coding and decoding voice signals, and supports various algorithms, such as G.711, G.729, G.723 and so on.

  Echo control mechanism: supports echo cancellation G.168, capable of eliminating echoes within 64ms.

  Call processing and control: able to control the call according to the commands of softswitch, such as pickup, interruption, etc., and able to detect the off-hook and on-hook signals of the user's phone.

  Maintenance and management: It can establish and maintain associations with the softswitch, and report configuration status and abnormal faults of the underlying connections.

  Interfaces and Protocols:

  Interface description: Digital trunk interface is used on the voice network side, while 10/100M LAN interface, Gigabit Ethernet interface, etc. are used on the IP network side.

  Signaling and Protocol Support: Supports signaling such as No.7, NO.1, Q.931, Q.sig, etc., as well as protocols such as MGCP, H.323 and SIP.

  Application Scenario:

  Voice Trunking Gateway enables PSTN network and IP network to realize perfect integration and complete the conversion of SIP/H.323 protocol and NO.7/Pri signaling.

  It is widely used in scenarios such as enterprises, carriers and service providers that need to connect traditional telephony networks and IP networks.

  Summary:

  Voice Trunking Gateway is a key device for connecting PSTN and NGN/Softswitch networks. It realizes IP packet to TDM conversion and carries the task of voice convergence between IP and circuit domains through its powerful voice processing, call processing and control, maintenance and management functions.

  It ensures seamless connection and communication with different networks and devices by supporting multiple interfaces and protocols.