The game use udp, but I noticed that if the game loses one packet, the game goes crazy and the network updates stops.
The problem is that UDP is unreliable by definition, so it's normal to lose packets or to receive duplicated ones (note: this isn't "lag")....
In my case, where the connection with your server isn't optimal, after few minutes of playing I have to logoff and reconnect. Very annoying...
Please use TCP (if you prefer, by option) or let the UDP connection lose packets without stopping the game.

The game _does_ retransmit lost UDP packets. It does not assume reliability! In fact, the server measures packet loss and displays it as a per-user statistic on our administration utility.

Something else is wrong, and I'm not sure what. I've heard of situations where university dorms have routers which deprioritize UDP traffic it isn't familiar with to the point where the game becomes unplayable after a few minutes. These routers have special cases for quake/halflife/etc and you can configure them to allow it, but they obviously don't know anything about Vendetta yet.

But from another post, it sounds like you're on an ADSL connection independent from that, so I'm not sure. We can do some testing.

After asking my college IT head dude to increase the priority of Vendetta's port numbers for the PacketShaper, they went along and said they'd get to it. They do in fact have popular games listed as "multimedia", thus giving them some level of priority. So anyway, after I made this request, the lag did die down after a couple of weeks. It helped... but once in a while the connection still craps out. This is most likely due to daytime network traffic though.

IIRC, one of you devs mentioned adding Vendetta's port numbers to the national PacketShaper database or something. Has that been approved yet?