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File Transfer problem with W2K8 R2 and v1.2.1.2 64 bit

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RonnieM
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File Transfer problem with W2K8 R2 and v1.2.1.2 64 bit

Post by RonnieM »

Hi

We have three recently built Windows 2008 R2 servers in different locations, with uVNC v1.2.1.2 64 bit server installed as a service.

Everything seems to work well with the exception of transferring a file from a client to these servers, although ironically file transfer from the server to the client works perfectly well.

What happens is :
Source and destination directories selected.
File to "Send" selected.
Click on the "Send" button
Progress bar appears.
File Transfer Window disappears.
Main uVNC window unresponsive, but stays on screen.

Main uVNC window closed by user.
New uVNC session initiated.
A zero byte "!UCNPFT-" file is present in the destination directory.


This is making it impossible to transfer files to these servers, and is a major problem.

Can anyone suggest what the source of this problem might be, and any solution ?

Thanks,

Ronnie
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Rudi De Vos
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Re: File Transfer problem with W2K8 R2 and v1.2.1.2 64 bit

Post by Rudi De Vos »

Perhaps some fast check, you never know.
Check if destination folder is writable for the current desktop user.
RonnieM
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Re: File Transfer problem with W2K8 R2 and v1.2.1.2 64 bit

Post by RonnieM »

Rudi De Vos wrote:Perhaps some fast check, you never know.
Check if destination folder is writable for the current desktop user.
The servers are logged on to as Administrator in all cases, so this is not the problem.

In any event if it was a rights issue, the creation of a zero byte file in the destination directory, as reported, would not occur.

Are we any further forward in identifying or fixing this issue, which is plaguing us on these file servers, to the point that we are considering going back to an earlier version.
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Rudi De Vos
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Re: File Transfer problem with W2K8 R2 and v1.2.1.2 64 bit

Post by Rudi De Vos »

Pehaps related to this issue
https://forum.ultravnc.net/viewtopic.php?f=71&t=32713

If possible try to test the latest 1215 winvnc.exe.
ddbivens
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Re: File Transfer problem with W2K8 R2 and v1.2.1.2 64 bit

Post by ddbivens »

Testing with 1.2.1.5 on both ends...
I can't be for certain but I think File Transfer may be broken. For two days, 2-3 time disconnecting and reconnecting each day, I have tried to transfer three files to my work PC, that have failed. The failure has been in one of two ways. One way is when the File Transfer window just closes. The VNCViewer window will not respond in any way. Most of the time I can't get it to minimize or close. If it minimized, it immediately reports "VNCViewer is not responding". I usually get this message twice. If I can't get it to minimize, I use my Show Desktop button. Usually I can't get VNCViewer to do anything when I click on the icon minimized on the taskbar. Usually in a few seconds, I get the VNCViewer is not responding message. I have not been able to get a successful file transfer. The other way is for the File Transfer window to freeze. I only noticed a couple of times, but the byte count was about 22240, and for a retry after reconnecting the count was 44440. I don't know if that is significant or not.
For some reason, when I reboot a remote PC using the Windows Update "Reboot (or Restart) Now" button, it seems to cause the viewer to lock up with "Not Responding" most every time. Even after the PC has completed rebooted (I connect with another Viewer session), the one reporting "Not Responding" never comes back. I use the "X" and Close button to close that viewer. On the rarest of occasions, I have had to taskkill (via a batch file) to close the VNCViewer.exe program.
On a positive note, I have got great connections at home to a home PC, at home to my work PCs and at work to work PCs. For the the initial screen, which normally does not draw on initial connection, I usually wait 1-3 seconds after the connection, then I click the screen refresh button, which usually does well redrawing the initial connection screen, and redrawing throughout a connection usually works well. I have been able to leave connections open for very long periods and I have had very few unexpected disconnects / reconnects. The connectivity and screen refresh (not counting the first screen) and general responsiveness has been the best it has been since about version 1.1.9.3.
Thanks for listening.
sfhub
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Re: File Transfer problem with W2K8 R2 and v1.2.1.2 64 bit

Post by sfhub »

ddbivens wrote:The failure has been in one of two ways. One way is when the File Transfer window just closes. The VNCViewer window will not respond in any way. Most of the time I can't get it to minimize or close. If it minimized, it immediately reports "VNCViewer is not responding". I usually get this message twice. If I can't get it to minimize, I use my Show Desktop button. Usually I can't get VNCViewer to do anything when I click on the icon minimized on the taskbar. Usually in a few seconds, I get the VNCViewer is not responding message. I have not been able to get a successful file transfer. The other way is for the File Transfer window to freeze. I only noticed a couple of times, but the byte count was about 22240, and for a retry after reconnecting the count was 44440. I don't know if that is significant or not.
I can concur on transfer problems on slower VPN connections. On fast LAN the transfers work ok.

What I am currently doing is using the 1.2.1.2 vncviewer.exe with the server running 1.2.1.5 winvnc.exe. This combination works pretty well. I need the 1.2.1.5 server because it fixes the stuck/freeze/slow transfer problem when winvnc is running as a service.
ddbivens
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Re: File Transfer problem with W2K8 R2 and v1.2.1.2 64 bit

Post by ddbivens »

I tried that combination and it works for me also. When I need to do file transfers, I launch the 1.2.1.2 viewer. When I just want to remote control, I launch the 1.2.1.5 viewer, where I seem to get a little better response and screen refresh. Thank you for the info.
Chris
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Re: File Transfer problem with W2K8 R2 and v1.2.1.2 64 bit

Post by Chris »

We have file transfer Issues too in V1.2.1.5, only on slow (Wan) connections.
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Rudi De Vos
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Re: File Transfer problem with W2K8 R2 and v1.2.1.2 64 bit

Post by Rudi De Vos »

I will take a look again.
Slow network and FT
RonnieM
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Re: File Transfer problem with W2K8 R2 and v1.2.1.2 64 bit

Post by RonnieM »

Rudi De Vos wrote:I will take a look again.
Slow network and FT
It might help to know that we are doing this over a Satellite broadband service.

Speed down to client (viewer) is 20Mbps
Speed up to server is 6Mbps
Latency on every request circa 800ms


Just to re-iterate . . . . .

File transfer from the server to the local client (viewer) works fine.

File transfer from the local client viewer to the server often fails with a zero byte file created in the destination directory.

Bizarrely, our work around is to remote control the remote server from a local machine, and then initiate a connection back out to another local machine, and that way we can pull in the file rather than "pushing it" !!

So it really is only one direction that is the problem for us.

. . . . . . And we have been doing this for many years quite happily with older versions of uVNC (eg. v1.0.1) on much slower satellite connections than we now have !!!

Any help on this would be much appreciated.

Thanks,

Ronnie
RonnieM
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Re: File Transfer problem with W2K8 R2 and v1.2.1.2 64 bit

Post by RonnieM »

A quick update . . . .

We have just put new Win7 x64 machines into three locations where we have this problem (See thread title).

These machines have UltraVNC 1.2.0.3 64 bit installed, and file transfer is fine in both directions.

So we can confirm that the file transfer problem from local client to remote server has surfaced after version 1.2.0.3 64 bit

Hope this helps track down the problem.

We plan to change the troubled file servers to this older version in order to resolve the immediate problem, but this is an on site out of hours task, with considerable distances involved, so has yet to happen.

We will also check back here periodically to see if this issue has been identified and resolved.

Thanks.
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Rudi De Vos
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Re: File Transfer problem with W2K8 R2 and v1.2.1.2 64 bit

Post by Rudi De Vos »

Found a latency check in the viewer code.

If the viewer send a data block and this is slower the 200ms, then an extra timout of 200 ms is added.
In most cases a send of 200ms for a 1k block indicate that the buffer is filling and we need to slowdown the upload.

There was also some other bug
https://forum.ultravnc.net/viewtopic.php?f=71&t=32713
Possible this is also related to your issue.

I don't think i can proper simulate your issue.
Are you willing todo some tests with special builds ?
RonnieM
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Re: File Transfer problem with W2K8 R2 and v1.2.1.2 64 bit

Post by RonnieM »

Rudi De Vos wrote:Found a latency check in the viewer code.

Has this latency check been introduced since v1.2.0.3 ?
If so . . . then the possibility exists that this is related to this problem.

You will know more about how the data is transmitted than I do, but with a satellite connection the general situation is that there is a minimum of a 600ms delay in receiving a response to any request (the time taken to traverse the satellite hop), but once a download or a data stream is initiated, it generally just keeps coming !

So . . . . as I ping New Zealand from the UK (Satellite ground station in Italy) . . . .
746ms
743ms
732ms
701ms

Using UltraVNC v1.2.0.3 at both ends, to a site half the length of Scotland away, via Satellite and Italy ground station :
9 MB file from local viewer to remote server
Transfer speed ramps up progressively to give 661 kb/s
Transfer time 15.3 seconds

So I don't think that really counts as a "Slow Network", other than the initial latency.


Rudi De Vos wrote:There was also some other bug

Yes . . . . . I can see some similar aspects in this report.


Rudi De Vos wrote:I don't think i can proper simulate your issue.
Are you willing to do some tests with special builds ?


In theory yes, although I can't promise a rapid response.

It would also mean putting a temporary machine at a remote site, and even then, the question is how to change the UltraVNC version on the machine remotely. The old phrase "cutting off the branch you are sitting on" springs to mind !!

So yes . . . . I can test, but you might need some patience !!!
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Rudi De Vos
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Re: File Transfer problem with W2K8 R2 and v1.2.1.2 64 bit

Post by Rudi De Vos »

I need to check .. somewere in the past the FT protocol was changed.
The FT parts was not written by me... it's digging in the code to see what's wrong.

It's a vncviewer.exe issue.
If the FT protocl it's the same in 1203 the we could test with a 1215 viewer and a 1203 server.

Testing with a different viewer is simpler then changing the winvnc.

Just checked, the FileTransfer.cpp is still the same from 2013.. this file can't be the cause... so a 1215viewer should be compatible with a 1203 server.
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