Repeater: Multiple Viewers, Single ID and Server

[stever]

We'd like to request that the Repeater be modified to allow multiple viewers to connect with a common ID to view a single server.

In a distance learning environment, it would be very desirable to allow the repeater to have multiple viewers connect to one server so different people at different computers can see what's going on the server at the same time.

This can be done today by giving each viewer a unique ID and starting an additional server process for each viewer with matching IDs. However, this means there is a connection from the server to the Repeater for each participant and it begins to eat bandwidth and CPU cycles very fast.

It would be far more efficient (and practical) to have only one connection from the server to the Repeater and for the Repeater to distribute to all viewers with a common ID. The repeater could be placed on a system that has sufficient bandwidth and computing power so no matter where the server was it wouldn't be bogged down.

We're a small software house so we'd also entertain the idea of providing coding resources if that would be of interest.

Thank you for your consideration,

Steve

[Rudi De Vos]

A repeater is not suitable for it.

serverA(encrypt)->data->repeater->data->viewerA(decrypt)
serverB(encrypt)->data->repeater->data->viewerB(decrypt)

The repeater can not read the actual data, he just pass it from A to B.

To make it happen
-The repeater need to be a trusted part. He need to decrypt the server data. And he need to encrypt it again for each viewer. (CPU intensive)
-Repeater need to cache the init packages to be able to initiate a new viewer.
-VNC use streaming encoder, zlib package2 depend on package1. This encoder will not work. Encode need to be modified to make packages independed.
A lot of work...

You better use some webserver. VNC Server update web and each viewer connect via a browser to the webpages ( Same method as used for webcams)

[stever]

Well, that's what I get for not knowing how the Repeater really works!

To my simple way of thinking, it doesn't seem like the Repeater should have to know anything about the data. Like you said, "The repeater can not read the actual data, he just pass it from A to B." If it accepts a packet from ServerA and just passes it to ViewerA (not knowing what it's passing) then why not just pass the same packets to ViewerB and ViewerC the same way?

Oh well... you're the expert so I guess there's not much else to do. Thanks for your reply and if there is anything else you can think of, just shout!

Regards,

Steve

[Rudi De Vos]

What you need is
http://sourceforge.net/projects/vnc-reflector/

[stever]

Thanks, that sounds exactly like what I'm looking for.

I'll set the VNC-Reflector up, point my UltraVNC Viewers and Server at it and see what happens!

Thanks again for all your help!

Steve

[stever]

Wow, very good information here. Just wanted to give you, or anyone interested in, the results.

Documentation is a bit cryptic, and making the host files and password files a little odd, but the thing works great. In fact, I connected a RealVNC server with both UltraVNC and RealVNC viewers... that worked. Then I connected a UltraVNC server with a mix of RealVNC and UltraVNC viewers and that worked too... Performance isn't too bad either. How cool is that??

Here's what I used to make it work.

Command line parameter:
vreflect.exe -p PASSWD_FILE.txt -l 6281 -t HOST_INFO_FILE.txt

HOST_INFO_FILE.txt
*:6282 <PASSWORD>

PASSWD_FILE.txt
<PASSWORD>

To connect a UltraVNC viewer:
vncviewer /shared /password <PASSWORD> myServer.IP:6281

To connect an UltraVNC server:
winvnc -connect myServer.IP:6282

So, you'd think I'd be content wouldn't you?? Well, I'm that kind of guy. The only downside to the VNC-Reflector vs. UltraVNC Reflector is the missing ID. It would appear that there is no concept of the ID in the VNC-Reflector so you couldn't have concurrent sessions with different servers.

I know, I know... never satisfied. But I think I'm going to call it a win anyway and just make sure no two training sessions (that use sharing) are running at the same time.

Thanks one more time for pointing me in the right direction. Very much appreciated!!

Steve

[Emdy]

stever, ur suggestion helped me a lot, thanks.
just want to add, u can use concurrent sessions with different servers.
./vreflect.exe -p PASSWD_FILE2.txt -l 6281 -t HOST_INFO_FILE2.txt
./vreflect.exe -p PASSWD_FILE1.txt -l 6181 -t HOST_INFO_FILE1.txt
./vreflect.exe -p PASSWD_FILE3.txt -l 6381 -t HOST_INFO_FILE3.txt
multiple instance of vnc reflector.
i've specified separate log file and pid file name also in the CLI.
i've simply copy-pasted same file 3 times and renamed to have same passwords. Only port, log, pid were different. also used separate start & stop script for each instance.
See [topic=13697]here[/topic], this topic thread is for discussing vnc reflector.
i'm wondering how come there is no good working guide yet for this vnc-rfl, and it was released before 2003 !
~ Emdy . Sep23,2008,tue,1:51P,Gmt-08:00.