Ragel for network protocols?

[Stéphane Bortzmeyer]

I'm trying to experiment with Ragel for specifying network protocols,
which are often described as state machines.

All the Ragel examples I can find are for parsers, not for protocol
state machines. Reading the documentation, I still cannot write a
state machine for a protocol as simple as:

                        Open
                       /        \
                       /          \
 +--------------+            \  +-------------+
 |                     |            > |                   |
 | Door-closed  |              |  Door-open |
 +--------------+               +-------------+
                       ^            /
                         \          /
                          \        /
                         Close

Any sample code somewhere?