minor spelling fixes, and explain the command protocol..

PROTOCOL.md

@@ -1,7 +1,7 @@
 Protocol
 ========
 
-The responder will be the node under control (irrigation controler), and
+The responder will be the node under control (irrigation controller), and
 the initiator will be the server.
 
 The responder will always respond with one and only one packet.  That
@@ -25,7 +25,7 @@ initiator:
 send_enc(<16 bytes random data> + 'reqreset')	# nonce injection
 send_mac(8)
 
-respondant:
+respondent:
 send_enc(<16 bytes random data>)	# nonce injection
 send_mac(8)
 
@@ -33,7 +33,7 @@ initiator:
 send_enc('confirm')
 send_mac(8)
 
-respondant:
+respondent:
 send_enc('confirmed')
 send_mac(8)
 
@@ -45,7 +45,7 @@ The new key/session does not become active till this point.
 
 In order to handle a reset and prevent a replay attack, the existing
 session, if any is maintained till the completion of a reset request.
-Only after that, does the old conenction key get removed.  This does
+Only after that, does the old connection key get removed.  This does
 mean that after a reset request, it is required that both sides attempt
 to decode each packet w/ both keys.
 
@@ -54,4 +54,19 @@ Where type is to be:
 	ecdh - Results of an ECDH exchange, key = K || K_A || K_B
 	ecdhe - Results of an ECDHE exchange, key = TBD
 
+Once the session has been established, the initiator will send commands of the
+following format:
+	<cmd byte> <args>
+
+Currently the only defined type for args, is a 4 byte integer in little endian
+format.  Additional types may be added later.
+
+The following commands are defined:
+TERMINATE: 1 -- no args: terminate the session, reply confirms
+WAITFOR: 2 -- args: (length): waits for length seconds
+RUNFOR: 3 -- args: (chan, length): turns on chan for length seconds
+
+When the responder receives a command, it will process it, and send back
+a response w/ the same command byte as an acknowledgment.
+
 Note: look at: https://monocypher.org/manual/advanced/elligator when doing ECDHE