Configure a web proxy To configure web proxy authentication on the Lifesize desktop app: Select File > Network Configuration. Choose one of the following: No Proxy to disable use of the web proxy. Manual proxy settings to enter a host, port, username and password. A Change System Proxy Settings link appears if you wish to edit Network system preferences. System proxy settings to use OS X or Windows settings for proxy configuration. If already signed in, you must sign out and sign back in for the settings to take effect.