About Matrix Matrix is an open protocol for decentralised, secure communications.
Matrix Manifesto We believe:
People should have full control over their own communication. People should not be locked into centralised communication silos, but instead be free to pick who they choose to host their communication without limiting who they can reach. The ability to converse securely and privately is a basic human right. Communication should be available to everyone as a free and open, unencumbered, standard and global network.
This is also dependent on who is running the server and how it’s set up. If it’s the matrix.org you’re using, I couldn’t tell you. If it’s someone hosting/you’re self-hosting, you need a STUN server for traversing NAT. It’s not part of the default Synapse docker install and I’m not sure about non-docker installs.