3.7.4 Higher-Layer Triggered Events

When a create tunnel is requested by the higher layer, it can also issue a Cancel Tunnel Creation request before the tunnel is created. Once the tunnel is created, the higher layer can also issue a Close Tunnel request, which initiates the Connection Close phase (section 3.3.5.5).

The higher layer initiates the channel creation once the tunnel has been authorized. After issuing a Channel Creation request, it can issue a Cancel Channel Creation request before the channel is created. After the channel is created, the higher layer can issue a Close Channel request.