This proxy implements a default SSH proxy based on AbstractSshProxy. A number of higher-level attributes have been defined that allow easy configuration of the various services offered by SSH (e.g.: port-forwarding, etc.). Port-forwarding, X11-forwarding, and agent-forwarding are disabled by default, the clients may open only session channels. The following client requests are accepted in the channel: window-change, pty-req, shell, exec, subsystem, signal, exit-status, exit-signal, and xon-xoff. The env request is not permitted. Only known host keys are accepted on the server side.