For each of the proxy servers there is a an option of upstream proxy connection.
By default UserGate HTTP proxy server works on port 8080. When connecting to HTTP proxy cascade, authorization on parent HTTP-proxy is possible.
SOCKS proxy is useful for running the programs which support the Socks5 protocol, for example ICQ or mIRC. Socks proxy works on port 1080 and is disabled by default.
FTP proxy settings are almost the same as HTTP and Socks proxy settings, except for the port number.
In FTP client settings passive mode needs to be established when working through the FTP proxy server.