The following channel-specific request can be sent over a session channel to request that the remote host perform a BREAK operation.

A port forwarding can be canceled with the following message.

When a connection comes to a locally forwarded TCP/IP port, the following packet is sent to the other side.

Environment variables may be passed to the shell/command to be started later.

This message will request that the server start the execution of the given command.

The remote command may terminate violently due to a signal.

When the command running at the other end terminates, the following message can be sent to return the exit status of the command.

When a connection comes to a port for which remote forwarding has been requested, a channel is opened to forward the port to the other side.

A pseudo-terminal can be allocated for the session by sending the following message.

A session is started by sending the following message.

This message will request that the user's default shell (typically defined in /etc/passwd in UNIX systems) be started at the other end.

A signal can be delivered to the remote process/service using the following message.

Execute a predefined subsystem.

A party need not explicitly request forwardings from its own end to the other direction.

An UnknownRequest is an unrecognized SSH request.

When the window (terminal) size changes on the client side, it MAY send a message to the other side to inform it of the new dimensions.

X11 forwarding may be requested for a session using the following message.

X11 channels are opened with a channel open request.

The message below is used by the server to inform the client when it can or cannot perform flow control (control-S/control-Q processing).