On 2012-02-01 14:22, Jakub Skoczen wrote: > I have not tried with other forms of networking yet, indeed it might > be a good idea to see how it behaves then. I am aware of the > limitations of NAT in VBox but in all honesty, I doubt that low-level > TCP stack would have much influence on the app I am trying to profile > (as long as the former works of course). > Chapter 9 of the manual has some information on fine tuning the NAT interface:
<excerpt begin> Tuning TCP/IP buffers for NAT The VirtualBox NAT stack performance is often determined by its interaction with the host's TCP/IP stack and the size of several buffers (SO_RCVBUF and SO_SNDBUF). For certain setups users might want to adjust the buffer size for a better performance. This can by achieved using the following commands (values are in kilobytes and can range from 8 to 1024): VBoxManage modifyvm "VM name" --natsettings1 16000,128,128,0,0 This example illustrates tuning the NAT settings. The first parameter is the MTU, then the size of the socket's send buffer and the size of the socket's receive buffer, the initial size of the TCP send window, and lastly the initial size of the TCP receive window. Note that specifying zero means fallback to the default value. Each of these buffers has a default size of 64KB and default MTU is 1500. <excerpt end> In addition, though I have not seen it documented specifically for VirtualBox, all NAT implementations will have some sort of state engine that tracks the connections being used. If you are creating a lot of connections then your VirtualBox may be forced to discard some, which would hopefully, be the older ones. Wireshark may help you here, and if you are seeing a lot of TCP RST packets then you've probably exhausted the inbuilt state engine. -- Message sent via my webmail account. ------------------------------------------------------------------------------ Keep Your Developer Skills Current with LearnDevNow! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-d2d _______________________________________________ VBox-users-community mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/vbox-users-community
