TeamViewer may be installed with an installation procedure, although the 'Quick Support' version will run without installation. To connect to another computer, TeamViewer has to be running on both machines. To install TeamViewer, administrator access is required, but once installed it can be run by any user. When TeamViewer is started on a computer, it generates a partner ID and password (user-defined passwords are also supported). To establish a connection between a local client and a remote client, TeamViewer generated ID and password of either client are required. The local client requires the remote client's ID and password to gain control over the remote client, whereas the remote client requires the local client's ID and password to gain control over the local client.

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TeamViewer uses RSA private/public key exchange (2048-bit) and AES (256-bit) session encryption.

In the default configuration, TeamViewer uses one of the servers of TeamViewer.com to start the connection and the routing of traffic between the local client and the remote host machine. The software then determines how to establish a connection. In 70% of the cases after the handshake, a direct connection via UDP or TCP is established; the other connections are routed through TeamViewer GmbH's router network (via TCP or HTTP-tunneling).