> ## Documentation Index
> Fetch the complete documentation index at: https://www.cometchat.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Properties and Constraints

> Properties and Constraints for CometChat REST API.

Properties and constraints for the Calls APIs.

## Calling

| **Property**             | **Constraints**                                          |
| ------------------------ | -------------------------------------------------------- |
| Maximum users per call   | 50                                                       |
| Default video frame rate | 30 FPS                                                   |
| Video resolution         | Min 180p, max 720p (varies by layout and user bandwidth) |
| Media encryption         | SRTP                                                     |
| Audio codec              | OPUS                                                     |
| Video codec              | H.264                                                    |