2: successful return (usual datatype attached as payload)
3: error return (payload = remoterr)
- 4..7: reserved.
+
+ 4..7: idem, with group communication (ask for forward)
+ list of receivers (and path for answer) placed before the
+ payload
msg[6..8]: message serial (for answers; omitted for one-ways)
short in binary encoding (loop every 65536)