View the application of soft exchange devices in multimedia services

Softswitch devices are widely used in many businesses, and their functions also support these businesses to meet more user needs. To support video and multimedia services, softswitch devices should have multi-point control functions to support the following functions:

(1) Support for call processing: Allows terminals to join and exit multimedia meetings, including Ad hoc and Non-Ad hoc meetings, and provides the ability to dynamically modify calls and connections; you can add or delete communication participants at any time during the communication process without interrupting other call connections. You should be able to negotiate voice/Video Coding/Decoding with video and multimedia terminals.

(2) Meeting control function: it can control MP and video multimedia terminals, establish/disable logical channels for voice, video, and data, and support the Chairman's meeting control mode, including viewing the venue, automatic browsing, applying for/releasing the Chairman, disconnecting/adding the venue, muting/canceling the venue, closing/canceling the venue, and broadcasting the venue; the chairman can assign a "token" to the terminal requesting to speak during control and control the MP switching video signal according to the instructions of the "token" owner; able to control MP switching between the chairman's control mode and the voice control mode.

(3) resource control function: Various media conference resources on MP should be requested for video multimedia terminals, including speech codec resources, multi-channel speech mixing resources, video codec resources, and centralized data processing resources; control information on resource usage reported by MP, changes in the status of physical entities that receive MP reports due to failures, recovery, or management. These physical entities can include carrier endpoints and media resources, and can instruct MP to indicate resources or resource sets dedicated to a meeting.

(4) QoS management function: it should be able to control the MP in the jurisdiction and report its status information, such as system resource usage, status information, disconnections, codec type, bandwidth, etc. It can control the processing of voice and video by MP, such as the cache size, audio/video codec type, Echo offset, mute compression, comfortable noise, and speed.

(5) authentication and authorization: It is necessary to authenticate and authorize the MP in its jurisdiction to prevent access to illegal devices. It can work with the authentication system to complete conference authentication for multimedia users. User Authentication includes the user ID, account password, user type, meeting ID, meeting password, and business type.

(6) protocol functions: supports communication between H.323, SIP, H.248, MGCP, and multimedia terminals; supports H.248 protocol control of MP and media servers; supports SCTP traffic control transmission protocol, the H.248 protocol data can be transmitted using SCTP protocol. The H.248 protocol control adapter gateway can be used to access H.320 and H.324 terminals.

In addition to the above multi-point control function, the softswitch device should also have the traffic detection function. In terms of management, Softswitch equipment should be able to configure, detect and control the traffic of various Smart terminal devices, so as to avoid the unlimited use of Bandwidth Resources of bearer networks by various Smart terminal devices, you can also perform traffic statistics on devices in a specified group, configure the available bandwidth limit for various Smart terminal devices, and restrict the services of devices that have exceeded the bandwidth limit. For point-to-point video multimedia services, Softswitch devices can be billed Based on the session duration. They can be billed separately for the session duration of each media type in the call, or by traffic, billing is based on the traffic of each media type in the session. You can also make a combination of billing, that is, the conversation sound is billed on time and long, and the video or data is charged by traffic. For point-to-point and Multi-Point Video Media Services, Softswitch can be billed Based on the session duration. You can also separately charge for the call duration of each media type in the call. At the same time, you can also pay by traffic, you can separately charge for multiple sections, you can also pay by the total traffic of the media in the call.

Implementation of multimedia video services in softswitch Devices

1. Implementation of point-to-point video and multimedia services

The point-to-point video multimedia service is the same as a common call. It is still a caller and a called user involved in the call process, but its media stream contains both voice and video. Therefore, the control process of a Softswitch device is basically the same as that of a common call. There are only two differences: first, the control process for the gateway/terminal is slightly different, and the point-to-point video multimedia service adds control over the video stream. Second, the protocols used in this control process may be different. Point-to-point video multimedia services involve H.323, SIP, or H.248. From a practical perspective, point-to-point video multimedia services should be able to call each other with ordinary telephone terminals. Because ordinary telephone terminals do not provide video functions, the call between the two must shield the video capabilities of video multimedia terminals and only adopt the pure voice mode. This requires the softswitch device to determine the type of a specific call based on the active and called users, especially the terminal capabilities of the called users.

2. Implementation of point-to-point multi-point video multimedia services

Point-to-point multi-point video multimedia services can be established in Ad hoc and Non-Ad hoc modes. The Non-Ad hoc Mode means that the softswitch device Reserves Resources for the meeting in advance. When the meeting time is reached, all participants can call a special meeting number to join the meeting or call the softswitch device to join the meeting. Ad hoc means that the Conference initiator invites terminals that need to attend the meeting to join the meeting. The meeting resources are temporarily allocated as needed. Since the Non-Ad hoc mode reserves meeting Resources in advance, it can ensure the successful establishment of the meeting. However, due to the fact that the attributes of the meeting have been agreed in advance and cannot be changed, the meeting is not flexible enough and complicated. In Ad hoc mode, meeting resources are not reserved in advance, but are allocated dynamically on a temporary basis as needed.