[FreeNX-kNX] Unexpected timeout connecting

[Geoff Hoff]

> Is there anywhere a description of how [Free]Nx works? I've only been able to
> find the docs on the nomachine site which don't go into a lot of detail (and
> reading the source just gives too much for me to cope with!). I'm trying to
> get a 2nd installation going and I've got key files all over the place.

This is how it works as I understand it based on reading the scripts,
the log files, and some tcpdump output.

First the client connects to remote server via ssh and logs in as nx
using ssh keys.  The client then sends username and password to
nxserver script which is running as nx.  Then there is a second ssh
connection from the server running as nx to the server and logs in
using your id and runs the nxnode command.  The nxnode command starts
the requested service.  Probably most often it starts nxagent (which
is the virtual X server) and also starts your desktop which displays
to nxagent.  Nxnode then reports the port on which nxagent is running.
 At this point back on the client end nxproxy is started and connects
to the nxagent session on the remote server and displays your remote
session.  So I'll draw a couple of ascii pictures

user at client ssh -> nx at remote runs nxserver then ssh -> user at remote
runs nxnode which starts nxagent - reports back nxagent port

client nxproxy -> remote nxagent

The nx at remote -> user at remote ssh is transparent to the process and may
not be used in the commercial version.  I don't know  The nxproxy <->
nxagent session use cookies so that no one can hijack the connection. 
This is where the encrypt all data option is used.  The nxproxy <->
nxagent connection does not have to be encrypted, but can optionally
use ssl.

Also if using vnc or rdp instead of your X desktop replace nxproxy
with nxviewer or nxdesktop respectively.

Hopefully this makes since to someone.