[vbox-dev] [PATCH] UDPTunnel : new network interface backend to allow using this to link to GNS3 and QEMU instances over the network

Christophe Devriese christophe.devriese at gmail.com
Wed May 11 08:25:28 GMT 2011

On Wed, May 11, 2011 at 10:02 AM, Nikolay Igotti
<nikolay.igotti at oracle.com>wrote:

>      Hello,
>  Idea of patch is nice, but what I don't understand is how do you implement
> reliable ethernet
> (as carrier collision and packet retransmit in real hardware is performed
> by the NIC) transport over
> potentially unreliable UDP (no guarantees on delivery or frames ordering).
> Cursory look shown no
> code for retransmit or attempts to handle ordering issue in patch.

I don't.

Why would one need, or want, reliable delivery and guaranteed in-order
packet ordering to implement ethernet, which provides neither of these
guarantees ?

At least some explanations how do you expect that to work, and tests how
> this whole feature behaves
> in heavily contended networks would be nice.

Well the patch is mainly to get GNS3 to be able to draw & start a full
network of machines, then start it up on a number of pc's and have them
communicate without any special configuration of the network. As it is
though, I'd expect it to scale very well (much better than the VDE driver at

>   Nikolay.
> On 5/11/11 3:11 AM, Alexey Eromenko wrote:
>> A letter to community:
>> UDP Tunnel networking
>> ---------------------
>> UDP tunnel is a great mechanism to interconnect virtual machines
>> running on different hosts. It is intended for advanced users.
>> Technically this is done by encapsulating guest's ethernet frames into
>> host's UDP/IP packets, and sending them to the destination. This
>> tunnel is a sort of VPN, except that UDP tunnel is not encrypted.
>> ----------------------------
>> This feature will enable GNS3 network simulator to work perfectly
>> together with VirtualBox.
>> GNS3 allows to build clouds and distributed network topologies in very
>> nice graphical way, where you can actually *draw* network topology,
>> and interconnect VMs together, even if they run on different physical
>> hosts. GNS3 is very user friendly.
>> So you all are encouraged to test UDP tunnels, and report your findings.
>> Best wishes,
> _______________________________________________
> vbox-dev mailing list
> vbox-dev at virtualbox.org
> http://vbox.innotek.de/mailman/listinfo/vbox-dev
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.virtualbox.org/pipermail/vbox-dev/attachments/20110511/dea0b594/attachment.html>

More information about the vbox-dev mailing list