I can explain why the RDP server is disconnecting. It's because, when an RDP connection is enabled, Windows basically redirects all of the graphics rendering into an off-screen buffer and makes it available only via the RDP server. If this were a real workstation, the act of logging into the machine locally would also disconnect the RDP connection, because Windows can't use the virtual display in the RDP server and the "real" display at the same time. Actually, it could theoretically use both the virtual and real display at the same time to serve up different independent sessions, and that's how Windows Terminal Services works, but Microsoft decided to license the Windows workstation products in such a way that you can't have multiple simultaneous sessions active, and thus connecting to RDP locks the local display, and logging in locally disconnects RDP. Since WinVNC uses the local display, that's why using WinVNC disconnects RDP.
I should caution that TigerVNC does not have "3D support" on Windows per se. No WinVNC solution technically does. TigerVNC will do a much better job than RealVNC of compressing and transmitting the types of images generated by 3D apps, but actually getting those apps to display correctly in WinVNC is a challenge. Hardware-accelerated OpenGL usually bypasses the Windows GDI, and thus it bypasses the hooks that WinVNC use to determine when it's appropriate to read back, compress, and send a portion of the screen. Thus, the only way to get WinVNC to work with hardware-accelerated OpenGL is to make it poll the full screen for pixel changes, which is woefully inefficient and CPU-intensive. Some proprietary screen scraping solutions, such as HP RGS, actually hook into OpenGL in a similar manner to VirtualGL on Linux, and they use those OpenGL hooks to determine when the application has finished rendering a 3D portion of its GUI so that that portion of the screen can be compressed and sent to the viewer. No WinVNC solution does that, however. Those who are deploying Windows 3D apps remotely using open source technologies are largely doing so by running a virtual machine instance in VirtualGL, then running VirtualGL in TigerVNC or TurboVNC on Linux. However, obviously that's a non-starter with a hosted VM solution. As far as why VNC isn't connecting, you're probably running into a known issue with older WinVNC implementations and Windows 7. In order for a WinVNC implementation to work properly on Windows 7, it has to be split into multiple applications, one of which handles the GUI and the other of which handles the actual server operations. The older (free) version of RealVNC, as well as TigerVNC, don't do that, and thus they're going to be useless on anything newer than Windows XP. I would recommend that you try UltraVNC, which is supported on Windows 7. It's not going to perform as fast as TigerVNC (probably about half), but if used with the TigerVNC Viewer, it should still provide usable performance, and definitely much better than the free version of RealVNC. Good luck. On 4/4/13 10:07 AM, Levine, Adam wrote: > All, > > I am hoping for some help running VNC on a Windows Azure virtual > machine, Microsoft’s hosted VM solution (like Amazon EC2). Any help or > insight is appreciated. > > By default, Azure VMs come with RDP pre-configured. However, I am > running an application that uses OpenGL graphics, which runs very poorly > over RDP (worse than screen-scraping). Selecting an object so you can > highlight it takes several seconds, even at LAN speed. > > To overcome this, I tried to install both RealVNC (which I have used in > the past for other purposes), and TigerVNC (which is new to me, but > chose for 3D support). Both applications basically have the same problem: > > 1)When I attempt to connect to the VNC server, it successfully connects > and challenges me for a password, so there is no immediate connectivity > or firewall issue. > > 2)When I enter the password, the RDP session, if one is being used, > disconnects. I’m confused as to why RDP would even know VNC is being > used – they are totally separate applications, running on different > ports (5900 for VNC, and 3389 for RDP). > > 3)Neither RealVNC or TigerVNC give a remote desktop after logging in. > RealVNC reports that the connection has been unexpectedly disconnected, > while TigerVNC provides no message. > > A few details: > > -Only port 5900 and 3389 is open to the Azure instance. Do I need other > ports? > > -I am running VNC as an application, not a service. > > -I am attempting to connect to the same machine using both RDP and VNC. > > -I don’t know where to find any kind of logging of VNC to help me figure > out why the session is disconnecting. > > One theory I have may be screen resolution. I don’t know what the > “Native” resolution of Azure VMs are, or if they have one. The > resolution has always been determined by the RDP client, and the VM just > adjusts to match. VNC typically displays at the already-existing > resolution. > > àAdam ------------------------------------------------------------------------------ Minimize network downtime and maximize team effectiveness. Reduce network management and security costs.Learn how to hire the most talented Cisco Certified professionals. Visit the Employer Resources Portal http://www.cisco.com/web/learning/employer_resources/index.html _______________________________________________ Tigervnc-users mailing list Tigervnc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/tigervnc-users
