Web VNC Client Requirements?

[L.M.]

Hello, thank you for answering so quickly.

Ok... I understand what you are suggesting... the problem could be related
to the fact that machine B filters outgoing connections...

Ok, I am trying to test that on my machine... but I am not sure I can filter
outgoing connections...! I which I could check that myself...

Anyway, I am going to go on searching
and yes your answer helps a lot!

Thank you very very much, regards,

--
Leon
================================================================


----- Original Message -----
From: "THEIS Jean-Marie 139708" <Jean-Marie.THEIS "at" cea.fr>
To: "L.M." <lmbox "at" wanadoo.fr>
Cc: <vnc-list "at" realvnc.com>
Sent: Monday, June 04, 2007 1:37 PM
Subject: RE: Web VNC Client Requirements?


Hello

There are two cases ( assuming that you uses VNC between two windows
stations without having changed port option in the connection menu on VNC
server side )
* First case using VNC Viewer as client on machine B :
  Vnc viewer on machine B uses an outgoing connection to the incoming ( and
listening ) port 5900 of the VNC server running on machine A .
  This means that the firewall protecting machine A must allow incoming
connections to port 5900 of machine A.
This means also that if the firewall protecting machine B filters outgoing
connections, it must allow outgoing connections to port 5900 of machine A.
All the remaining protocol then happens between B port X and A port 5900.

 * Second case using a Java client on host B ( which then connects to
http://HostA:5800 ):
Http browser of machine B uses an outgoing connection to connects to
incoming port 5800 of the VNC server running machine A .
This port 5800 is used to download the java applet vncviewer.
Once downloaded, the the java Vnc viewer on machine B uses an outgoing
connection to the incoming ( and listening ) port 5900 of the VNC server
running on machine A .
All the remaining protocol then happens between B port X and A port 5900.
This means that the firewall protecting machine A must allow incoming
connections to port 5900 AND 5800 of machine A.
This means also that if the firewall protecting machine B filters outgoing
connections , it must allow outgoing connections to port 5900 AND 5800 of
machine A.

***

In both cases port 80 is NOT used at all !!!

Best regards

Hope to help

Jean-Marie Theis
================================================================
-----Message d'origine-----
De : vnc-list-admin "at" realvnc.com [mailto:vnc-list-admin "at" realvnc.com] De la
part de L.M.
Envoyi : lundi 4 juin 2007 11:27
@ : vnc-list "at" realvnc.com
Objet : Web VNC Client Requirements?

Hello,

Suppose the situation is the following:
----------------------------------------------
- running VNC server on host A (network A),
- running VNC client using an "Internet browser"
  and the "Java Runtime Environment" on host B
  (network B).


Problem:
-----------
HOW and WHY host B or its network (network B)
could prevent host B from connecting to the VNC server on host A?
Which could be the reasons?

  - Could the "Java Runtime Environment" be responsible for that?
  - Could it be because the VNC client on host B uses ports other
    than port 80 to communicate with the VNC server on host A?
    (Does the client also uses ports 5800 and 5900?)
  - In other words, are there any requirements on the client other
    than having an "Internet browser" and a "Java Runtime Environment"
    available?

I am only interested on the client side of the communication
(suppose everything is OK on the server side: no firewall, etc.).

Please help!

Thanks in advance,

--
Leon