This document explains some of the basic concepts you may encounter while using TRTC services.
In TRTC, business and projects are managed with applications. You can create different applications for your projects in the TRTC console to separate their data. Each Tencent Cloud account can create up to 100 TRTC applications.
Tencent Cloud uses
SDKAppID (application ID) to uniquely identify TRTC applications. It is generated automatically when you create an application in the TRTC console. Applications that do not have the same
SDKAppID cannot communicate data with each other.
UserID (user ID) uniquely identifies a user in a TRTC application.
UserID is a mapping of the user accounts of your project in Tencent Cloud. Normally, you can use a username as
UserID should preferably be 32 bytes or shorter. It can contain digits, underscores, and letters (case sensitive).
A room is a space where users can receive each other’s audio and video data in real time.
Rooms are virtual spaces TRTC uses to separate one user group from another.
Only users in the same room can receive each other’s audio and video.
A user can be in only one room at a time. A user who is already in a room must exit the room before they can enter another.
The first user who enters a room is the owner of the room. Room owners cannot close rooms manually.
In call modes, TRTC closes a room when all users leave the room.
In live streaming modes, if the last user who exits a room is an anchor, TRTC will close the room immediately; if the user is an audience member, TRTC will close the room after 10 minutes.
A user is removed from a room 90 seconds after an unexpected disconnection occurs. If all users are disconnected, the room is closed after 90 seconds. The waiting time after a disconnection occurs is also billed.
If a user attempts to enter a room that does not exist, TRTC creates a room automatically.
RoomID (room number/ID) uniquely identifies a room in a TRTC application. It is a UInt32 number that you assign to a room and maintain. Its value range is 1-4294967295.
UserSig (user signature) is a security signature designed by Tencent Cloud to authenticate user logins and verify that a user is real. It helps prevent attackers from accessing your Tencent Cloud account. For more information, see FAQs > UserSig.
Push is the operation in which a user uploads local audio/video data to the TRTC server.
Subscription is the operation in which a user sends a request to the TRTC server to pull the audio/video data of a specified user.
In TRTC, users can have either of two roles: anchor (
TRTCRoleAnchor) and audience (
An anchor can push local audio/video data to the server. They can also subscribe to and play back the audio/video data of other anchors.
Audience members can only subscribe to and play back the audio/video data of anchors.
In call modes, all users in a room have the anchor role. In live streaming modes, users in a room can be either anchors or audience memebers. A user can switch roles as needed.
CDN Live Watching
CDN live watching is also known as CDN relayed live streaming. TRTC uses relayed transcoding clusters to convert its UDP audio/video streams into RTMP streams in the cloud. The streams are then pushed to a standard live streaming system and distributed through CDNs to the audience. For details, see CDN Relayed Live Streaming.
TRTC leverages the capabilities of CSS to record entire audio/video calls in the cloud. Recording files are securely saved in real time to VOD. For details, see On-Cloud Recording and Playback.
In scenarios such as CDN live watching and on-cloud recording, you may need to mix multiple audio/video streams in a TRTC room into one stream. This can be achieved using TRTC’s stream mixing and transcoding MCU cluster. The MCU cluster can mix multiple audio/video streams as needed and distribute the mixed stream to live streaming CDNs and the on-cloud recording system. For more information, see On-Cloud MixTranscoding.
A user entering a room on a dumb terminal will not be detected by the SDK, and remote users will not receive notifications when the user enters or exits the room.